ICM 1914 <» 10 CHEMICAL AND BACTERIOLOGICAL APPARATUS AND PURE CHEMICALS. BAIRD & TATLOCK (LONDON) LTD. LONDON. PRICE LIST OF CHEMICAL AND BACTERIOLOGICAL APPARATUS, ' CHEMICALS, AND REAGENTS MANUFACTURED AND SOLD BY BAIRD & TATLOGK (LONDON) LTD. CONTRACTORS TO HIS MAJESTY'S GOVERNMENT, INDIA AND COLONIAL OFFICES, J-v. MANUFACTURERS OF ASSAY, BACTERIOLOGICAL, CHEMICAL, PHYSICAL, AND PHYSIOLOGICAL APPARATUS, &c., &c. LABORATORY BENCHES, APPARATUS AND FUME CUPBOARDS, &c. LABORATORIES COMPLETELY EQUIPPED. Warehouse and Offices: 14, CROSS STREET, HATTON GARDEN, LONDON, E.C. Factory : 1 HICHAM LODGE," WALTHAMSTOW, ESSEX. Telephone! 2613 HOLBORN (2 lines). 1914. [Copyright.] Telemrimi : "BURETTE. LONDON." Cables: A. B.C. Code. 5th Edition. I CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICAL I = — H^XJfc. BAIRD &TATLOCK (LONDON) LTD. fscJEIMTIFIC INSTRUMENT MAKERS 14, CROSS STREET, HATTON GARDEN, LONDON, E.G. 93, 94, GREAT SAFFRON HILL, LONDON, E.G. Telephone Number— 2613 HOLBORN (2 lines) Telegraphic Address— " BURETTE, LONDON." Cables— A.B.C. Code, 5th Edition. BAIRD &TATLOCK (LONDON) LTD, 3 BAIRD &. TATLOCK (LONDON) LTD. PREFACE. I N placing before our clients a new edition of our Catalogue of Chemical and Scientific Apparatus, we would call attention to many new and improved forms of apparatus we have introduced into this list. Prices of all goods have been carefully revised and fixed at the most reasonable ratio consistent with quality. We shall as heretofore endeavour to supply only the best quality of goods. For School use we have included a second quality of a few articles, but these will only be supplied when specially ordered. Prices quoted are subject to market fluctuations. LABORATORY FITTINGS. — This has now become a very important branch of our business, and we have fitted up many of the principal new laboratories both in this country and abroad. In our list we have shown a few designs of Laboratory Benches and other fittings, but these are as a rule better made to suit the rooms required to be fitted up as laboratories, and on receipt of a ground plan we should be pleased to send specification and quotation for the fittings we would propose. All fittings are made of the best material and workmanship under our supervision at our Walthamstow Factory. OUR APPARATUS WORKSHOP is fully equipped for the manufacture of almost any piece of apparatus, and we are always prepared to make any new piece of apparatus to our clients' design on the most reasonable terms. COPPERSMITH SHOP.— All our supply of Drying Ovens, Stills, and Condensers, etc., are entirely of our own manufacture, and we shall be pleased to make any pattern not shown in our list to order. GLASS-BLOWING. — As it is impossible to catalogue every piece of Glass-blowing required for Scientific research, we have experienced Glass Blowers on the premises to make any special piece of apparatus required at short notice. . GLASS TUBING. — For Glass-blowing, our stock of this is of the very best quality obtainable, and we guarantee that it will not devitrify in the flame, and that it is of uniform hardness and quality, and from the same stock as our own Glass Blowers' work. CHEMICAL REAGENTS AND MICROSCOPICAL STAINS.— We hold a large stock of these, including Merck's guaranteed reagents, and every care is taken to ensure purity. They are all carefully selected, of the best manufacture, and the most important, tested in our own Laboratory, so that cus- tomers may rely on their purity and accuracy. FOREIGN ORDERS. — Clients desiring to open a new account should send the usual business references or a remittance for the amount of order. For the convenience of our foreign clients we are prepared to obtain and ship with our goods any other Manufacturers' Apparatus at lowest prices. BREAKAGE IN TRANSIT. — We do not hold ourselves responsible for breakage in transit, every care being taken with the packing, but we shall assist our customers in recovering loss from the Carriers who are responsible. EMPTY CASES AND BOTTLES.— We allow full value for all our empties returned in good order, carnage paid, within one month from date of invoice. When orders are sent we should feel obliged if, as far as possible, date and number of Catalogue is stated. Correspondence should all be sent to — BAIRD & TATLOCK (LONDON) LTD., 14, Cross Street, Hatton Garden, London, E.G. And when ordering our Goods through Agents or Local Dealers, Customers would greatly oblige by stating that they must be obtained from BAIRD & TATLOCK (LONDON) LTD. London, 1914. CROSS STREET • HATTOTST GARDEK, E-C BAIRD &.TXTLOCK. (LONDON) LTD CONTENTS. Assay Apparatus Bacteriological Apparatus Balances and Weights Botanical Apparatus and Plant Physiology Cement Testing Apparatus Centrifugal Machines Chemical and General Apparatus Chemical Physiology Chemicals and Reagents Electric Furnaces Electric Baths and Ovens Filter Paper Gas Analysis Apparatus Graduated Apparatus Hygiene, Apparatus for Teaching Laboratory Fittings v Leather Testing Apparatus Meteorological Apparatus Microscopes and Accessories Milk Analysis Apparatus Oil Testing Apparatus Paper Testing Apparatus Physical Apparatus (see Separate List). Physical Chemical Apparatus I Physiological Apparatus (see Separate List). Polariscopes and Saccharitneters Pyrometers and Calorimeters Refractometers Scientific Books Seed Testing and Soil Analysis Apparatus Sewage Analysis Apparatus Silica or Quartz Apparatus Spectroscopes and Polariscopes Standard Solutions, Bacteriological Stains and Chemicals Volumetric Apparatus Water Analysis Apparatus Section Section Section Section Section Section Section Section Section Section Section Section Section Section Section Section ^ •: • :, No. 24 1 No. 5 No. 7 No. 13 No. 3 No. 6 No. 3 N.) 25 No. No. No No. 22 No. 1 N it .M No. 4 • . II l- Section No. 1 6 Section No. 20 Sections Nos. 17 & 18 Section No. 10 Pages No-. 1173 — 1186 tion No. 19 Section No. 12 Section No. 6 Section No. 20 Section No 25 Section No. 21 Section No. 12 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. The following Catalogues will be sent on application :— (A) CHEMICAL APPARATUS AND REAGENTS. Containing Gas Analysis, Cement Testing, Paper Testing, Physical-Chemical and Meteorological Apparatus, and including the following sections, which are also published separately : — Laboratory Fittings, Sinks, Traps, Gas and Water Taps, etc. Bacteriological Apparatus. Microscopes and Accessories. Balances and Weights. Chemical Apparatus, etc. Botanical Apparatus and Plant Physiology. Milk Analysis Apparatus. Oil Analysis Apparatus. Pyrometers and Calorimeters. Seed Testing Apparatus. Assay Apparatus. Chemicals and Reagents, Standard Solutions, Bacteriological Stains, etc. Spectroscopes and Polariscopes. (B) PHYSICAL APPARATUS. Containing Apparatus for Introductory Physics, including Laboratory Tools, Drawing Instruments, etc. Glass and General Chemical Apparatus required in Physical work. List of Chemicals for use in Physical work. Apparatus for work in Practical Mechanics. Surveying Apparatus. Mining Apparatus. Meteorological Apparatus. Sound, Apparatus for experiments on. Heat, Apparatus for experiments on. Light, Apparatus for experiments on. Magnetism, Apparatus for experiments on. Electricity, Apparatus for experiments in Electricity. (A) Electrodynamics. (B) Electrostatics. (C) PHYSIOLOGICAL APPARATUS. Containing Blood Testing Apparatus. Urine Testing Apparatus. Microtomes. Dissecting Sets, etc. STREET • HATTOTST GARDEN, E- C X JO X i D J ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICAL BAIRD &TATLOCK (LONDON) LTD. •g o "§ a a o >> s a e II u CROSS STREET • HATTO>J GARDEN, E- C LABORXTORY FITTINGS Benches, Fume Cupboards, etc. Sinks Fireclay Channels Water Taps Gas Taps Bench Fittings 14-34 35-39 40-41 42-49 50-52 53-56 Laboratories completely equipped. Estimates given, upon receipt of ground plan and full particulars. 14. CROSS STREET, HATTON GARDEN, EC BAIRD & lATLOCK (LONDON) LTD. gr^S^^^Ss" it^^&Pa^ ^^^5^^^r= The following are the different Sections in our Catalogue. Those marked * are also printed separately. Pages Nos. Section No. 1.* Laboratory Fittings 14-56 2.* Bacteriological Apparatus 57-161 3. Chemical Physiology Apparatus 162-192 4.* Microscopes and Microscopical Accessories 193-320 5.* Balances and Weights 321-382 6.* Chemical Apparatus 383-816 7.* Botanical Apparatus 817-842 8. Gas Analysis Apparatus 843-886 9." Milk Analysis Apparatus 887-894 10. Refractometers 895 - 902 11.* Oil Analysis Apparatus 903-926 12. Water Analysis Apparatus 927-933 13. Cement Testing Apparatus 934 - 946 14. Leather Testing Apparatus 947-949 15. Paper Testing Apparatus 950 - 951 16. Physico Chemical Apparatus 952-976 17.* Pyrometers 977-1006 18.* Calorimeters 1007-1022 19.* Seed and Soil Analysis Apparatus 1023-1042. 20.* Spectroscopes and Polariscopes 1043-1078 21. Volumetric Apparatus 1079-1087 ] 22. Anatomical Models 1088-1105 23. Meteorological Apparatus 1106-1124 24.* Assay Apparatus 1125-1172 25.* Chemicals 1187-1246 rf&if*^. l\'jM -* ^ *•* In 14 • CROSS STREET • HATTOTM G P/AV ti w jA ARDETsf, E-C- fjjt SECTION No. 1. Laboratory Fittings, Benches, Sinks, Taps, &c. For the Equipment of Chemical, Physical and Physiological Laboratories. The following illustrations which are given may serve as a guide in the fitting up of new Laboratories. They are, however, only a few selections from various patterns which we have made. Any pattern of Bench can be made to order. On receipt of a ground plan of the proposed Laboratory, we shall be pleased to forward sketches showing the arrangement for Benches, 6-c.. we would recommend. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 2 o A •a u U c a •o o O w E- 83 z B. D CJ CROSS STREET • HATTOTST GARDEK, E- C 10 BAIRD & TATLOCK (LONDON) LTD. Estimates given for all kinds of Laboratory Fittings, upon receipt of ground plan. Trinity College, Dublin, New Physical Laboratory. Ground Plans of Fittings. Fittings throughout by Baird 6? Tatlock (London) Ltd. riRST FLOOR PLBN Trinity College, Dublin, New Physical Laboratory. Ground Plans of Fittings. Fittings throughout by Baird & Tatlock (London) Ltd. SECOND H.OOB. SCIENTIFIC APPARATUS AND PURE CHEMICALS 18 11 BAIRD &TATLOCK. (LONDON) LTD. We give below a number of Laboratories fitted up by us in recent years. Estimates given for all Laboratory Fittings on receipt of Ground Plans. LONDON BELFAST DUBLIN CORK WATERFORD EGHAM CANTERBURY Hampstead Hospital Birkbeck Institute (London) Birkbeck Institute (London) Latymer Upper School (Hammersmith) London University (South Kensington) Imperial Institute Holborn Estate Boys' School Holborn Estate Girls' School Merchant Taylors' School Merchant Taylors' School Merchant Taylors' School St. John's College (Battersea) James Allen's Girls' School (Dulwich) Lister Institute of Preventive Medicine Royal Military Academy (Woolwich) Royal Naval College (Greenwich) William Ellis Endowed School Clinical Research Association Brown Institution Kennington Girls' School . . College of Domestic Science University College University College University College University College St. Bartholomew's Hospital London Hospital Middlesex Hospital Westminster Hospital St. George's Hospital Infants' Hospital. . St. Mary's Hospital Cancer Hospital Bolingbroke Hospital Dr. Mond Metropolitan Water Board Mr. F. W. Harbord, Victoria Street Drs. Moritz and Morris Messrs. Burroughs, Wellcome & Co. Dr. Oberlander Camphor Ltd. Messrs. Clayton Beadle & Stevens Mr. R. W. Sindall Local Government Board . . Sir J. Cass Technical Institute Zoological Gardens Royal Waterloo Hospital . . Local Government Board . . British Radium Corporation Messrs. Bryant & May Homoeopathic Hospital St. Mark's College (Chelsea) Queen's College Queen's College Trinity College Trinity College Messrs. Guinness, Sons, & Co. Ltd. Presentation Brothers College Ursuline Convent Royal Holloway College King's College Bacteriological Laboratory Chemical Laboratory Metallurgical Laboratory Chemical and Physical Laboratories Chemical Laboratory Chemical Laboratory Chemical Laboratory Chemical Laboratory Physical Laboratory Botanical Laboratory Botanical Museum Chemical Laboratory Botanical Laboratory Directors' Laboratory Chemical Laboratory Chemical Laboratory Chemical Laboratory Bacteriological Laboratory Bacteriological Laboratory Chemical Laboratory Chemical Laboratory Physiological Institute Chemical Laboratory Pharmacological Laboratory Chemical-Physiological Laboratory Physiological Laboratory Pathological and Bacteriological Laboratories Bacteriological Laboratory Pathological and Bacteriological Laboratories Pathological and Chemical Laboratories Bacteriological Laboratory Chemical Laboratory and Dispensary Bacteriological Laboratory Pathological Laboratory Private Research Laboratory Chemical and Bacteriological Laboratories Metallurgical Laboratory Brewing Laboratory Chemical Laboratory Research and Analytical Laboratory Research and Analytical Laboratory Research and Analytical Laboratory Research and Analytical Laboratory Chemical Laboratory Chemical and Physical Laboratories Pathological Laboratory Bacteriological Laboratory Pathological Laboratories Chemical Laboratories Chemical Laboratories Pathological Laboratories Physical Laboratory Physiological Laboratory Pathological Laboratory Physical Laboratory Botanical Laboratory Research and Analytical Laboratory Chemical Laboratory Chemical Laboratory Chemical Laboratory Chemical Laboratory 14 -CROSS STREET • HATTCTNr GARDETST, E- C 12 BAIRD &TATLOCK. (LONDON) LTD. CHELMSFORD CAMBRIDGE HOLT KHARTOUM EPSOM MAK t. BOROUGH TREDEGAU v VALE . . Fowr.v PlNEWOOD SUKBITON WINCHESTER . . CAIRO PUDSEY HARLOW CHELTENHAM . . BRIGHTON \\ (HiDHALL SPA RANGOON ASHFORD HARROW LANCING LIVERPOOL SHEFFIELD HEADING CRANLEIGH READING County Technical Laboratoriea New Museums University . . Gresham School Gordon Memorial College . . Nile Floating Laboratory . . Royal Medical Benevolent College Grammar School County School County School Grammar School Sanatorium High School Eastman's Naval Academy Cavalla School Fullneck School, near Leeds Silcoates School Harlow College St. Paul's College Sussex County Hospital Dr. Williams Hospital County School County School Lancing College . . Messrs. Lever Brothers Government Testing House Reading School . . Cranleigh School . . Bradfield College. . Chemical I.»U« riolocical and P«tholofk*l Laboratory Chemical and Ph viical Laboratoria* .ototkal and OMflrieal Uboratortw tolorical and OMorioU UboratoriM Chemical Labontory at .iii.l Itiyucal I-aboratoric* ( lirimcal Laboratory i ).• inical Laboratory Bacteriological Laboratory Chemical Laboratory Chemical Laboratory Chemical laboratory Chemical and I'hywtaJ Laboratonea »:al Laboratory Laboratofy Pathological and Bacterloloflcal Laboratoria> r. • . . ,: I : .' I '. , ' i: . Chemical and Phyxical LaboratoriM Chemical and Physical LaboratorlM Chemical ami Phydcal Laboratoria* Chemical Laboratory Mctalturi(ical Laboratory Chemical and ItiyMcal l-»l».r«tori«» Chemn.il ..;: i i'hytaal LaboratoriM Chemical and Physical LaboratoriM Set of Evaporating Cupboards, Steam and Hot Air Ovens, Royal NavaUCollege. Greenwich. as fitted by us. Price for special Copper Baths, Ovens. Stc.. on application 5 !II| i'~-a o c Z "S a "- 8 If 1> >SH rt rt <« .S 5' G o 2 a •- j= » g s^-s-s-s •* u X J3 ?- g S £ S "g S -g -C O ,/r ^ rt in ^ o-gja 2 - S ^ h •5 «-S 25 5 >- > - s »*'S 14 BAIRD &TATLOCK. (LONDON) LTD, 101 101' Chemical Laboratory Bench, for two students, 8 ft. by 2 ft. 6 in. by 3 ft. high, with teak top, finished ij-in. thick, on bench top a double set of plate-glass reagent shelves with wood panelled back to same. Two two-way lever-handled gas taps (Fig. 250), with upright movable rods over same, to be used as retort stands, etc. ; under bench top is fitted one white glazed fireclay sink, 14 by 10 by 6 in., with side overflow. Over sink one swan-necked gun-metal water tap, with two small screw-down side taps (Fig. 229), with corrugated nozzles for indiarubber tubing connections. Each student's space is provided with a set of three drawers and three cupboards, all fitted with locks and keys. In centre of bench one general cupboard with swing flap, and zinc lined box for waste paper, etc. All facings of bench in pitch pine polished, teak top of bench prepared with paraffin wax £23 10 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 15 BAIRD &TXTLOCK: (LONDON) LTD. 102 102T Chemical Laboratory Bench arranged for four students. Size of bench, 8 ft. long, 5 ft. wide, and 3 ft. high, with teak top, ij in. finished thickness, and external framing in selected pitch pine, polished ; internal framing best deal. The bench is fitted with four drawers and four cupboards on each side with a 9 in. movable shelf in centre. Teak knobs and spring catch fitted on doors and best brass pulls on drawers. Along centre of bench top two teak trays are fitted into top, but movable for reagent bottles. Trays project £ in. above top, each 3 ft. long, 9 in. wide, with white marmorite top. Each student's space is provided with two gas leads on bench top (Fig. 265) and controlled with gas tap (Fig. 264). Under ledge, fixed at each end of bench, one combination sink, white glazed inside and out, with overflow waste box at each side, 10 by 8 by 8 in., fitted with galvanized wire baskets in each. Over each sink one swan-neck three-way water tap, with two side leads (Fig. 229). Two Incandescent Burners, fitted on standards as shown ; all water and gas supply pipes fitted and left ready for connecting up at one end of bench. No waste pipe or locks included, but these can be supplied if required £39 0 -CROSS STREET • H ATTORN GARDE1ST, E-C BAIRD &TATLOCK (LONDON) LTD. ET, 03 103 Chemical Laboratory Working Bench, for eight students. Illustration slu.ws mr.1,,,,1 of arranging cupboards and drawers with knee space between, two cupboards and three drawers for each student ; two white enamel sinks 20 by 10 by 6 in No 143 acccsMh!,- from either side of bench; one gun-metal water tap (Fig. 209) for every two stud.-ut, one two-way gas tap (Fig. 250) for each student ; one cane glazed fireclay acid tr.iii (Fig. 152) for each bench. The cupboards are arranged so that all gas and water pipes can be examined conveniently. Size of bench, 14 by 4,', by ; ft. Price com- plete with pitch pine fronts and teak top, finished ij in. thick" and all i tans but without gas and water connections to same . . Prices with Oak Framing, or any other wood selected, on 'application. 104 Physical Laboratory Bench for Eight Students. Size, 14 ft. by 4 ft. 6 in. by 2 ft. 9 in. high, with teak top, finished ij in. thick, prepared with paraffin wax. Two cupboards and four drawers to each student ; cupboards fitted with locks ; facings of under part in pitch pine, varnished. At either end of bench, one half-round white enamelled fire- clay glazed sink, 12 by 7 by 6 in. ; over each sink, one swan-neck gun-metal screw- down water tap (Fig. 227) ; two sets of four-way lever-handle gas taps (Fig. 253) fitted on bench top, as shown (one tap to each student). The illustration shows a method of providing suspension rails over the bench top ; two steel bar suspension rails full length of bench are fixed 2 ft. high on iron standards, well enamelled, and securelv bolted to teak top. The rails are easily removed if required. Price, with gas taps and with gas supply pipe brought to end of bench ready for connecting £43 0 0 A £52 0 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 105 105T Laboratory Bench for Four Students. Size, 7 ft. by 4 ft. by 3 ft. high, teak top, ij in. finished thickness. All external facings of selected pitch pine, polished. This bench is arranged for two students on either side, each having one double cupboard and two drawers. In front of sink on either side is fitted a swing flap with zinc tray under for waste paper, etc. Under this is fitted one general cupboard. Over bench top is fitted two rows of reagent shelves. One sink, 20 by 10 by 6 in. ; white glazed with two | in. screw valve gun-metal water taps over, four double-way gas taps, one acid trap under sink. Cupboards fitted with locks £21 5 106 106T Portable Bench for Four Students, teak top, finished ij in. thick, pitch pine legs and framing, fitted with shelves for reagent bottles, one white enamelled fireclay sink, 14 by 10 by 6 in. (Fig. 137), four two-way gas taps (Fig. 250). Size of bench, 7 by 4 by 3 ft. high. Price, with gas and water taps, but without gas and water connections £9 10 CROSS STREET • HATTON GARDEN, E-C BAIRD &TATLOCK (LOM)ON) LTD. 107 107T Lecturers' Bench 8 ft. by 2 ft. 6 in. by 3 ft. high, for chemical or physi< aJ work ; with teak top, finished I J in. thick. All facings of pitch pine, varnished. ( >m- white glazed 14 by 10 by 6 in., fitted on right end of bench ; one pneumatic trough with plate-glass front, 20 by 15 by 15 in., on left end of bench. Over tin- sink ami pm-innatic trough is fitted one of our screw-down water taps to fold under top \vln-n not required. The sink and pneumatic trough are also fitted with hinged cover to fold over end of table when in use. Bench has three cupboards (all fitted with li>< ks ami keys) an-l MX drawers. On top of bench, two gas nozzles (Fig. 265), with control taps (Fig. 264) under ledge of bench convenient to lecturer. Price, with gas and water taps, but without connections to same ...... . . 1 1 8 10 0 ^Btrz- ' 108 108T Lecturers' Table, with teak top, finished ij in. thick, pitch pine framing, two double cup- boards, five drawers, and one shelf in knee space ; one white glazed fireclay sink, 14 by 10 by 6 in. with gun -metal water tap (Fig. 222) to fold inside when not in use, and fitted with teak folding cover ; one pneumatic trough, with folding water tap (Fig. 222), also provided with teak folding cover ; and two two-way gas points, with taps (Fig. 250), in front of bench. Size of bench, 7 by 3 by 3 ft. high. Price, with necessary taps, but without gas or water connections £15 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 19 BAIRD &TATLOCK (LONDON) LTD. BAIRD &. TATLOCK (LONDON) LTD. 110 Physical Bench for Eight Students. Size. 14 tt. by 4 ft. i, in. l,y _• ft. 0 m high with teak top. finished ij in. thick. All f.u m.^ ,,f U-st pit. h pine. Varnished. <)nc double cupboard and six drawers to each working space. K.i. h < upboar.l i^ titled wit! and key, all to differ. This bench is tilted with right ».i, H,,.- gas is controlled by our new pattern gas taps (I - U-dge at Over the bench top is fitted the steel suspension raiN. Pn, . , with gas taps and with gas supply pipe brought to end of bench ready for connecting £52 0 d in1 in Physical Table for Four Students, 8 ft. long, 4 ft. 6 in. wide, and 3 ft. high, teak top. finished ij in. thick, on strong pitch pine legs well framed together ; with four drawers on either side, and fitted with two two-way lever-handle gas taps (Fig. 250). and stipplv pipe brought to end of bench ready for connecting. Movable steel suspension rails as shown Benches figured with suspension rails can be supplied without as required. £11 10 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. " WJ S S o d o C 7? J 1 «-> IE ., 73 o ^> § 9 "S -a 2 3 § I •S £ eo o o g «<3|a o g r: o S. •a I e XI 3 « £ -s ? * S '«-sS § ^-2!! "S — ^-. ea O o U H €&ii Ifl^ *i? BO * K ° " >, S .§ .x 5 §• « 'S 5. o S m- o " sl & I f) •** «• c e-js 8 W 0 0 B a S 1 s £ o a : I •o .22 ra -4-j n J3 - sr. lisli.-,|, K|.iss front, ends, and top. Two sliding doors, counterpoised with Wrights, suspended with best catgut liiu-s over strong pullrys as shown under. The pulleys are fixed on wall, over wood guide for weights to travel in. The slate base is fitt.-d with four gas points (Fig. 265) for working, and one to flue, with control taps 264) outside under edge, fitted in slate^sole, at left-hand side, one sink 8 by 6 in., white glazed inside, cane outside (Fig. 139), water bend fitted over same with control tap in front as shown (Figs. 243-244). All the gas taps are fitted ready for connecting up to gas supply at one point. Water tap and bend fitted ready for con- necting to water supply, but no waste supplied. Price, without back ready for fixing to wall. £14 14 0 I xtia price for white tiled back on appli- cation. 118 Plan of Base. BAIRD &TATLOCK (LONDON) LTD. 119 119T Sink, Enamelled Fireclay, white glazed inside and out, internal measurements 27 in. long, 15 in. wide, and 8 in deep, for fitting against wall as shown. A teak frame fitted over sink with draining board at right-hand end, 3 ft. long and 2 ft. wide. At back of sink on right hand is a teak pegged draining board, and the left-hand end is covered with white glazed tiles. A strong gun-metal standard with three gun-metal water taps, No. 209 f in. bore, are fitted over sink ; the standard is fitted with back-nut and unions for connecting up to water supply, and the sink is supported on galvanized iron cantilevers, or wood legs if cantilevers are not suitable £770 Above can be fitted with i trap (Figs. 201 or 204). in. cane glazed waste pipe as on illustration, or with ii in. S or CROSS STREET • HATTOTST GARDETST, E-C 121 21T Balance Case. The above illustration shows a rase t<>, six Halair.es suitable toi tmni; on w;ill either on iron cantilevers let into the wall, or on wood bracket legs, over .ill si/<- 10 ft. 6 in. long, i8ir. wide, 24 in. high at front, and 29)11. high at l>;u k. d»M>r ^p;u:c about _> > in. wide, sliding doors counterpoised on lead weights hung over pulleys on catgut All doors, ends, top and divisions of glass, framing of oak or mahogany polished with a tc'ik sole, I in- a! ove ill- tion is shown for fitting against the wa'l without auv b:u k . £9 15 0 Similar Cases fiin bt sufflitd t<> suit any number a/ /iaianfts required anil any site. 122T Lecture Blackboard, with four plate - glass writing surfaces, each 5 ft. by.; ft., counter] •• with lead \\vights, and hung on catgut lines sliding over ! pulley wheels. Pitrli pine fram- ing and standards polished f'>r fixing to walls ; total height, 12 ft. 123T Lecture Blackboard, as a i but with only two plite-gla^ writing surfaces, each 5 ft. by 3 ft. ; total height, 10 ft. 6 in. £23 10 0 £12 15 0 122 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &X\TLOCK (LONDON) LTD. 124 124T Apparatus or Museum Case, 6 ft. long by 7 ft. 9 in. total height. Made in oak or mahogany polished, lower portion 2 ft. back to front, fitted with two pairs folding glass panelled doors with one shelf in centre, upper portion 9 in. back to front, with two pairs hinged glass panelled doors forming two compartments, each compartment having four plate- glass movable shelves, polished on edge, fitted on Tonk's adjustable rack and brackets. Between top and bottom portion a museum case with sloping glass panelled top, made to hinge up, all doors fitted with locks and keys .. .. .. .. .. £19 10 0 CROSS STREET • HATTCW GARDETST, E-C 28 or BAIRD &. WLOCK (LONDON) LTD.* 25' 125 Museum Case, 6 ft. long by 7 ft. 9 in. total height, bottom portion 2 ft. deep, top portion 9 in. deep inside. Made in oak or mahogany, lower portion fitted with two single cupboards (with one shelf in centre), with glass panelled doors. Between the cup- boards two nests of five drawers as shown on sketch, upper portion fitted with two pairs hinged glass panelled doors forming two compartments, each compartment having four plate-glass movable shelves with polished edges fitted on Tonk's adjustable racks. Between top and bottom portion a museum case with sloping glass panelled top, hinged to lift up. All doors hinged and fitted with locks and keys . . A £21 10 0 BAIRD &TATLOCK (LONDON) LTD. 126 126T Apparatus Cupboard, 6 ft. long by 7 ft. 6 in. total height. Made in best pitch pine, polished, lower portion 21 in. back to fiont fitted with two pairs hinged wood panelled doors, forming two compartments, with one shelf to centre of each ; upper portion 13 in. deep, fitted with two pairs hinged glass panelled doors, forming two compart- ments, with four movable shelves to each, fitted on Tonic's1 adjustable rack and brackets. All doors fitted with locks and keys £11 0 0 CROSS STREET- HATTCnST GARDE1ST E-C 30 BAIRD &TATLOCK (LONDON) LTD. 127 57T Apparatus Cupboard, made in best pitch pine polished, size g ft. long and 7 ft. 9 in. total height, lower portion 21 in. back to front and 3 ft. high, fitted with two pairs of sliding wood panelled doors on ball-bearing pulleys and track for same, forming two compart- ments, each having one shelf in centre, upper portion 13 in. deep, fitted with two pairs glass panelled doors on pulleys as before, and forming two compartments with movable shelves to each, fitted on Tonk's adjustable rack and brackets, all doors fitted with locks and keys £18 0 0 .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIR-D &L TATLOCK (LONDON) LTD. 128 128T Museum Case, 10 ft. by 4 ft. by 3 ft. 10 in., exclusive of top shelves, made in mahogany, with sliding glass panelled doors running on ball bearing pulleys, under portion fitted with one movable shelf inside, upper part fitted with sloping hinged doors, at back with mirror glass. Fitted on top are three plate glass shelves adjustable on brass uprights. All cupboards fitted with locks £37 10 0 BAIRD &.TATLOCK (LONDON) LTD. 129 129T Draining Boards, of teak, adapted to hang on wall at side of sink, and fitted with solid teak pegs with tapered ends as illustrated, (a) Si/r ; ft. high by 2 ft. broad each (b) Si/.c 2 ft. high by i ft. 6 in. broad Any other sizes made to order. £1 2 15 Al29r Laboratory Truck, made of teak, length 36 in., height 47 in., width .'<> in. Mounted on rubber tyred wheels, and fitted with six sliding trays, 23 in. by 15$ in. inside. The four top trays are 3 in. deep, and the 2 bottom trays 2 in. deep. Price complete as illustrated .. •• •• •• •• £7 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &. TATLOCK: (LOM>ON) LTD. 130 131 130T Museum Case or Apparatus Cupboard, made in best pitch pine, lower part fitted with three wood panelled doors, upper parts fitted with three glazed doors, two sloping glazed doors between upper and lower portions, four movable shelves on patent fittings in upper part, one fixed shelf to lower portion, all doors fitted with locks and keys. Price, made in pitch pine, 7 ft. 6 in. by 5 ft. 6 in. ; depth of top portion, 14 in. ; depth of lower portion, 22 in. .. .. .. .. .. .. each £12 10 0 Prices in Mahogany or Oak on application. 131T Apparatus Cupboard, made in pitch pine. Size, 7 ft. 6 in. by 4 ft. Upper portion with two glass doors and four movable shelves. Cupboards in under portion with wood panelled doors, and shelf to centre, all doors fitted with locks and keys ; depth of top portion, 13 in. ; depth of lower portion, 20 in. . . . . . . . . each £800 Prices in Mahogany or Oak on application. 132 133 134 132T Laboratory Stools, of pitch pine, varnished, with shaped elm top ; height, 27 in. ; each, 9/6 ; per dozen £580 133T Laboratory Stools, of selected deal, varnished, with plain top ; height, 27 in. ; each, 8/6 ; per dozen £4 16 0 134T Laboratory Stools, of pitch pine, with seat to raise and lower by means of iron screw each £014 6 14- -CROSS STREET • HATTOTST GARDEN, E-C BAIRD 7 by 17 by g in. .. 30 by 17 by 9 in. . . „ 36 by 17 by 9 in. . . (Sec Figs. 167 to 169 for Plugs and Gratings suitable for above.) 153 154 155 156 £0 14 0 £0 18 tl 4 £1 6 tl \2 157-166 Laboratory Sinks, fireclay, white enamelled inside, cane gla/cd outside, with overflow 157s Measurements outside, 18 by 12 by Sin. 158s ,, „ 24 by 16 by 7 in. 159s ,, ,, 24 by 16 by 10 in. 160s ,, 24 by 18 by 10 in. 161s ,, 27 by 18 by 10 in. 162s ,, 30 by 18 by 10 in. 163s ,, ,, 33 by 18 by 10 in. 164s .. 36 by 18 by 10 in. 165s ., ,. 42 by 24 by 12 in. 166s 48 by 24 by 12 in. £0 13 0 £0 15 6 £130 £1 4 £1 S £1 11 £1 14 6 £1 17 6 £3 10 0 6 6 0 £406 The prices of Sinks Nos. 153 to 166 do not include Brass Gratings, etc. See Nos. 167 to 169. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE BAIRD &TATLOCK (LONDON) LTD. 167 168 169 167s Brass Plugs, to suit Sinks Nos. 153 to 166 . . each 168s Brass Plugs, washer for waste and overflow, with nut and union, 3 J in. at flange, 2 in. out- let, with plug to suit Sinks Nos. 153 to 166 each 169s Grating, with nut and bent or straight union, to suit Sinks Nos. 153 to 166 £040 £096 £0 11 0 170-171 Laboratory Combination Sink, with white glazed corrugated drainer and overflow, white glazed inside, cane glazed outside — 170s 36 by 21 by g\ in. outside .. .. .. .. .. .. each £2 14 0 171s 48 by 24 by 9* in. „ ......,,£440 (Brass Plugs and Gratings extra, see Nos. 167 to 169). 172-173 Laboratory Combination Sink, as above, white glazed inside, cane glazed outside, with cane glazed supports — 172s 36 by 21 by g£ in. outside. . 173s 48 by 24 by 9^ in. „ (Brass Plugs and Gratings, see Nos. 167 to 169. each £3 18 0 £570 CROSS STREET- HATTOTST GARDETST, E- C 38 174 174s Combination Sink, of porcelain enamelled fireclay, with 6 in. back, patent overflow with cover, pedestals, patent wood nim in front of sink, wood drainer, soap tray, hot and cold gun-metal taps, 2 in. indiarubber plug, gun-metal washer, union for waste, and chain with stay. Size 48 by 21 by f)\ in. . . . . . . . . each £8186 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIR.D &TATLOCK (LOM)ON) LTD. Glazed Channels and Pipes of Special Designs FOR LABORATORIES. These channels or pipes have been designed for carrying off waste from sinks, etc. They can be conveniently used for carrying waste under floor from sinks in Laboratory Benches, or as waste channels for distillation work under bench top. Where strong acids or mercury are liable to get into waste pipes these channels, which are acted on by neither, are much to be preferred to lead pipes. Except numbers 175, 176, 195, 196, all are open at top (J in. section), with the top edges slightly turned in to prevent splashirig or overflow. All Pipes are White Glazed inside, Cane outside. 175s 175-176 Section White Glazed Fireclay Pipe, 24 in. long by 4 in. inside diam. 177-178 each 176s White Glazed Fireclay Pipe, 24 in. long by 3 in. inside diam. 177s White Glazed Fireclay Channel, £ section, 24 in. long by -4 in. diam. inside 178s White Glazed Fireclay Channel, | section, 24 in. long by 3 in. -diam. inside £0 £0 £0 £0 179-180 Section 181-182 179s White Glazed Fireclay Channels, open at top, f section of complete pipe, top edge slightly turned inside to prevent splashing, size 24 in. by 4 in. inside . . . . each 180s White Glazed Fireclay Channels, as above, but 24 in. by 3 in. inside 181s White Glazed Channels, as above, but with stop end and spigot outlet, size 24 in. by 4 in. inside . . . . . . . . . . . . . . ... each White Glazed Channels, as above, but 24 in. by 3 in. White Glazed Channels, as Fig. 181, but without spigot outlet, size 24 in. by 4 in. inside . . . . . . . . . . . . each White Glazed Channels as Fig. 182, but 24 in. by 3 in. .. 182s 183s 184s Section. £066 £066 £086 £086 £076 £076 185-186 187-188 185s White Glazed Channels, as Fig. 179, but with spigot outlet in centre, 24 in. by 4 in. each 186s White Glazed Channels, as Fig 180, but 24 in. by 3 in. 187s White Glazed Channels, with junctions for three pipes, 24 in. by 4 in. 188s White Glazed Channels, with junctions for three pipes, but 24 in. by 3 in. £076 £076 £0 14 6 £0 14 6 CROSS STREET • HATTCHST GARDEN, E-C- 40 BAIR.D «k TATLOCK. (LONDON) LTD. 190 189T190" White Glazed Channels, with right (No 189). or left (No. 190), hand junctions for two pipes, 24 by 4 in. .. /. . . . . . each £Q 1 1 6 191-192* White Glazed Channels, with right or Mt hand jimr.tt.. !,,,t .- , in l.y .; UK .. .. .. , to it 6 193-194 White Glazed Channels, with junctions for two pipes, 24 by 4 in White Glazed Channels, with junctions for two pipes, 24 by 3 in. White Glazed Fireclay Pipes, with junction end, size 18 by 4 in. inside White Glazed Fireclay Pipes, with junction end, size 18 by 3 in. inside 195-196 r.l" ll 203-204 each £059 £059 £099 £059 £096 £0 10 6 £096 £0 10 6 205-207 205s White Glazed Pipe, straight i| in. diam., 2 ft. for connecting from sink to channels each £040 206s White Glazed Pipe, straight, i$ in. diam., 2ft. 6 in. for connecting from sink to channels ,. £050 207s White Glazed Pipe, straight, li in. diam., 3 ft. for connecting from sink to channels .. £066 197-198 199-200 201-202 White Glazed Pipe, bent at right angles, 4 in. inside diam. White Glazed Pipe, bent at right angles, 3 in. inside diam. .. White Glazed Pipe, slow bend at half right angle, 4 in. diam. White Glazed Pipe, slow bend at half right angle, 3 in. diam. S Trap, for connecting to waste pipe under sinks, i£ in. bore of white glazed fire- clay, with screw plug at end for cleaning S Trap, as above, 2 in. bore ditto, ditto . . P ,, ,, i.1, in. bore ditto, ditto .. P 2 in. bore ditto, ditto .. * * "7^ (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS! BAIRD &TATLOCK (LONDON) LTD. Water Taps Specially Designed by us for use in Laboratories. 208 209 210 208s Water Taps, of gun-metal, £-in. bore, with ebony lever handle screwed f in., with boss for connection to supply . . . . . . . . . . each 4/- ; per dozen 209' Water Taps, of gun-metal, with screw-down valve, corrugated nozzle, and screwed boss for lead joint — Bore . . . . . . . . J-in. f-in. i-in. J-in. Boss screwed . . . . . . f-in. f-in. i-in. £-in. Each .. .. .. 41- 4/- 6/- 8/6 Per dozen .. 46 / 46/- 69/- 98/- 210s Water Tap, of gun-metal, small size for supply to condenser, etc., with screw-down valve, and corrugated nozzle, screwed for £- in. pipe, with boss for lead joint . . each £260 £039 211 211A 211s Water Taps, gun-metal, £-in. bore, with corrugated nozzle and coupling for indiarubber tube, with boss screwed £ in. . . . . . . . . . . each £076 21lAs Water Tap, of gun-metal, with lever handle, one half turn, to allow flow or cut off, f-in. bore, screwed for f in. pipe . . . . . . . . . . . . each £043 CROSS STREET • HATTO^T GARDETST, E BAIRD &TATLOCK. (LOM)ON) LTD. BAIRDfcTAUOCK tuft* (lONDONH" 212 214 Water Taps, all of gun-metal, g-in. bore, New Pattern, with two small s.-n-w down side lead Taps, for high-pressure water, corrugated at nozzle for indiarubbrr tnlx- conn.-, tion to condensers, etc,, with boss screwed f in. thread for connection to supply . . «-.K h Water Taps, of gun-metal (Fig. 212), jj-in. bore with one srrrw-down stopo, k .it right or left hand, for indiarubber tube connection to condensers, etc., with boss screw, d il in. ........ i-arli Water Taps, of gun-metal, g-iu. bore, with two side plug stopcocks, for* indiarubber tube connection to condensers, etc., with boss screwed f in. The above side lead plug taps are only suitable for low pressure supply . . . . . . . . each £0 12 £080 £0 II O 215 216 Water Standard of gun-metal, with back nut and union for connection, with two small screw-down taps, J in. bore. Height from bench to nozzle of taps, 5 in. Water Standard, with three-way gun-metal water tap, the two side lead taps are suitably for supply to condensers, etc. Height from nozzle to bench top, 6 in. . . £0 17 6- £140 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &TATLOCK (LONDON) LTD. oc*u 217" 218s 220s 221s 222s 217 218 221 222 Water Taps, of gun-metal, f-in. bore, new pattern, with two screw-down side lead taps, all corrugated at nozzle, mounted on gun-metal standard, height from bench top to nozzle of tap 12 in., with |-in. back nut and union for connection .. each £1 8 Water Taps, of gun-metal, with screw-down valve, and corrugated nozzle, bore J-in., mounted on gun-metal standard, with J-in. back nut and union . . . . . . each £0 17 Water Tap, of gun-metal, f-in. with screw-down valve and corrugated nozzle, screwed to tap which can be easily removed, and replaced by metal filter pump, as shown in No. 221 each £0 5 Water Tap, as above, and metal filter pump combined, as devised by Dr. Martin, Lister Institute of Preventive Medicine. (a) With gauge . . . . . . each £2 17 (b) Without gauge . . . . . . „ £115 Water Taps, suitable for lecture table, with ground joint, so that when not in use it can be folded under the level of bench top, with right angle tail piece, and |-in. union for connection, so that the tap can be fitted over end of sink under bench top each £0 14 223s 223 Water Taps, of gun -metal, f-in. bore, suitable for use on lecture table, with ground joint so arranged that when not in use it can be folded under the level of bench top, fitted with f-in. boss for connection, height from joint to nozzle of tap 5] in. . . . . each £0 10 CROSS STREET • HATTCHSr GARDETST, E-C BAIRD &.WLOCK (LONDON) LTD. I 224s 225s 226s 224 226 Water Taps, of gun-metal, suitable for use on lecture table, with (-round joint n ,m.mg<-d that when not in use it can be folded under the level of the bench top with circular wh.-. I ,handi ' .. etc* Water Taps, similar to above, but nickel-plated Water Taps, of gun-metal, g-in. bore, with bend fixed by coupling screw, -,,, that lap .an be used either right or left hand, height from bench to outlet of no/./.le 5-' in with .'.-in back nut and union £0 10 £0 12 227 228 227s Water Taps, of gun-metal, with swan neck bend, screw-down valve, height of tap from bench top to outlet of nozzle, 10 in., with -J-in. back nut and union . . 228s Water Tap, of gun-metal, jj-in. bore, with bend fixed by coupling screw, height from bench to outlet of nozzle, n in., with two side plug stopcocks, with i-in. back nut and union for connection .. .. .. •• •• each £0 11 6 each £0 14 6 £100 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 45 BAIRD &TXTLOCK (LONDON) LTD. BRIRG&TMTLOCI«l-OI>|DOIN>LTi * Inside Measurements. 9 by 9 by 12 in. 12 „ 12 ,, 14 in. 15 „ 15 ,, 18 in. 20 „ 20 „ 24 in. 1'rice. with cxti.i . .1 £10 17 6 £12 0 0 £15 10 6 .£17 1 0 £19 11 0 £21 10 0 £27 12 0 £30 7 1 Co £0 7 6 Ci £0 10 6 C2 £0 15 0 C 3 £1 0 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &TATLOCK (LOM)ON) LTD. ftr, BAIKB& TATLtlCK Automatic Gas Regulator (Registered No. 536814) as fitted to Incubator. 311-314 Douduey's Cool Incubator, with our Improved Automatic Gas Regulator (Registered No. 536814). This Incubator is made of well-seasoned oak, with uralite panels, with an inner water-jacket of copper. It is fitted with double doors (inner of glass), and the inner chamber is carefully insulated by a jacket of slag wool. It is sent out complete, fitted with the new pattern gas regulator, ther- mometer, and burner, ready for connection to gas supply. These Incubators are sent out to regu- late at 22°C., but other higher temperatures may be obtained by the substitution of a capsule having the necessary boiling point. The capsules we can supply to suit any ordinary Incubator temperature, each suitable for a range of 4° C. 311s Size No. i. 312s „ No. 2. 313s „ No. 2A. 314* „ No. 3. Inside size of Chamber — Height, 12 in. ; width, 10 in. ,, ,, ,, 16 in. ; ,, 14 in. 20 in. ; „ 16 in. 36 in. ; „ 18 in. back to front, 10 in. ,, ,, 14 in. ,, „ 16 in. 18 in. INSTRUCTIONS FOR FITTING UP DOUDNEY'S COOL INCUBATOR. £750 £10 10 0 £14 10 0 £16 0 0 The incubator should, if possible, be placed in a room the temperature of which is a few degrees lower than the temperature the incubator is required to work at. Close the bottom tap on side of incubator, unscrew brass cap at top, and fill chamber with water until it flows out at open tube at other side of incubator. Connect gas supply to coupling B of regulator by metal composition pipe or indiarubber tube. This gas supply pipe should be provided with a tap. Turn on gas supply and light burner under incubator. When the required temperature is reached, the gas will be lowered by the expansion of the capsule C. temperature required is indicated on the thermometer, turn the disc D to the left until flame is just lowered. the expansion of capsule before the required temperature is reached, turn disc D to the right. The byepass screw F should now be adjusted so that the gas flame is further lowered until it is only about To provide for the regulating of the incubator in warm weather connect the tap E to water supply, and allow water to flow very gently through the chamber and out by the open tube at the side. During colder weather the water supply will be unnecessary. If it is required to remove the capsule C, open doors of incubator and push capsule towards side of incubator until the small stud is clear of plate-holder G, then slide out plate-holder G, when capsule will drop out. If gas is not lowered when the Should the flame be lowered by in. high. CROSS STREET • HATTCTN GARDETST, E- C i&* BAIRD &TATLOCK (LOMDON) LTD. 15s Incubators, all copper, double doors, the inner of glass, with stopcock and gauge, complete felt covering and stand. Size Inside Height „ Width „ Depth Price A 8' 8 8 65/- B 12 10 10 90/- C 16 M M 140/- D 20 in. i(> in. 1 6 in. 190/- C 16 M 14 110/- I) 20 in. 16 in. i(> in. 150 Any other si/.e or Form made to order. J15S Incubators, as above, but made in zinc, with copper bottom. Size A B Inside Height . . 8 12 „ Width . . 8 10 „ Depth .. 8 io Price 551- 75 /- Burners, Thermometers, and Mercury Gas Regulators extra. 161- Incubators, of copper, felt covered, with double doors, inner of glass, new pattern with our automatic gas' regulator (Registered No. 536814), and capsule to control temperature at }7°C., complete with thermometer, gas burner, etc.. ready for connecting to gas supply. Size A B C Inside Height . . 12 16 20 in. ,, Width . . io 14 i<> in. ,. - Depth . . io i I 16 i;i. Price £6 15 0 £850 £11 0 0 Sec No. 301 for instructions for fitting up Incubator and adjusting Regulator. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 65 ST. BAIRD &TATLOCK. (LONDON) LTD. 317 317s Opsonic Incubator, copper, with our new pattern Automatic Regulator (Registered No. 536814), adjusted for a temperature of 37° C., with twenty water-jacketed tubes for blood pipettes, and ten tubulures for carrying culture tubes. The automatic gas regulator is similar to that described under No. 301. Price with burner .. .. .. .. £4 15 0 318s Pipettes, for use with above, straight . . . . . . per doz. 8d. ; per gross £070 319s „ „ „ curved .. .. .. „ lid.; „ £0 10 0 320s Tubercle Bacilli, for making emulsion for opsonin testing, in tubes.. '. . each £0 5 0 321 Electric Signal Timing Clock. This instrument was originally designed as an automatic electric bell signal for timing the period of incubation of the blood tubes, in Dr. Freeman's opsonic incubator as used in Dr. Sir A. E. Wright's laboratories, at St. Mary's Hospital, W. The clock, can, however, be used for electrically noting periods of time from one minute, by multiples of one minute, to one hour, and as such can be arranged for physiological and other experimental work. The working of the apparatus is ac- complished by means of a metal plate which surrounds the clock, this plate having a series of sixty holes of equal distance apart corresponding to minutes in the clock. In the centre of these holes a metal rod is fixed, the other end of this rod passes through an insulating ring and projects inside Ihe clock face where it makes contact with the hour hand of the clock. A small metal plug inserted in the hole in the metal plate short circuits this and the metal rod, and thus signals the time when Ihe hand of the clock makes contact with that particular rod. The clock is of an American type CROSS STREET • HATTCTST GARDEN, E-C 66 6f best quality, and the battery a ivlial.lr dry one. The whole instnini.-iit i, ,-M.,,n,-lle,l whit,- ami silver, the numbers on the plugs ;ui|>riiv ll.llt.l. t IIOIII II,. Ml. ill ll.lll'l. 321" Price fitted with twenty pings, bell and battciy 322^ without bell or battery £220 12 0 0 For working this clock in conjunction with (lie opsonic incubator it m.u I"- desirable (or two workers to use the same timing clock with perhaps the same or two separate incubators. To meet this .1 ke\ U,.ir.l ..nlv i-, supplied, lilted with plu^s numbered i to 20, this is mounted on a woe d b.i-.e. t!:,- plnv. I , ,,,1; en.un. !:. 1 black. Ilie dilli Tence in colour will obviate any confusion in so usinj. the clock. 323s Price of keyboard and pings £0 7 6 vv 1 V BODY FULL SIZE Automatic Gas Regulator as fitted to Autoclaves Nos. .^.5. 32 S. $ \i and ; 1 1 . See instructions below. INSTRUCTIONS FOR FIXING AND WORKING AUTOCLAVES WITH AUTOMATIC GAS REGULATOR. The Autoclaves are sent out complete with the gas-regulating gauge (r.) in position. When fixing up place valve body (v) in seating after carefully cleaning both, fix lever (L) by -cicw r-in irj, and lastly put on weight (w), which is adjusted to allow valve to blow oft at pressure indicate) tiung from the corresponding marks. The gas inlet (A) must be connected to gas supply by means of rubber tubing. A second pic. taken from (B) to (c), which leads to the gas burner. The part (D) must then be turned round so as to set the red index pointer on front of gnu*.- temperature at which it is desired to work. The gauge will then regulate the gas supply to burner so as i keep interior of autoclave about this temperature. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &.TATLOCK (LONDON) LTD. 324 325 324s Incubator, Nuttall's, for use with microscope, of copper, felt covered, with thermo-regulator and burner, as figured ...... ..£45 325s Autoclaves, Chamberland's pattern, improved form of sterilising under steam pressure up to three atmospheres, heavy copper boilers, brazed joints, with gun-metal cover, and brass wire basket. Pressure gauge marked in Ibs. and also thermometric degrees, and fitted with arrangement so that the gas burners are automatically lowered when the required temperature is reached (see Diagram and Instructions on page 67). Sizes i, 2, and 3 are fitted with brass jackets ; Nos. 4 and 5 with sheet-iron jacket. No. .. .. •• .-I 2 3 4 5 Depth of copper pot inside . . 6J 9^ 13 17 21 in. Diameter ,, „ .. .. • • 4f /J 10 13?, i8J in. Price, complete with Gas Burners . . £9 5s. £12 £16 £20 £32 Above Autoclaves are made in oar own Factory, and thoroughly tested up to four atmospheres. 326s Autoclaves, Chamberland's pattern, similar to No. 325, but fitted with ordinary gauge marked in Ibs. and thermometric degrees, without the arrangement for adjusting the temperature, with brass lamp for burning paraffin oil. These Autoclaves are adapted for use where gas is not available. No. .... . . i j 3 4 5 Depth of copper pot inside . . 6J <).', 13 17 21 in. Diameter ,, „ . . --41 7\ 10 i ;', 18} in. Price, complete with suitable Lamp £9 10s. £1'2 15s. £17 £21 £33 10s. Above Autoclaves are all made in our own Factory, and thoroughly tested up to four atmospheres. 327s Autoclave Washers, of special asbestos and steam rubber, to suit Autoclaves Nos. 325-331. For Autoclaves, Size No. . . i 2 3 4 5 Price .. .. .. .. 2/- 4/- 6/6 9/- 15/6 each. CROSS STREET • HATTON GARDEN, E-C BAIRD &. TATLOCK. (LONDON ) LTD. ft 329 328s Autoclave, Chamberland's, for sterilising under steam pressure ; improved form with bracket arm and screw for raising top. By giving the wheel handle a few turns, the cover is raised sufficiently to clear top of autoclave, and can then be swung to one side and sup- ported in position by the bracket and vertical steel shaft. The autoclave is tested to tin -•••• atmospheres pressure, and is fitted with pressure gauge graduated in Ibs. pressure and thermometric degrees Centigrade. By a mechanical device the gauge <-an be adjusted so that when the required pressure is reached the burners are automatically lowered. The cover is of gun-metal and the boiler of heavy copper ; all joints brazed. It N mounted on mild steel jacket and fitted with a set of suitable star bunsen gas burners. ("oni| similar to Fig. 329, with safety valve, inner basket for sterilising, etc. No. Depth of copper vessel Diameter of copper vessel Price, complete • 3 • 13 . . 10 £17 4 17 '31 £22 5 _'i HI. : in. £34 10s. 329s Autoclave, Chamberland's, exactly as above but fitted with bunsen burners lor burning methylated spirit where gas is not available. In this autoclave the pressure gauge is oi the ordinary pattern graduated in Ibs. pressure and thermometric degrees No. .. .. .. .. .. • • 3 4 Depth of copper vessel .. • • 13 Diameter of copper vessel . . . . 10 Price, complete with lamp .. .. £18 £24 5 Ji in. £37 10*. n CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 69 BAIRD &. TATLOCK (LOTSIDON) LTD. 330 330s Autoclaves, Chamber-land's, exactly as No. 329, but adapted for heating with brass lamps for burning paraffin oil Price, complete with lamp No. 3 £18 331 4 £23 £35 10s. Autoclave, Chamberland's, for sterilising under steam-pressure, improved form with, arrangement for removing top by hand or foot. By pressing down the foot lever or handle on vertical shaft, the cover is raised sufficiently to clear top and can be swung to one side, the shaft supporting same in position. To place cover on top of Autoclave the movement is reversed. The Autoclave is tested to three atmospheres pressure, and is fitted with pressure gauge graduated in Ibs. pressure and thermometric degrees Centigrade. By a mechanical device the gauge can be adjusted so that when the required pressure is reached the burners are automatically lowered. The cover is of gun-metal, and the boiler of heavy copper, all joints brazed. It is mounted on mild steel jacket, and fitted with a set of suitable star gas burners. (The No. 3 size is fitted with brass jacket.) Complete, as figured, with safety valve and inner vessel for sterilising. No. ...... 3 4 5 Depth of copper vessel inside 13 in. 17 in. 21 in. Diameter of copper vessel inside 10 in. 13! in. i.Sj in. Price complete .. .. £18 10 0 £23 10 0 £36 332s Autoclave, Chamberland's, exactly as above, but fitted with brass lamp for burning paraffin oil where gas is not available. In this Autoclave the gauge is of the ordinary pattern graduated in Ibs. pressure and thermometric degrees Centigrade. No. .. 3 4 Depth of copper vessel .. 13111. 17 in. Diameter of copper vessel Price, complete with lamp 10 in. £19 10 0 £24 10 0 5 21 in. iNj in. £36 10 0 CROSS STREET • HATT>J GARDETST, E- C BAIRD & TATLOCK (LOM)ON) LTD. 333-334 335 Steam Digester or Autoclave for high pressure, with copper boiling vessel and cover of phosphor bronze, fitted with gas-pressure regulator, with automatic arrangement for lowering the gas burners when the required pressure is obtained. Prices, complete with burner : — Size of copper boiling vessel B333S To work at 8 atmospheres 334 20 8 by 4 in. £6 10 0 £770 8 by 6 in. £7 15 0 £9 15 0 10 by 8 in. £10 10 0 £19 10 0 Digester, Steam, as above, fitted with stirrer, adapted for high pressure. Size of copper boiling vessel . . 8 by 4 in. 8 by 6 in. 335^ To work at 8 atmospheres .. £880 £10 5 0 A335 20 £9 10 0 £12 50 £23 5 0 10 by 8 in. £13 10 0 Other sizes to order, up to 250 atmospheres. Prices on application. These Digesters are tested several atmospheres above working pressures. I CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &L IXTLOCK (LONDON) LTD. 336-337 337 (Section) 336s Steam Steriliser, Schimmelbusch's pattern, constructed to work at a steam pressure of 4 Ibs. per square inch, with pressure gauge graduated in Ibs. and thermometric degrees, and two containers (Fig. 338), with gun-metal cover and clamping screws, thermometer, gauge glass, stopcock, and condenser. The steriliser is encased in a stout japanned iron jacket, and is supplied with suitable bunsen burners or petroleum lamp. Price, complete with gas burners or petroleum lamp as required £17 1 337s Steam Steriliser, Schimmelbusch's pattern, to work at a pressure of 2 Ibs. per square inch, similar to above but without pressure gauge to work at atmospheric pressure, with double-walled copper vessel, inside size 19! by I3i in., to hold two containers (Fig. 338). . . . . . . . . . . . . . . Price complete £14 1 338 339 340 338s Containing Vessels for above, nickel-plated brass, height 9 in., diameter 13 in. each £1 339s „ „ ., ,, „ „ 4» in-, ,, 13 in- •• £1 340s ,, ,, „ ,, semi-circular, 9! by 13 by 6J in. „ £1 CROSS STRET • HATTOTST GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. 341 341s Autoclave, horizontal pattern, for sterilising under steam pressure up to three atmospheres pressure, heavy copper boilers, with brazed joints, gun-metal cover, with hinged bark so that the cover can be opened as shown in illustration. The autoclave is fitted with two movable shelves as shown and is mounted on heavy iron stand with burners and air screen. The autoclave is fitted with a gauge and automatic gas regulator, so that th<- is lowered when the required pressure is reached. The gauge is graduated to read in Ibs. and temperature in Centigrade degrees. Size Diameter Depth No. 2 7\ 9 3 10 13 3 iSJ in. 21 in. Price £17 0 0 £19 15 0 £26 10 0 £39 0 0 BAIRD &TATLOCK (LONDON) LTD. 342 (Section) 342 342s Autoclave, Schimmelbusch's pattern, of sheet copper, for sterilising tinder a steam pressure of 8 Ibs. per square inch, outer jacket of sheet iron, size of Container, 16 by 24 in., fitted with thermometer, gauge graduated to 10 Ibs. per square inch, and marked in degrees Fahrenheit. Water sight level, filling cup and draining taps, jacket for condensed steam. Paraffin heating lamp or Bunsen burners Please state if required for Gas or Oil. £18 5 0 CROSS STREET • HATTQN GARDETST, E-C 74 BAIRD &WLOCK (LONDON) LTD. 343 344-345 346 Steam Steriliser, made of hard rolled copper throughout, felt eoveied, with men heating surface and sheet-iron screen for burner, felt covered, with gauge, --(opt IH k. and cover. Size inside Inner vessel of copper, extra 20 by 8 in. £2 10 0 £0 .10 0 2(i by KI in. £35 0 £0 12 6 .'() by IJ ni t4 0 0 £0 15 6 - Steam Steriliser, Koch's, simple form, of hard rolled copper, felt covered, with co\vr, thennometer tubulure, water gauge and stopcock, on iron stand. Si//- insid'- . . 20 by 8 in. 20 by 10 in. -'" by I-' in. 20 by i<> in. £250 £2 15 0 £350 £4 15 0 Inner vessel of copper, extra £0 10 0 £0 12 6 £0 15 6 £150 :5S Steam Steriliser, zinc with copper bottom, felt covered, similar shape to alxnv. Size inside .. 20 by 8 in. 20 by 10 in. _•<> by 12 in. _•(> bv i<> in. Inner vessel of zinc, extra £1 12 £0 5 £1 17 £0 7 £2 5 £0 8 £3 10 £0 15 Steam Steriliser, same as Fig. 343, of hard rolled copper, fitted with suitable lamp for burning petroleum, giving smokeless Hanie, for use where gas is not available. Si/.e inside .. .. .. 20 by 8 in. _•<> by 10 in. jobs i Price, with lamp and screen .. £380 £430 £4 18 0 Inner vessels extra, see Figs. .550 and -,51. 7- Thermometers, engraved scale 0-200" C. for steam sterilisers, Noi. 34 j-j 19 cadi £026 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 349 350 351 349 (Section) 349s Steam Steriliser, automatic condensing pattern, square form, of copper, felt covered, with shelf in centre. DESCRIPTION. This Steriliser is rapid in action, water is poured into the reservoir (A) and percolates through (B) into the shallow generator (c), where it is immediately converted into steam, and rising through (D) into sterilising chamber (E). The excess of sleam escapes through jacket (F) and is condensed by the air, falling again into reservoir (A) and thence to generator (c). The Steriliser is thus automatic in action and will attain a steam temperature almost immediately the burner is lit. Size of chamber E Price Size No. i 20 by 10 by 10 in. £6 10 0 20 by 12 by iz in. £7 10 0 JO by 16 bv i') i;i. £9 15 0 350s Inner Vessels for Steam Sterilisers (Figs. 343-346), with cover, bottom perforated. Diameter . . 6J 8 10 14 in. A. Zinc . . 5/6 7/- 8/6 15/- B. Copper 10/- 12/6 15/6 25/- 351s Inner Vessels for Sterilisers, of galvanized iron wire, with cover. Diameter . . 6J 8 10 in. 7/6 8/9 13/6 352 352 (Section) Steam Steriliser, with automatic feed, in hard rolled copper, asbotos rov.-trd. mounted on galvanized iron stand. The supply of water from cistern is so arranged that tin- \\ in steriliser is maintained at a constant level. A. Size of steriliser, 20 by 10 by 10 in. . . B. ,, ,, 20 „ 12 ,, i^ in. . . C. 20 „ 16 ,., 10 in. £8 15 £9 15 £11 15 353 "^•M Steam Sterilisers, square, copper, tinned inside, covered asbestos, with two perforate movable trays, on stand, with tap and gauge. A. 20 by 10 by 10 in. . . B. 20 ., 12 '„ 12 in. . . C. 20 „ if) „ 16 in. £350 £3 15 0 £550 BAIRD &. TATLOCK (LONDON) LTD. 355 355s Steriliser, for surgical instruments, bandages, etc., with lamp. The special advantages of this apparatus are that it is entirely seamless, no part being soldered or riveted ; made in stout brass polished and nickel-plated. Stand and lamp pack inside steriliser. Size . . . . . . . . 8| by 4! bY - m- I3l by 6| by 3 in. Price . . . . 17/6 25 j- each. 356s Steriliser, same as Fig. 355, but, in addition, fitted with boxes for sterilising bandages and for use with gas. Size . . . . . . . . 8f by 4f by 2 in. 13! by 6| by 3 in. Price . . . . . . . 23/- 42 /- each. 357 358 357s Steriliser for Instruments, of enamelled iron, portable form with three trays, fitting into each other 358s Steriliser, for surgical instruments, bandages, etc. The steriliser is absolutely seamless and is made of stout brass nickel-plated. Size . . . . . . 2o£ by 12 by 4^ c/m. 33 \ by ill by 5 c/m. Price with lamp . . . . 17/6 23/6 £0 18 0 CROSS STREET • HATTOr>T GARDE TSf, E-C 78 BAIRD &TMXOCK (LONDON) LTD. 359-360 361-363 Electric Sterilisers, arranged for cither K.O-I.SO volt,. .»• m 22O, or J3O-ajO volt,. Prices of other voltages on application. 359* Steriliser, nickel-plated, fitted with loose tray and spring folding feet, 7 by 3 "... fOO watt u 16 6 " " •• M 'i by )! in., ii^n watt, £3 5 0 The above are arranged for temperature regulation. J61^ Steriliser, nickel-plated, 8 by 4 by 2| in. deep ; (,oo , onsumption wattJ t.. |0 Flexible Conl. pt-r y.nd £0 I »62S Steriliser, nickel-plated, 12 by 8 by 5 in. deep ; 1,000 a.i^umptimi watts t.S 0 Flexible Cord, |x-r y.ird £0 1 563^ Steriliser, nickel-plated, 20 by 8 by 5 in. deep ; 1,600 consumption watts t.» Flexible Cord, per yard t<> 364 365 Kettle, for electrical heating, it can be used to boil either a small or but care should be taken to sec that it is not allowed to run dry. Capacity Current used at no volts .. .. -•[ 3} Price .. .. .. .. 16/- 241- 366 quantity of water, I litre 5 ami*. 27/3 \Yhen ordering please state voltage of current available. Soxhletkettle, with carrier for 8 bottles for milk sterilising, adapted for heating by electricity . . £2 13 N.B. — When ordering please state current and voltaic. Can, for sterilised water, made of heavy brass, well nickelled, tinned inside. Capacity . . • • 5 10 J5 -» litres. Price 30/- 40/- 48/- 56/- 0 6 0 6 5 0 I 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS III BAIRD &TXTLOCK (LONDON) LTD. 367-368 369-A369 Hot Air Sterilisers, with double hot air jacket, and double jacketed doors as illustrated; one shelf removable. Perforated false bottom, air ventilators in top ; temperature controlled by our automatic gas regulator and capsule arranged to regulate at 150° C. Any other size made to order if desired. Size 367s Price, in copper 24 by 24 by 18 30 by 30 by 20 36 by 30 by 24 in. £16 16 0 £18 18 0 £23 10 0 368s Price, in mild steel £12 7 6 £13 10 0 £16 5 0 II 12 14 in. 7 10 12 in. q 10 12 in. £1 12 0 £220 £2 10 0 £0 11 6 £0 15 0 £0 16 0 369^- Hot Air Sterilisers, of sheet iron or copper, with double air jacket and ventilator at top. For sterilising at high temperature by means of hot air. Height of oven inside Depth inside "Width inside Prices in iron, with stand Price covered with asbestos, extra . . Thermometers extra. A369S Hot Air Sterilisers, as above, but made in copper throughout. Height inside .. .. .. 11 , 12 14 in. Depth inside . . . . . . 7 10 12 in. Width inside .. .. .. q. 10 12 HI. Price with stand . . . . £270 £390 £4140 Price covered with asbestos, extra .. £0 1 1 6 £0 15 0 £0 16 0 CROSS STREET • HATTOTST GARDEN, E-C 370 170s Hot Air Sterilisers, copper, covered with asbestos, on stand (single jacketed), with 2 shelves. A. 12 by 8 by 8 in. inside B. 1.1 by 12 by 8 in. inside £2 10 £3 3 371-372 Hot Air Steriliser, double walls, asbestos covered, 14 by 14 by 16 in. high, with perforated false bottom and movable shelf in centre, mounted on iron screen with set of three rose burners, complete. 71s Price in copper .. .. .. .. .. each £7 15 0 72- Price in mild steel £6*0 1 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. HOT AIR OUTLET M AIR INLET J O I AIR INLET. Showing direction of hot air. 373-374 Hot Air Steriliser, with special heating arrangement. The steriliser has triple walls, and is covered with asbestos on the outside, the gas burners being placed between the two outer walls, the air circulates as shown in the illustration, thereby preventing loss of heat and keeping a more uniform temperature inside than when heated only at bottom. In about twenty minutes a temperature of about i5o°C. can be reached and maintained. No. i 2 3 4 Height inside 12 16 16 24 in. Width inside IO 12 24 32 in. Back to front 8 12 16 20 in. 373s Price, in copper on stand £500 374s Price, in mild steel on stand £3 17 6 £626 £11 17 6 £16 17 6 £4 17 6 £826 £10 17 6 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &.1M1OCK (LOM)ON) LTD. 375-376 377 |!75S Hot Air Steriliser, copper, 16 by 16 by 20 in., with double walls, asbestos covered outsi.!.-. with two movable shelves, fitted with our registered pattern automatic regulator (No. 536814), to regulate at a temperature of 150^., or any requital tiMinxMut lire each £1.1 10 0 Other Sizes made to order. (See No. 301 for description and enlarged illustration of regulator.) 176s Hot Air Steriliser, copper, as above, but without automatic regulating capsule arrangement, with double walls, asbestos covered, 16 by 16 by 20 in. wide in--it> and lids, regulator and thermometer. Price, as figured, with bunsen burner, thermometer, and regulator . . . . . . . . . . . . . . each 388s Embedding Bath, as above, but fitted with automatic Electric regulator an on top are for drying slides, mounted on stand with screen. Prire, complete with ther- mometer and burner . . . . . . . . . . . . . . <-a<-h 395s Vacuum Paraffin Embedding Bath, «f copper, to work by hand pump. Size of chamber, 9 in. diameter by 6 in. deep inside, with stout fjlass cover and I.K. washer. Pruv, with thermometer and gas regulator . . . . . . . . . . each £4 12 6 £350 397 396T Vacuum Embedding Apparatus, Hearson's, heated by gas 397' Vacuum Embedding Apparatus, Hearson's, heated by electricity (\Yhen ordering, give voltage of supply.) each £4 16 0 £600 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE Cl 5MICALS BAIR.D &TATLOCK (LOM5ON) LTD. 398 399 398T Vacuum Embedding Apparatus, Hearson's, with air pump 399T Vacuum Embedding Apparatus, Hearson's, to work with petroleum lamp . . each £7 0 C £6 15 ( 400 401 400s Copper Bath, for sterilising Vaccines, with automatic capsule- regulator to maintain a uniform temperature of 56°C., with movable copper 'test tube stand for 12 tubes to be immersed in bath. Complete on stand as figured . . . . . . . . each £3 15 401s Copper Bath, for sterilising Vaccines, with movable inner stand for 12 tubes, fitted with lid and thermometer. Our Registered automatic regulator and burner adjusted for temperature of 56-6o°C. Price complete as figured . . . . . . each £315 CROSS STREET • HATTON GARDETST, E- C BAIRD &TATLOCK (LONDON) LTD. 403 402 404 1402s Copper Water Bath, designed by Dr. Houston, Metropolitan Water Board Laboratories for keeping sterile agar in liquid state at 42°C., ready for inoculation previous to pouring into petri dishes for cultivations, fitted with automatic capsule regulator, burner and stand, complete with thermometer and copper test tube stand for immersion in bath each •403* Porcelain Troughs, with twenty-four divisions for paraffin embedding '404 Paraffin Embedding Blocks, white glazed, with semicircular depressions, 2 in., ij in.,i J in. and £ in. diameter, for various size sections .. .. perdoz. 15/-; rarh £4 £0 £0 1 4 405 406 405s Copper Kettle with double jacket, for melting paraffin wax, etc. 406T Copper Trays, for sloping culture media tubes, numbered 1-20, and made so that the trays can be arranged in tiers, as shown . . each, 6/- ; per doz. Paraffin of various melting points, see Chemical Section at end of Catalogue. <-ach £076 £3 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &TATLOCK (LONDON) LTD. 407 409 407T " The Horsfall " Gas-Fired Destructor each £34 0 0 This type is especially suitable for burning rubbish which is not by itself combustible, such as condemned meat or fish, dead dogs, cats, or guinea pigs, plague infected rats, stools from infectious hospitals, etc. It is also very suitable for all cases where only occasional use is required, as it can be instantly put into operation by turning on and lighting the gas, and as readily put out of action when its work is completed. A supply of gas is required, the burners being provided with the destructor, and being fitted with special arrangements for regulating the air supply. By these means an intense heat can be secured in a few minutes, and, approximately, i cubic yard average animal refuse can be destroyed in four hours. 408' " Horsfall" Destructor, as above, but arranged for coke firing each £20 0 0 4094 Bacteriological Incubator, 9 by 7 by 7 in., specially designed for medical practitioners, fitted with movable tube stand for holding 3 by | in. tubes fcr Wassermann's Test, and with twelve brass receptacles numbered I to 12- At bottom of jacket for tubes for opsonic work. Made of copper, fitted in framed oak case with uralite panels. Controlled by our automatic capsule regulator at a temperature of 37°C. . . each £650 CROSS STREET • HATTOX GARDEN, E- C J*VL» BAIRD &WLOCK: (LONDON) LTD. APPARATUS. ETC., REQUIRED FOR WASHERMAN N s II s | 410' Antigen (Alcoholic Extract of Liver) ,,l,ial i,,, examination oi . Mmtn • • .. ,. 5 M • • •• in , . ... li £04* £076 L" || 0 41 r Amboceptor (Rabbit's Blood for Sheep's Corpuscles), s,,,,,,|,,.,l m t,,v,I,,,-s «,,|, three sheets, each sheet containing sufficient for lbdoM».. "„ i, £006 412- Complement (Blood of Freshly Killed Guinea Plft). , The* ,„,„, u- ,„,. and OB 413' Red Corpuscles of Sheep's Blood, ,0% suspension. . 2^8? bjV 416 \ 415 414 414s Test Tube Rack, labelled Complement, Antigen, Corpuscles, and Amboceptor, for 4 tulxs 3 by I in. . . each '415s Test Tube Rack, to hold 24 tubes, 3 by J in. in one row, labelled i to .24 416" Test Tube Rack, two tiers to hold tubes, 3 by J in., and numbered A. Stand. A, i, xA, z, 2.\, 3, .}A, up to I4A. B. „ 15, isA, 16, i6A, 17, i;A, tip to 24A. . . 417 Pipettes, i c.c. graduated in 100 divisions ; 10 c.c. 100 each, lOd. ; per doz. .. I/- 418 Pipettes, o.i c.c. in 100 divisions, with bulb at top and I. R. tubing on end. Each 1/3 419T Automatic Puncturing Apparatus (Dr. Laker) 420 Hypodermic Syringe, i c.c. " Record " with steel needles in metal case 421s Incubators. (See No. 294 for prices and description) adjusted for 3;°C or 55°C 422s Incubator. (See No. 409). 423 Test Tubes, 3 by | in. boxes, best quality for bacteriological purposes, per doz. 3d. ; per gross 424 Cylindrical Test Glasses, 16 oz., for holding pipettes in antiseptic solution each £086 £096 £086 £086 £096 £011 6 £0 14 0 £046 £076 £029 £009 I ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 428 429 430 A430 431 432 each 427 Gas Regulator, Page's, unfilled 428 Gas Regulator, Reichert's, filled with mercury 429 Gas Regulator, Reichert-Muencke, improved form, with stopcock to byepass, filled with mercury . . . . . . . . . . . . . . . . each 430 Gas Regulator, Bunsen-Kemp, unfilled . . . . . . . . ,, A430 Gas Regulator, mercury-toluol, as described in Findlay's " Practical Physical Chemistry." Price, unfilled . . . . . . . . . . . . . . each 431 Novy's New Thermo -Regulator. Size of cylinder, E, 15 by 120 mm. This is especially useful for regulating the temperature of a Hofmann water bath, or of a small incubator such as Nuttall's. Price unfilled . . . . . . . . . . each The diagram illustrates the construction of the regulator. Part A is provided with two lateral tubes which have a ground internal surface. Part B is ground to fit the preceding. It is provided with an opening through which the gas passes into the interior. The lower portion of B, opposite the outflow tube, is ground on the inside, and has a small opening one millimetre in diameter. The neck above is likewise ground internally. The lower portion of the tube B when placed in position inside of part A , should come within one or two millimetres of the bottom of the cup. In this case the first drop of mercury, as it issues from below, shuts off the outflow of gas. The upper part of part C is solid, whereas the lower portion is hollow. The lower portion of C is ground to fit exactly the corresponding part in B. The upper portion of C is a ground stopper fitting into B. The manipulation of the thermo-regulator is very simple. The gas enters through the upper lateral tube. If it is desired to diminish the inflow of gas. this can be done by turning B. By turning part C, the minimum outflow of gas can be regulated at will. To fill regulator, close the upper side tube by the ground tube, exhaust bulb by lower side tube, invert regulator and connect upper side tube to a supply of toluol, turn ground tube and allow toluol to enter until the bulb is filled. Fill mercury into bulb and tube until it appears as on sketch. 432 Novy's New Mercury -Toluol Thermo -Regulator, with glass stopcock for adjusting the level in mercury column. Size of cylinder E, 15 by 120 mm. This is especially useful for regulating the temperature of a Hofmann water bath, or of a, small incubator such as Nuttall's. Price unfilled . . . . . . . . . . . . each £0 1 9 £050 £070 £076 £060 £0 10 6 £0 12 CROSS STREET • HATTON GARDETST, ^^^-" ^~-._-~ Sr, BAIRD &TATLOCK: (LONDON) LTD. 433 434 435 437 33s Gas Regulator, Bi-metallic, as devised by Dr. Roux for accurately adjusting tlu- t<-mj ture of Ovens, Sterilisers, etc. No. .. Length Diameter of tube B i 15 20 £1 17 0 2 25 32 £280 40 centimetres. 32 millimetres. £2 19 34s Gas Regulator, Bi-metallic as above but U shape, and mounted on iron plate for fixing to wall or oven. As used in the Pasteur Institute, Paris. ABC Size of gas inlet C 5 8 12 millimeti. Price ..£400 £6 17 0 £7 17 6 fa, h. 15 Gas Regulator, spiral form, devised by Dr. Lowry, for maintaining an exact constant temperature in water baths, etc. The spiral is filled with Xylol or Toluol, and the bend at bottom of spiral and upright capillary tube is rilled with mercury. The gas enters by tube A and passes out to burner by tube B. The stopcock F serves for a fine adjustment of the byepass to tube B. Size of spiral, 8 in. by 3 in. .. .. .. .. price unfilled, radi £096 $6 Regulator, as above, but without stopcock and H piece, fitted with platinum wire in bulb for electrical regulating . . . . each £096 V7 Regulator, as above, by Dr. Lowry, but bulb form. Price with byquv* sti>|x-o»-k as F on Fig. 435 , . . . . . • • • • price unfilled, each £076 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &TATLOCK (LONDON) LTD. 438 440-441 438 Baskets, iron wire, tinned, without joint at sides A. 6f by 4 by 2f in. inside B. 5l by 3i by 3f in. „ C. 6 by 6 by 6 in. ,, 442 each, 2/- ; per doz. £130 £130 £1 14 0 Anv other size made to order. 439 Baskets of Tinned Copper wire (Fig. 438), specially recommended for use with dangerous cultures, the baskets being thoroughly well made, and free from small sharp points. A. Size 6|- by 4 by 2.\ in inside . . . . Price each, 2/6 ; per doz. £186 B. „ 6 by 6 by 6 in. ,, . . „ ,, 2/3 ; „ £186 C. „ 5t by 3f by 3f in. „ .. .. „ „ 2/6; „ £186 440 Boxes for sterilising pipettes, 12 by 3 by 3 in. Iron Copper 441 Boxes for holding glass plates. Size of plates A. Iron B. Copper each £036 £060 • • 4i by 3* in. each 3/- 4/6 442 Baskets for test tubes, with handle to fold down, J in. mesh. For . . . . . . . . 36 72 A. Galvanized iron . . . . 4/- 4/6 B. Copper .. .. 7/- 7/6 6-J- by 4f in. 3/6 5/6 144 tubes. 5/- each. 9/6,, 443 443 Iron Case for sterilising instruments and glass plates, 6 by 4! by 2 in., with inside tray, each £086 CROSS STREET • HATTON GARDETST, E- C It 444 6 i44 Copper Boxes, with lifter for sterilising Petri dishes. Size 10 bv 4 1 i. 445 Copper Boxes, with lifter, simi,ar to Fig. 444, for sterilising 446 Sterling Box, of copper, circuit with hinged doors and shelves for' ...... ,„„ Mx 447 Sterilising Box, of copper, as above, but square form £0 16 0 £0 15 • 448 449 448 Copper Boxes for sterilising pipettes. Size, 15 by 2] in. diam. eacli 449 Apparatus for the Sterilisation of Filtered Gelatine, used in subriitiiiu-ous mj, , ti,.n. devised by Mr. Gardner, London Hospital, with stopcocks . . ,..„!, £0 (See description, British Medical Journal, Oct. 26th, IQOI.) i50 Ehrlich's Apparatus for Drying Blood Films, with burner and condenser £1 £046 76 rl BAIRD ^T^TLOCK (LONDON) LTD. 451 453 454 452 451s Animal Balance, to weigh up to 20 kilos, with stout copper pan 25 centimetres long by 22 by 22 centimetres . . . . . . . . . . . . . • each £2 7 452s Animal Balance, suitable for guinea-pigs, rats, mice, etc., to weigh 10 grammes to i kilo, with copper pan . . . . . . . . . . . . . . each £015 453s Apparatus of Copper, Brazed Joints, for Heating Cultures to separate spore-bearing micro-organisms, by Professor C. Balfour Stewart. Price, on stand, but without ther- mometer or condensation tube . . . . . . . . . . . . each (Extract from CentralUatt fur Bacteriologie, March, 1900.) " Those who have occasion to work with spore-bearing micro-organisms must often have felt the want of an apparatus which would keep at a constant temperature of between 70° C. and 80° C. " An application of Meyer's hot air bath such as is used in chemical laboratories suggested itself as being most applicable to the purpose ; several of these were made and are now kept in everyday use in this laboratory. They maintain a constant temperature of 80° C. without any attention, and are always ready for placing tube cultures in, and, what is more important, the cultures may be left without any fear of their becoming heated above 80° C. " The apparatus is similar in construction to Meyer's hot air bath, except that it is larger than those generally used and has no outlet from the bottom of the inner chamber. " The inner chamber is 18 cm. deep and g cm. in diameter, and will take seven or eight tubes ; it is advisable to have a condensation tube of i metre in height. (1.5 metre is most suitable.) " In use. — A small quantity of pure benzole B.P. 80° C. is poured into the outer jacket through the hole for the condensation tube and the tube is reinserted. A small flame below will keep the benzole boiling, and as the vapour condenses in the condensation tube and runs back, very little is lost. " Thp inner chamber is filled to about one-third of its depth with water at 80° C., the water retains its heat when the lid is removed, and acts as a good conductor of heat to the culture tubes when they are placed in it. If water is not put in the inner chamber the heated air escapes when the lid is removed and it takes a long time for the culture tubes to become heated, whereas, if water is in the inner chamber and the culture tubes put in when the thermometer registers 80° C., it is found that there is only a fall of 10° to 15° C. and the thermometer rises to 70° C. in a few minutes. " The tubes are left in for 15 to 20 minutes after the thermometer has risen again to 70° C., so during that time they will have been kept at between 70° C. and 80° C., and for most of the time over 75° C." £1 16 454 Gas Burner for Incubators, with small luminous pointed flame and mica cylinder. A. Without stopcock . . B. With stopcock . . .... each £0 £0 CROSS STREET • HATTCTNT GARDEN, E-C 98 .- . 455 155 Gas Burner for Incubators, on stand to raise or lower, stopcock to each ict and mi. .1 chimney i 6/6 4 10/6 16/- 21 / t56 Extra mica for chimneys for above eavli. 1/1 ; perdoz. £0 12 0 457 458 Ring Burners. Inside diameter of ring . . . . . . 3 4 57 With stopcock and boss to fix to upright. Price 6/- 6/6 58 With bosshead but without stopcock. Price 4/9 5/6 459 6f in 9/- ea,-h. 59 Argand Burner, with stopcock on broad base, with pale blue glass chimney and shade, for microscope work .. .. .. .. .. .. .. »-ai h £0 13 6 59A Extra glass chimneys, pale blue . per doz. £060 iO Incandescent Burner, with byepass, on broad base, with chimney and shade, and OIK mantle, similar pattern to Fig. 459 . . . • each £0 12 6 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS lit, 99 BAIRD & TATLOCK (LONDON) LTD. 461 462 463 461T Microscope Lamp, Dr. Lassar's, for gas, on adjustable stand 464 each £1 15 462' Microscope Lamp, Dr. Lassar's, for petroleum 463' " Nernst " Electric Lamp (new form), specially designed and patented by J. E. Barnard, Esq., F.R.M.S. This lamp is designed to give an evenly illuminated field in the microscope, without giving an image of the incandescent film, which is common with every other form of electric microscope lamp. This is effected by the light from the incandescent filament falling upon an optically worked slab of opal glass fixed at an angle of 45° to the axis of the filament. The light so obtained resembles white-cloud illumination, and the bull's eye condenser, which is indispensable with ordinary lamp illumination, becomes unnecessary. The lamp is fixed on a swivel, and can be placed at any angle, and can be raised and lowered at will ; provision is also made for taking tinted glass light filters. The J-ampere lamp supplied gives more than sufficient light for a ^,-in. oil immersion lens. The current consumed by the " Nernst " lamp is 50 per cent, less than with the ordinary incan- descent lamp. The lamp was originally designed by the inventor for the Laboratories of the Lister Institute of Preventive Medicine, Chelsea, and it has also met with much favour in other laboratories. Intend- ing purchasers, when ordering, must give the voltage of their current, and whether cylindrical or forked wall plugs are to be supplied. METHOD OF USING THE LAMP. If the microscope is used in the vertical position, the flat top of the lamp should be tilted until it is parallel with the stage of the microscope, at the same time the lamp should be brought fairly close to the instrument. If the microscope is inclined, the top reflecting surface of the lamp should be tilted to bring it to the same angle as the stage of the instrument. Price of the lamp, for use with current of 150 to' 200 volts only . . each £2 0 464s Microscope Lamp, with small incandescent mantle, glass globe, and metal chimney as devised by Dr. Paine ; mounted on metal sole with control tap . . . . each £0 5 CROSS STREET • HATTO1ST GARDEN, E-C BAIRD &. WLOCK (LOM)ON) LTD. 465 4.,s >5S Microscope Lamp, adapted to take a small metallic filament electric lamp, with he.i\ \ base, and universally adjustable joint, parabolic mirror and lamp .. .. i-.u-h £110 j»6T Swift's Nelson -Dallinger Microscope Lamp, with improved mechanical arrangements for rapidly and accurately adjusting the flame vertically and horizontally. The lamp slides on a square pillar, and is clamped to about the required height ; e\a< t adjustment is then made, vertically by rack and transversely by a quick-acting screw. A HeiM-heliaii condenser is fitted to the base of the burner, with movements which permit it to be pla in any position and inclination, provided with semicircular groove in front for receiving coloured screens. Either the flat or edge of the flame may be used. Large enamelled oil container and metal chimney with heat conductor . . . . r.i' h 14 4 0 I»7T Ditto, without the mechanical, horizontal, and vertical adjustments .. .. .. £2 10 0 I»8T Swift's Microscope Lamp, for oil, with peaked shade .. £0 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD & TXTLOCK (LOM)ON) LTD. f>t>Of£SSOR D* R IfOCH'S Ofr/C/AL. INJECTION SYff//VG£ 469 470 469 Thermometers for Incubators, milk glass scale. Range . . . . . . o° to 100° C. Length of scale . . . . 4 Length of stem . . . . io| Total length . . . . . . 15 Price .. .. .. 3/6 471 50° to 100° C. 4 IOJ 15 3/6 o° to 50° C. 4 in. loi in. 15 in. 3/6 470 Thermometer, bent form, for Incubators, milk glass scale, o° to 50° C., in single degrees, each 471 Hypodermic Syringe, Koch's, in leather case, with steel needles. A. i cubic centimetre capacity. . . . . . . . . . . . e^ch B. 2 „ . . C. 5 ,. „ .... .... D. 10 472 472 Hypodermic Syringe, with asbestos pistons, suitable for sterilising, two needles, two glass barrels, three asbestos pistons, in case. Capacity . . . . i c.c. 2 c.c. 5 c.c. 10 c.c. Price .. .. 4/- 5/6 7/- 8/- each. £0 £0 £0 £0 CROSS STREET • HATTCTNT GARDEK, E-C rziia^-" ' ft BAIRD &TATLOCK. (LONDON) LTD. 473 473' Hypodermic Syringes, Roux's pattern, Collin's make, with itidiuniblx-r piston*, plunger graduated on stem with two steel needles in metal ea- Capacity Price Fittings for above. 474T Glass Barrels Price 475' I.R. Washers .. 476' I.R. Pistons 477' Steel Needles . . 478' Platinum Indium Needles can be supplied to fit above syringes, prices v.iuablt , according to the market fluctuations of the price of platinum. t C.C. 10/- 2 C.C. 12/- 5 c.c. 15/- 10. 18/- 20 C.C 25/- each. t C.C. 6d. 2 C.C. 6d. 5 c.c. 9d. M C.C. 9d. 20 c.c I/- each. 4d. 4d. 4d. 4d. . 4<1. per pair. 5d. 5d. 8d, Id. 8d. each. 1/9 1/9 1/9 1/9 1/9 ,. 479 479 Hypodermic Syringes. " Record," with metal piston ground to fit, graduated glass barrel, and two steel needles in metal case. 10 C.C 20 C.C. Capacity . . i c.c. Price 7/6 480 Extra needles . . 6d. 2 C.C. 8/6 6d. 5 c.c. 6d. I4/- 9d. 17/6 each. 9d. „ 8/- per doi. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &TATLOCK (LONDON) LTD. 481 481 Syringe for Injection, new " metaline " pattern, glass barrel graduated with metal top and nozzle soldered en glass, the plunger is of metal ground to fit barrel, each syringe is supplied with two needles in protecting sheath and metal case with rack. Capacity . . ... . . . . 5 c.c. 10 c.c. 20 c.c. Price .. .. 12/- 14/- 17/6 each. 482 482 Syringe, Aseptic Serum, all metal, with metal plunger, two needles, and connecting tube, in metal case. Capacity . . i c.c. 2 c.c. Price 5 /- 6j- 5 c.c. 10/- 10 c.c. 12/6 20 C.C. 14/- each. 483 483 Injection Syringe, capacity 50 grammes, with three nozzles with taps, all nickel-plated £0 15 0 CROSS STREET • HATTTST GARDETST, E- C 104- BAIRD • i in. 487 87s Apparatus for the Intravenous Injection of "606 " (Salvarsan, or Neosalvarsanl, as devised by Drs. Mclntosh, Fildes, and Dearden of the Bacteriological Labor.it. n\. London Hospital. Price, complete in Leather case, with thermometer, etc. . . r.icli Spare Parts — A. Thermometer, Graduated 60° to 160° C. . . B. I.R. Bellows C. I.R. Tube, J-in. .. .. .. .. .. . . PIT ft. I >. Needles . . . . . . . . . . . . . . . . per do/ E. Salvarsan " 606 " Ehrlich's . . . . . . . . pt'r tube F. Neosalvarsan . . . . . . . . . . .... DIRECTIONS FOR USE. In the following directions it is presumed that proper facilities are available for the sterilisation of the paratus. In the case of the glass bottle dry heat is preferable ; boiling is satisfactory for the rubber cork and tubes, also for the metal box. K2 5 0 £0 £0 £0 £0 £0 10 £0 6 BAIRJD &TXTLOCK (LONDON) LTD. The needles should be sterilised in olive oil by heating them to 140° C. in one of the test tubes plugged with wool. Before being heated in oil, the needles, if wet with water, must be rinsed in spirit, and great care must be taken that the fine bore is not obstructed by blood or any other matter. The rubber pump requires no sterilisation. Remove the glass stopper of the bottle and shake in the contents of a capsule of Salvarsan (0.6 grammes). Agitate the bottle so as to incorporate the powder with the glass beads. Fill the bottle with sterile saline solution prepared from freshly distilled water and pure sodium chloride. Replace the cork and shake thoroughly. Stand the bottle in hot water to hasten solution and to warm it. Shake occasionally. The solution should feel luke warm to the hand at 'the time of injection. Boil the Rubber Cork and its appendages for 10 minutes and then, after draining, place it in the sterile metal box. Having prepared the bottle of 15% Sodium Hydrate solution, and having sterilised the needles, the apparatus may be packed for transport and use within a couple of hours. The needles may be carried with their wires in situ in one of the test tubes, the points being directed towards the cork. At the bedside, remove the glass stopper from the bottle and add drops of Soda until the precipitate, which immediately forms, is just re-dissolved. This will require about 23 drops of 15°,, Soda Solution for 0.6 grammes • of Salvarsan. Care must be taken that the fluid is alkaline to litmus paper, since if too little soda is added, solution of the precipitate will occur owing to the original acidity of the Salvarsan. Acid solutions are highly toxic. " Screw " the rubber stopper (c) firmly into the bottle containing the solution of " 606." Insert the two filters (D and G), lightly plugged with wool, and attach the pump (F). Close the clip (E), and put a clip (N) en the tube leading to the needle. Give two or three pumps, and by momentarily releasing the clip (N) expel the air from the tubes. Attach the needle to the holder and again expel the air and oil by momentarily releasing the clip (N). Next, keeping the clip (N) in position, open the clip (E) for a few moments to relieve pressure in the bottle. Attach the bottle to the bedclothes by means of the collar and spike, so that it hangs on the side of the bed at a lower level than the patient's arm. A tourniquet having been placed on the arm, so that the veins stand out, sterilise the skin with Ether from the bottle and after again making certain that the needle is filled with solution to the tip, push the needle into a vein with the bevel down. Release the clip (N) entirely. The pressure in the vein will cause the blood to appear at the window (L). The needle must then lie in the vein. Next fasten the needle in position by laying a strip of adhesive plaster across the wings of the holder (M), these wings having been arranged to lie flat on the arm when the bevel of the needle is down. The strapping may conveniently be applied to the skin on one side before the needle is inserted and afterwards carried across to the other side. Release the tourniquet and give three or four pump?, and the blood will soon be seen to be washed from the window (L). and the injection will proceed without any trouble other than four or five applica- tions of the pump. Do not apply much pressure. Three hundred cc. are introduced in from six to nine minutes. At the end, re-apply the clip (N), entirely remove the clip (E), and press the air out of the bulb of the pump. Then release the clip (N) and the blood will syphon from the vein into the window (L). Re-apply (N) and with- draw the needle. Press upon the puncture and hold the arm in a vertical position for a moment or two. No dressing is applied, but the arm is wrapped in a clean towel and flexion of the forearm is not allowed for one hour. The success of a vene-puncture depends largely upon the condition of the vein and the position of the light by which the operation is performed. This must be held at right angles to the line of the vein and low down to give greater relief. It is also necessary to obtain a maximum prominence and distension of the vein to facilitate entry and to force the blood to appear readily at the window. Engorgement of the veins cannot be obtained readily by a circular application of a bandage. The best method is as follows : pass a piece of three inch bandage behind the arm and bring the two ends to the front : then, pulling very tightly, cross and reverse the ends, and carry them round again to meet on the outer side of the limb. Here tie a bow. In order to avoid pinching the skin under the point of reversal, place a " swab " between the knot and the skin. The veins can be made still more prominent by repeated clenching of the fist and by rubbing with Ether during the process of sterilisation. The state of the rubber tubing should be noted periodically. It is most apt to perish at the points at which the retaining wires are applied. 488 489 488 Mice Glasses, size about 8 by 6 in., with wire cover and bayonet joint 489 Mice Glasses, of clear glass, with wire gauze cap, weighted with lead. Height Diameter Price 8 in. 4 in. 2/6 each £066 Sin. 6 in. 3/6 CROSS STREET • HATTCTM GARDETST, E- C lOfi BAIRD &WLOCK (LONDON) LTD. 491 492 490 Glass Benches, for arranging glass plates and slides in tiers in damp dKunI,,,,. ,„-, , !„/. £036 491 Glass Benches, for same purpose, in one piece . . pe,. ,j07 £040 492 Copper Stands, riveted, for supporting plates and slides . . tn < ,, 495 497 493 Tripod Levelling Stand, of polished hard wood, with brass adjusting M-IVWS plate, spirit level and basin, as illustrated, extra, see Nos. 494 and 495) . . each £076 494 Glass Plate, for tripod stand, 12 by 12 by g in., polished edges 495 Circular Level, for tripod stand 496 Circular Level, for tripod stand, i in. diani. 497 Test Tube Stand, of copper, for immersion in water bath, with holes nuiui A. Diameter, 5 in. B. „ j\ in. £030 £056 £0 1 0 £030 £040 .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 107 BAIRD &L TATLOCK (LONDON) LTD. 2 in. 498 500 501 502 498- Indiarubber Caps, for tubes, flasks, etc., of best quality rubber. Diameter .. \ f \ \ I ij ij li if Per doz. .. 8d. 9d. lOd. lOd. I/- 1/2 1/4 1/8 2/6 499- Indiarubber Test Tube Caps, black, for fin. tubes, with plain rim, per doz. 8d. ; per gross £076 500 Indiarubber Caps, black, tall shape, for test tubes, etc. per doz., I/- ; per gross £011 0 501s Indiarubber Caps, suitable for use with serum bottles of 10 and 20 c.c. capacity. The caps are made so that they fit tightly on the neck, and so render the use of an indiarubber stopper and capping unnecessary . . . . . . per doz., 2/- ; per gross £1 3 502 Potato Borer, for cutting sections of potatoes each £023 503 503 Yeast Flasks. Capacity . . Price 504 505 506 . . 75 c.c. per doz. 4/- 504 Flasks for cultivation of Yeast, Friedenreich's pattern, with ground-on caps. Capacity . . . . . . . . 50 c.c. Each .. .. .. 9d. Per doz. . . . . . . 8/6 125 c.c. IOO C.C. lid. 10/6 505 Flasks for Yeast Cultivation, etc., Hansen's, with ground-on cap and side tube. Capacity . . . . . . . . 25 c.c. 50 c.c. 100 c.c. Price .. .. .. per doz. 9/- 10/6 12/6 506 Copper Stand, for needles, etc. . . each I/- ; per doz. £0 11 6 CROSS STREET • HATTOK GARDETST, E'C BAIRD &.TKTLOCK (LONDON) LTD. 5*07 507s Outfit for carrying Anthrax Specimens, per 1K)st, as approved l,y H...nd ..i Agriculture and Fisheries also by Post Office Authorities, consisting ot j-li<.lrd \VCM«! Him k with Cover Cardboard Cover with Printed Address, Sterilised tube with Swab. ( Mi, !,,., „,„• Price 508s Platinum Wire Loop, in Aluminium holder 509s Spirit Lamp, with brass Wick-holder 510s Steel Forceps, 5-inch perdoz.5/>; per gross £2 15 0 # .... 1. £038 £0 1 .* £0 1 8 OUTFIT FOR CARRYING ANTHRAX SPECIMENS. THIS OUTFIT IS INTENDED TO BE USED IN THE FOLLOWING WAY : - (1) It is to be noted that the tubes containing the swabs have Ix-rii sterilised, ami that tliry slmuM not («• opened until immediately before use, that the blood should be collected quickly on the swab, ami tin- returned immediately to the tube, which should be corked tightly. It is advisable nut to lay tin- tnln- down ,m any object while it is open during the process of impregnating the swab. otherwise it may !»•• mm- t> contaminated. (2) In the case of an animal which is suspected to have died of anthrax, the ear should !»• amputated or partially amputated close to the base, or a small incision should be made into one nf the superficial and pcriphcr.il I'll Kid vessels. (>,) The cork to which the rod containing the swab is attached should l>e quickly taken trom the tube. Hit swab should be soaked in the blood which has collected at the site of the incision, iiml immediately returned to the tube. (4) In the case of a pig or horse it will be better to rub the swab on the cut surface nl a superficial lymphatic gland, such as the submaxillary. (5) With blood from the incision or with material from the lymphatic gland, as the case may be, stn.-.ir* K £2 £2 £1 14 0 514 518 514 Diagnosis Outfit Case, as above in wood block cases for post per doz. 2/9 ; per gross Separate Fittings for Nos. 511 to 514. 515 Glass Tubes 516 Nickel Probes 517 Tin Cases . . . . . . . . ..'..• A517 Wood Block Cases with cover and clip 518 " Typhoid " Sample Case, wooden block with cover and metal clip, carrying glass tube with tin spoon fitted into cork, and tin case to hold tube . . . . per doz. £1 10 0 £0 6 £0 10 £1 4 £1 0 £060 CROSS STREET • HATTCTrSr GARDETST, E- C no jgpr BAIRD fcTATLQCK. (LONDON) LTD. 'OTUM, ] I ^t. 519-524 Sputum Diagnosis Outfit, consisting of glass bottle specially drsiK,,r,l f..r , • irmne the r and cup- and m " Price complete with glass stoppered bottle (Registered X,,. 5,m«,). per doz. 6/- ; per gross £3 10 0 Price, complete with corked bottle ( ) 4/9. Prices of Separate Fittings for Nos. 519 and 520. >21 Sputum Bottles, stoppered . . . . per doz. 3/- • >22 Sputum Bottles, corked >23 Wood Block Cases )24 Manila Covers , « qd £1 15 0 U 0 0 tl 7 0 £086 525 ]>25 Sedgwick -Tucker Aerobioscope (I <.i,h £0 1 6 i 528 526-527 530 531 532 533 26 Roux's Potato Tubes, Size above constriction 7 by i in. per doz. 3/- ; per gross £1 15 0 27 Roux's Potato Tubes, Size above constriction 6 by J in. „ 2/3 ; £160 28 Buchner's Tubes, Size above constriction, 8 by I in., without inside tubes or I.R. corks each 4d. ; per doz. 3/9 ; per gross £240 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICAL 111 BAIRD &TATLOCK (LONDON) LTD. 529 Buchner's Tubes, Size above constriction, 10 by ij-in., without inside tubes or I.R. corks each 6d. ; per doz. £059 530 Bulloch's Tubes, total length, 8 by J-in., below constriction, 6 in. for sealing off permanent Cultures in formalin . . . . . . . . . . each 3d. ; per doz. £029 531 Serpent Tubes, as designed by Dr. T. A. Starkey, for the isolation of Typhoid and Colon Bacilli from drinking waters, etc. . . . . . . . . . . each £016 (See American Journal of the medical sciences, July, 1906.) 532 Small Thermostat, for use in Widal's reaction with sterilised cultures, as devised by Prof. George Dreyer . . . . . . . . . . . . . . each £050 (JSZP. Journal of Pathology and Bacteriology. Vol. XIII., 1909.) 533 Typhoid Tubes for Widal's blood test .. .. .. per dcz., 3d. ; per gross £026 534 534 Typhoid Tubes for Widal's blood test, bent form per doz. 3|d. ; per gross DIRECTIONS FOR FILLING CAPSULES WITH BLOOD FOR SERUM DIAGNOSIS, as arranged by Sir David Semple, Pasteur Institute, Kasauli. (1) Sterilise the finger with carbolic lotion and dry. (2) Sterilise the pricker in the flame of a match or spirit lamp. The best improvised pricker is a " J " pen with one leg broken off. (3) Break ofi the tips of limbs (A) and (B) of the capsule. (4) Apply the point of the pricker to the pulp of the finger and drive in with a good sharp jerk : done in this way the pain is very trifling. The prick should be a bold one, so as to get a free flow of blood. (5) Apply the end (B) to the drop of blood, keeping the bulb of the capsule below the prick in the finger ; the flow of blood can be encouraged by wrapping a handkerchief tightly round the finger from base to tip. (6) When the bulb of the capsule is full, pass the limb (A) two or three times lightly through a flame, seal (A) immediately ; the blood will then be withdrawn from the end (B), and that end can be sealed. It is useless ' to try to seal the end (B), unless the blood has been withdrawn in the way mentioned. 535 535 Pasteur's Test Tubes, 6 by f in., with ground-on cap 536 Pasteur's Flasks, with ground cap. Capacity . . . . . . . . 50 c.c. 536 Price lOd. 9/6 per doz. per doz. 100 c.c. lid. each 10/6 per doz. CROSS STREET • HATTCJN GARDETST, E- C BAIRD &WLOCK (LONDON) LTD. SOLMEDIA (SOLID CONCENTRATED CULTURE MEDIA, POWDERED) (Illustrations taken from typical bacterial growths on Sol media). ILMEDIA RIGAISKI »H«ADI Typhosus 18 « 10 Solmedia in tubes, about two thirds full size ; each contains sufficient Sol, nedia in powder to make 12 X 5 c.c. tubes of media (see instructions for use sent with e; PRICES ON PAGE 114. BAIRD &TATLOCK. (LONDON) LTD. SOLMEDIA (Solid Concentrated Culture Media Powdered). 539 Sole Agents:— BAIRD &, TATLOCK (LONDON) LTD. These are preparations of Bacteriological Culture media in a highly concentrated powdered form, originated by Mr. F. R. Chopping, Assistant in the Clinical Laboratories at the Westminster Hospital and exhibited at the meeting of the Royal Microscopical Society on April 20th, 1910 (see reports). They are prepared for us under his supervision, are of small bulk, and do not deteriorate. The method of using the media, which is extremely simple, is as follows : — 5 c.c. of water are to be added to a given weight of Solmedium in a test tube, the test tube is then placed in a water bath for 30-45 minutes, and afterwards allowed to set in the required position. If a number of tubes are required the Solmedium can be placed in a flask or beaker, the requisite amount of water added, and the whole placed in a water bath until the Solmedium is dissolved, it is then tubed, the test tubes placed in the water bath for 30-45 minutes, and afterwards allowed to set in the required position (i.e. sloped or for stab cultures). Thus tubes of sterile media are easily and quickly prepared. The following Solmedia are made and have been found to be quite satisfactory : — SOLMEDIA AGAR-AGAR Glycerine Agar, and Glucose Agar are readily made from Solmedia Agar-Agar by dissolving in 5% Glycerine solution or 2% Glucose solution instead of water. SOLMEDIA DRIGALSKI-CONRADI, SOLMEDIA SABOURAUD'S MEDIA, SOLMEDIA PEPTONE BROTH, SOLMEDIA BILE SALT AGAR (McConkey). It will be readily seen that many modifications may be made (for experimental purposes, etc.) by using various solutions instead of plain water. Solmedia is supplied in tubes containing sufficient for 12, 50, or 100 5 c.c. tubes, with directions for use. PRICES. 539T AGAR-AGAR, SABOURAUD, PEPTONE BROTH, OR BILE SALT AGAR. Solmedia for . . . . . . 12 50 100 5 c.c. tubes. Each .. .. .. I/- 3/6 6/6 DRIGALSKI-CONRADI. Solmedia for Each 12 1/6 50 5/6 100 91- 5 c.c. tubes. 14 -CROSS STREET • HATTCTN GARDEN, E-C 114 @H A &*,•* BAIRD &.TATLOCK (LOM)ON) LTD. 537 538 17 Troughs of glazed lireciay for placing on Bacteriological Hrnch a devised hy Mr. ( or.un of the Clinical Research Association, size of outer trough, 7 in. hy 5 in. by 5 in. I'cr pair. 6/- ; per du/.rii p.ur- li" troughs have been devised to hold cultures, etc., in antiseptic solution wliidi h.ive t.. In- ij.-,r: outer trough contains the fluid, and the inner is perforated near bottom and is pruvulrd with ll.inur .it i,,|, est on outer trough. There is a saving of fluid, as the inner trough can he lifted out of solution, tout. :royed, and then trough replaced in the same solution. £3 10 0 JT Bacteriological Specimens, mounted on 3 by 1. Actinomycosis, culture and tissues, 1/9 each. 2. Bacillus Acidi Lactici, culture, 1/9 each. i. Bacillus Anthracis : culture, impression, blood, spleen juice, and tissues, 1/9 each ; spores, 2/3 each. 4. Bacillus Anthrax Symptomatic (Rauschbrand), cul- ture, i/o. each. 5. Bacillus Bubonic Plague, culture and tissues, 1/9 each. 6. Bacillus Coli Communis : culture, 1/9 ; flagella, 5/6 each. 7. Bacillus Diphtheria : culture (various ages) and membrane, 1/9 each. B. Bacillus Diphtheria, pseudo-culture, 1/9 each. 9. Bacillus Dysenteric, culture, 1/9 each. 10. Bacillus Kilamentosus : culture, 1/9 ; spores, 2/3 each. 1 1 . Bacillus Fluore*cens Liquefaciens, culture, 1/9 each. 12. Bacillus Fowl Cholera, culture, 1/9 each. 13. Bacillus Friedlander, culture, 1/9 each. 14. Bacillus Gaertner, culture, 1/9 each, i;,. Bacillus Icteroides, culture, 1/9 each. i(>. Bacillus Lactis Aerogenes, culture, 1/9 each. 17. Bacillus Leprs, in tissues, 1/9 each. 18. Bacillus Malignant CEdema, culture, 1/9 each. KI. Bacillus ?.lallei (Glanders), culture and tissue, 1/9 each. 20. Bacillus Megatherium, culture, 1/9 each. •i I iacillus Mesentericus : culture, 1/9; spores, 2/3 each. 22. Bacillus Prodigiosus, culture. 1/9 each. i in. slides. S 23. Bacillus Proteus VulgarU : culture, 1/9 ; Atgella. j/6 each. S 24. Bacillus Pyocyaneus. culture, i/y each. S 25. Bacillus Subtilis : culture, 1/9 ; spores, 2/3 each S 26. Bacillus Swine Fever, culture, 1/9 each. S 27. Bacillus Tetam : culture, 1/9; llagella, 5/6 each. S 28. Bacillus Tuberculosis : culture, sputum, and turaes. 1/9 each. S 29. Bacillus Tuberculosis? pseudo-culture. 1/9 each. S 30. Bacillus Typhosus : culture, 1/9; flageUa, 5/6 each. S 31. Bacillus Violaceus. culture, 1/9 each. S 32. Micrococcus Gonorrhoea, pus. 1/9 each. S 33. Micrococcus Mclitensis, culture. 1/9 each. S 34. Micrococcus Tetragenus, culture, 1/9 each. S 35. Pneumococcus. culture and sputum. 1/9 each. S 36. Sarcina Lutea, culture, 1/9 each. S 37. Staphylococcus Cercus Flavus, culture, 1/9 each. S 38. Staphylococcus Pyogenes Albus, culture, 1/9 . Bacillus Dysenteria; " Shiga." 17. Bacillus Dysenteric 1'. 18. Bacillus Filamcntosus. 10. Bacillus Fluorcsccns liquefacieus. 20. Bacillus Fluorescens non-lique- facieus. 21. Bacillus Fowl Cholera. Z2. Bacillus Friedlander. 23. Bacillus Gaertner. C 24. Bacillus Gaertner B. C 25- Bacillus Icteroides. C 26. Bacillus Lactis Aerogenes. C 27- Bacillus Malignant (Edema. C 28. Bacillus Mallei (Glanders). C 29. Bacillus Megatherium. C i°- Bacillus Mesentericus. C 31- Bacillus Morgans No. I. C 32- Bacillus Plague. C 33- Bacillus Prodigiosus. C 34- Bacillus Proteus Vulgaris. C 35- Bacillus Proteus Zenkeri. C 3°. Bacillus Pyocyaneus. C 37- Bacillus Subtilis C 38. Bacillus Snipestifer. C 39- Bacillus Swine Fever. C 40. Bacillus Tetani. C 41. Bacillus Tubercle Avian. C 42. Bacillus Tuberculosis Bovine C 43- Bacillus Tuberculosis Human. C 44- Bacillus Tuberculosis pseudo. C 45- Bacillus Typhosus. C 46. Bacillus Typhosus p.ira A. C 47- Bacillus Typhosus para B C 48. C 49 C 50. C 51. C 52. C 53 C54- C 55- C 56. 57- 58. 59 60. C 61. C 62. 63. "I C 05. C 66. C 67. C 68. C 69. C 70. C C C C C £030 Bacillus Typhosus para Brian and Kayser. Bacillus Violaceu^ Gonococcus. Meningocoi Micrococcus Catarrhalis Micrococcus Meln MicrococciH Roseus. Micrococcus Tctragenus. Micrococcus Zymogcnes PnwiBtococciu Sarcina. Sporothrix. Staphylococcus Pyogcnes Albus. Staphylococcus Pyoxenes Aureus Sta;>hyli polished counting plate 15 centimetres square, with quadratic metres .. 555 Glass Counting Squares, divided into centimetres for lxMtd with di.iwt divisions -l's apparatus. No. 554 £0 12 6 £0 < <• 556 558 556 Cardboard Counting Squares, divided into centimetres, black, numbered in whit.' figures ........ CO 0 4 557 Paper Duplicates of above, numbered for registering colonies 558 Esmarch's Counting Apparatus, on stand (XT.!./ tO 0 6 £0 18 0 559 560 • per doz. £004 559 Pake's Enumerating Discs, on paper (See Journal of Pathology and Bacteriology, July, 1896.) E>0 Counting Disc, of glass, in brass frame, for counting the colonies in Petri dishes each £0 10 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 119 £T BAIRD &TATLOCK. (LONDON) LTD. 561 562 561 Lens for counting lines, on tripod foot 563 each £0 2 562 Lens fitted to stage with handle ; the stage is provided with clip so that a specimen on Micro slide can be fitted and passed round the class for examination . . . . each £0 6 563 Coddington Lenses, in horn mounts 15 mm. 20 mm. £0 5 £0 6 564 565 564 Lenses, in horn mounts, single Diameter Price 565 Lenses, in horn mounts (double magnifiers). Diameter Price 566 Lenses, in horn mounts (triplet magnifiers). Diameter Price 566 15 1/4 25 1/9 35 2/3 50 mm. 3/- each. 15 2/1 25 2/6 30 40 mm. 5/- each. 15 20 3/3 25 3/6 35 mm. 4/6 each. CROSS STREET • HATTOTST GARDEN, E- C 120 cr 567 • 568 567 Reading Lens, strong bi-convex nickelled frame, broad rims, polished black woo,! handle, first quality. Diameter T.\ 2 2\ 3 3$ 44! 5 in Price 2/- 2/6 3/- 4/- 5/6 7/6 9/- 10/6 each. 568 Condensers for microscope, on brass stand, with ball and socket joint, plano-convex lens. Small si/.r, z\ in. diain. of lens Large size, 4 in. diain. of lens £0 15 0 £1 1 0 569 569 Kale's Patent Double Roller Mincing Machine, with roller cleaner 570 Mincing Machine, small size, galvanised iron H 571 Mincing Machine, medium size, galvanised iron 570-571 each £0 18 6 £0 12 0 £0 16 0 121 BAIRD & TATLOCK (LONDON) LTD. 572-573 572 Meat Press, 2 quart, galvanised iron 573 Meat Press, 4 quart, galvanised iron 574 Dr. Klein's Meat Extractor 575 Meat Juice Extractor, new pattern, specially adapted for the extraction of the juice from meat each £1 1 £1 10 £1 1 £0 10 576-577 Pathological Microscopical Specimens. respectively, will be found preparations which are to the student ,„«, 576' Set of Medical Specimens. i. Lung, acute lobar pneumonia (red hepatisation). 2. 3- 4- 5- 6. 8.' 9- 10. II. 12. IS- M- IS- 1 6. »7- 18. (grey hepatisation). broncho-pneumonia. ,, tubercular broncho-pneumonia. ,, tubercle. „ haemorrhagic infract. ,, fibrosis (chronic interstitial pneumonia). brown induration. ,, emphysema. ,, secondary growth (sarcoma) Heart, fatty degeneration. vegetative endocarditis, fibrosis (chronic myocarditis). ,, brown atrophy. acute pericarditis. Atheroma of aorta. Liver, fatty infiltration. ,. amyloid (or lardaceous disease). Complete Set in pinewood box 19- Liver, nutmeg (chronic venous congestion). 20- ,, cirrhosis. -2i. ,, perihepatitis. 22. ,, syphilitic gumma. 23- ., miliary tubercle. 24. ., secondary growth (carcinoma. 25. Kidney congestion (cardiac kidney). 2 < >!>!!!• 41. Endometriti^ 42. External Haemorrhoids. 43. Exophthalmic Goitre. 44. Fa' 45. Glandular Polypus 46. Hydatid Soilio-x 47. Hydatidiform Mole. 48. Keloid of Neck. 49. Lupus 50. Papilloma Anus 51. Ovarian cyst 52. Rectum. 53. Beaded Ribs (nckets). 54. Sarcoma, haemorrhage mydoul [CHEMICAL AND SCIENTIFIC'APPARATUS AND PURE Cl -MICA 123 BAIRD &TATLOCK. (LONDON) LTD. 579 580 581 579 Copper Plate, 7 by 3 in., on legs, for drying micro slides, etc. . . . . each £026 580s Stand, Copper, nickel-plated, for drying microscope slides, with small bunsen burner ,, £0 12 6 581 Microscope Slide Heater, of tin, with depression, 3j-in. by 3j-in. by J-in., for placing across tripod stand . . . . . . . . . . . . . . . . per doz. £026 582 Microscope Slide Heater, as above, depression 3^-in. by ig-in. by |-in. £020 £0 1 3 £020 583 584 585 586 583 White Porcelain Trough, with grooves to hold five slides for staining .. each 584 White Porcelain Trough, ,, „ „ vertical form 585 White Stoneware Saucers for staining sections. Diameter . . . . 2 2\ 3 in. Per dozen .. .. ..I/- I/- l/- 586 White Stoneware Dishes, 4 by 4 by |-in., with raised supports in bottom for staining microscope slides, etc. . . . . . . . . . . each 4d. ; per doz. £036 587 588 587 White Porcelain Trays for staining micro slides, 6i by 2|-in. by J-in. deep 588 Plate, white porcelain with black centre, for examining sputum each £0 1 3 £0 1 6 CROSS STREET • HATTON GARDETST, E- C BAIBD &TATLOCK. (LOM)ON) LTD. 589 590 589 Glass Staining Troughs, for sixteen slides, with glass covers 590 Glass Staining Troughs, with glass lids . . each each, 2/- ; per doz. 591 Steinach's Dishes for staining. The outer dish contains the solution, and the inner dish (which has a perforated bottom), the section to be stained. Outside diameter of outer dish .. ,. .. ..5 10 centimetres. „ „ inner dish A ~ T* 1- In Each 3/6 5/6 £020 £120 592 593-595 592 Staining Trough for microscope slides, new pattern. This trough is made of moulded glass with grooves for ten 3 by i in. microscope slides. A pair of extra grooved supports is supplied, which are suitable for microscope slides ij by I in. These supports are placed inside the trough in use and can be removed when 3-in. slides are inserted. Price, with extra grooved supports . . . . . . each 3/- ; per doz. £1 14 0 593 Staining Tray, new form, of thick glass with grooves for twenty 3 by i in. slides placed back to back, open at bottom so that the tray can be lifted out of one solution by means of clip and placed in another without removing the slides . . each, 1/9 ; per doz. £100 594 Staining Dish, with cover for above 595 Clip for above 4d. ; £130 £039 •CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 125 BAffiD &TATLOCK. (LONDON) LTD. 596 597 596s Staining Clip for Slides (Registered Design). This Clip was designed for use where a number of 3 by I in. slides are required to be stained, dehydrated, etc., at one time. The clip will hold ten slides of all ordinary thickness very securely, and the whole batch can then be manipulated as one article through the different solutions as required. The slides are easily fixed or removed from the holder, which is very simple in construction, there being nothing to get out of order. It is so made that it will rest on a table as illustrated, and so facilitate the fixing or removal of the slides. The clip, which is made entirely of metal and silver-plated, will also hold the extra wide (3 by ij in.) slides, in which case, however, a wider glass jar than that illustrated is required. A. Staining Clip and Glass Jar complete B. Staining Clip only C. Glass Jar only each, 2/6; 1/9; 9d. , per doz. 597s Rocking Apparatus, as devised by Dr. E. F. Bour for keeping microscope slides in motion while staining. The rocker carries 4 slides, and when the pendulum is set in motion it will rock the slides for about 5 minutes . . . . . . . . . . each £1 7 £0 19 £0 8 £0 4 598 599 598 Staining Troughs, clear glass, polished, 85 by 40 by 25 mm. to hold 3 by i in. microscope slides . . . . . . . . . . . . "each, lOd. ; per doz. £0 9 599 Porcelain Pots with perforated bottoms, for use in staining tissues, etc. Height . . . . . . . . . . . . 2i 2 in. Diameter . . . . . . . . . . 2 li in. Each .. .. .. .. .. ,. 9d. 5d. Per dozen . . . . . . . . . . 8/6 4/6 CROSS STREET • HATTOTST GARDETST, E BAIRD &TATLOCK. (LONDON) LTD. 600 Section showing Cover Glan in |>o-.itiiin 600 (0 Ellington's Staining Trough for bacteriological work. This trough was devised by Dr. Kdington, late of the Government Bacteriological Laboratory, Grahatnstown. Four sets of cover glasses can be stained in the same solution without the possibility of mixing, the divisions being numbered. The bottom of the trough is slightly concave. This enables the operator to easily pick up the cover glasses with the forceps without danger of them breaking. The trough is made of white glazed porcelain, and each division will take cover glasses up to i by i in. . . . . . . each, 1/6 ; per doz. 601 («ls Dr. Bulloch's Apparatus for obtaining plate cultures or surface growths of obligate anaerobic bacteria (See Cenlralblatt fur Bacteriologie, 1900, XXVII., p. 140.) 1 1» principle of the method is a combination of displacement of air by an inert gas, and the subsequent •jiiplete removal of oxygen by alkaline pyrogallic acid, the alkaline solution entering the apparatus after the air 1- been displaced. To work the apparatus, the lower edge of the bell glass is smeared with a small quantity of Wi,'t. resinas. A deep Petri's dish is then placed on the centre of the glass slab, and standing in the centre of m. Per pair .. 4d. 5d. 7d. 8d. lOd. lid. 1 «. Per dozen pairs . . 3/6 4/6 6/- 7/6 9/- 10/- 17/6 638 Glass Basins (Petri Dishes), in pairs, for cultures, depth 15111111., unpolished. Diameter of bottom dish . . . . . . . . *..;.'. 4 m. Per pair . . . . . . . . 7d. 9d. Per dozen pairs . . . . . . . . . . . . 6/- 8/- 639 640 639 Petri Dishes, large size, as used by the Pasteur Institute of India, etc., bottom dish 22 cni. diameter by 22 mm. deep. per pair, 2/- : per dozen pairs £1 3 0 640 Petri Dishes, with shoulder, polished lid and bottom of lower dish (German War Office pattern), diameter of top dish 10 cm. .. .. ., .. per dozen pair-. 641 Double Dishes, in pairs, shallow, for water analysis, 5 mm. deep, j| in. diiimei' ;•;*. 636/638) . . . . . . . . • . . . . . . .. per pair £0 1 0 642 Glass Basins, strong, with drop-on covers Diameter, external Price each Price per doz. 642 ;rs. 2 3* 4 4Jin 5d. lOd. I/- 1/1 4/6 9/6 ll/- 12/- BAIRD &.TATLOCK (LONDON) LTD. -"^-«=» S. 643 643 Glass Basins, strong, with covers ground to fit. Diameter, external Price each Price per doz. 644 Glass Basins, tall form, with drop on cover. Height Diameter, external Price each 644 2 2| .;.! in. 7d. 9d. V- 6/6 8/6 ll/- .. 6 7.1 in. 4 5 1 in. 1/6 2/3 645 646 647 648 645 Solid Watch Glasses, Professor Minot's pattern, for staining cover glasses, etc., 2 in. diam. internal, 2^ external 646 Glass Capsules or Pots, shallow, clear glass. Diameter .. ii 2 2\ Price each . . 3d. 3d. 4d. Price per doz. . . 2/6 2/6 3/6 per doz. 4/6 ; per gross £2 12 3 4d. 3/9 4 5d. 4/6 647 Glass Basins, with ground flange, and lid with knob ground to fit. Diameter . . . . . . . , '2 z\ Depth . . . . . . . . ITSB z| Price each . . . . . . . . 9d. 10d. Price per doz. . . . . . . 8/6 9/6 648 Glass Sporulating Dishes, flat, with grooved cover ground to fit. Diameter . . . . . . . . . . i Depth .. .. .. .. .. .. j Price each . . . . . . . . . . 6d. Price per doz. . . . . . . . . . . 5/- 5 8d. 7/6 lid. 10/6 i 7d. 6 in. lid. 10/6 4 in. I/- 11/6 2 in. ij in. 8d. -CROSS STREET • HATTCXN GARDEN, E-C BAIRD &TATLOCK LONDON) LTD. 649-650 651 652 653 649 Porous Blocks for Sporulating, conical shape, as used by brewers, ifV»- top by \ in. deep. IXT do/.. £016 650 Porous Blocks for Sporulating, conical shape, as used by brewers, i| in. top by f in. deep. perdoz. £0 1 6 651 Square Petri Dishes, 10 cm. by 10 cm. by 15 mm. deep, in pairs .. .. per pair £020 652 Gabritschewsky's Double Tetanus Dish, with lid . . . . each £030 653 Glass Jar, 8 by 5| by 3 in., for storing bandages, tubes, etc., with metal lid each, 4/6 ; per doz. £2 12 0 654 655 656 654 Glass Jars for storing tubes of media, etc., fitted with lids of tin plate. 8 by 4$ in. 9 by 5! in. Price each .. 2/3 26" Per doz. 26/- 29/- 655 Jar of Brown Glass, Dr. Shattock's pattern, 8 in. high by 4^ in., with lid ground on, for storing Anasrobic Cultures in Petri dishes, with tinned iron frame to hold six 3j-in. Petri dishes . . . . . . . . . . . . each, 6/6 ; per doz. 656 Bell Jar, clear glass, 9 by 6 in., with ground flange and knob, fitted with copper rack for holding Petri dishes, etc., for use on air pump plate, size. Price with rack (without pump plate) . . . . . . . . . . . . . . . • each £3 12 0 £0 12 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 657 658 657s Pocket Microscope Accessories Cabinet . . . . . . . . each £0 16 This pocket cabinet was devised by Dr. Rees, late of the London School of Tropical Medicine, for taking and mounting microscopical specimens at the bedside for subsequent microscopical examination. Each contains two trays with three numbered divisions for slides, one tube for holding cover glasses in alcohol, one tube for needles, one tube for vaseline, ten grooves for holding slides, and compartment under lid closed by flap, for holding papers, gutta-percha tissue, cloth, etc. The whole box is made of German silver, so can be thoroughly sterilised, and is particularly well suited for use in the tropics. 658s Cooling Apparatus for Media, etc., as devised by Dr. W. G. Savage. Copper with plate glass top . . . . . . . . . . . . . . each £1 9 ENTOMOLOGICAL APPARATUS. 659 659s Outfit for Collecting and Preparing Mosquitoes, prepared in accordance with the pamphlet issued by the Director of the Museum (Natural History), and adopted by the British Crown Agents for the Colonies . . . . . . . . each £2 660s Compressed Cork Sheets (Suberit) for pinning out specimens of insects, etc. 12 by 6 by J- in. 12 by 6 by £ in. 12 by 6 by J in. Price .. 6/- 8/- 12/- per dox. CROSS STREET • HATTCTN GARDETST, E'C BAIRD &TATLOCK (LONDON) LTD. 12 3*5 63 10 1+ IS 16 17 IK •AIRO I TATLOCK ILONOMIC 661 >61 Entomological Pirts, silvered (illustrations full size). Nos. . . i 2 3 4 5 8 9 10 14 15 Per o/. I/- I/- I/- I/- 1/6 21- 2/6 3/- 2/6 3/- Nos. i to 5 in J oz. boxes ; Nos. 8 to 19 in J oz. boxes. » >62 Pocket Folding Net, 3 joints, cane >63 Pocket Folding Net, 4 joints, wire >64' Wand Telescopic Net, 3 joints . . ij65' Sugaring Net .. »66' Zinc Killing Box 61- 17 IH 3/6 5/6 19 7/6 each £036 ., £046 .. £096 „ £076 £0 I 0 i67T Setting Boards, flat, 14 in. long. i I I Ij 5d. 5d. 6d. 7d. 8d. 9d. lOd. lid.. I/- 3 1/2 3i 1/4 4 1/6 4i 1/8 5 i" 1/10 i68T Setting Houses, with 10 corked setting boards, drawer for pins. Perforated zinc door, brass handle, etc. Size 12 by 9 by 5 in. >69' Store Boxes, with camphor cells. Corked deal covered with green cloth, book pattern, air-tight. 14 by io£ in. 16 by n in 8/6 9/6 (>70T Boxes, wich glass bottoms i ij it 2 2^ 2.1 1/11 2 /- 2/2 2/6. 3/- 3/6 each £096 17! by 12 in. " 10/6 3 in. 5/6 per doz. 671 S71 Boxes, metal, glass bottoms, il-in. diameter V72' Boxes, with glass lids. 1/2 , 1/6 1/9 J731 Boxes, as No. 672, in riests, four sizes, I in. to 2 in 673 2/4 3 2/9 per doz. £0 I 2 3i in- 3/6 per doz. per doz. £0 I 8 cr BAIRD &TATLOCK (LOM)ON) LTD. J-i 674 674T Insect Cases, corked and prepared, suitable for exhibition purposes, with camphor cells and glass framed top in mahogany. 10 by 8 in. 13 by 9 in. 14 by 10 in. 16 by 10 in. 16 by 12 in. 18 by 14 in. 3/6 5/- 5/6 6/- 7/- 8/- each. DOULTON'S GERM-PROOF FILTERS. 675A 675s 675c 676 MEDICAL TESTIMONY FROM EMINENT BACTERIOLOGISTS, WHO REPORT THUS :— " From exhaustive experiments which have been made it is clearly demonstrated that Doulton's White Filter Tube is equal in every respect to any filter in the market at the present time. It has, in fact, been tested against that tube which, up to the present, has been admittedly the best, and, in not a few experiments, it excelled this well-known filter both in regard to rate of filtration and in its power to keep back minute liying mobile microbes. We have submitted the White Filter Tube to severe tests, and it is in all respects most satisfactory. In short, after a series of tests, the conclusion come to is — that the Doulton Porcelain Tube prevents the direct transmission of microbes both from water and from highly nutrient liquid media, such as peptone bouillon and peptone water." 675T A, B, or C, Filter Tubes, 8 by i in. .*. .. .. .. .. each 676T Filter Tubes, 3 by i in. £0 3 £0 1 6771 A 677 C Doulton's Bacteriological Filters, illustrations are half size. A. B. C. Price 2/6 2/- 4/- each. -CROSS STREET- HATTCTN GARDEKT,' E- C 138 Kl BAIRD &TATLOCK (LONDON) LTD. • 2 > * 678 679 (Method of fixing to mam supply.) 680 682 683 684 78T Doulton's Germ-Proof Filters (Admiralty pattern). As will be seen from above section, the method of attachment is of the simplest character, the Germ-Proof Tube being easily removed for periodical sterilising by boiling. The niters are fitted with rings between the outer case and the container or lining, and also between the container and lid, to prevent vibration and breakage. , The cleaning instructions are printed and burnt on the ware, thus avoiding the use of adhesive paper labels. Prices . . 23468 gallons. 26/9 37/9 48/9 69/- 91/3 each. Extra tubes, 3/6 each. 79T Doulton's Germ-Proof Filters (cheaper form than above). 123468 gallons. Prices . . . . 14/3 20/9 29/3 38/3 56/3 72 /- each. Extra tubes, 3/6 each. >80T Doulton's Pressure Filter for household use. Nickel plated filters fitted with sterilising tubes and attachment to water service. Will deliver from 5 to 15 gallons per day according to pressure. These filters are a great convenience in all households where a constant supply of perfectly filtered water is required .. .. .. .. each £0 18 0 •81T Extra Tubes for above, size 8 in. by i in. . . >82 Kitasato's Porous Tubes, for filtering •83 Chamberland's Porous Filter Tubes, 8 in. by i in. i683 Chamberland's Porous Filter Tubes, 6 in. by $ in. £036 each, 5d. ; per doz. £046 each £036 £036 >84T Chamberland's Porous Filter, 8 in. by i in., mounted in metal tube with stopcock to fit to water supply .. .. •• •• each £150 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &.TATLOCK (LONDON) LTD. 685 686 687 688 685T Klein's Laboratory Filter, i litre capacity, fitted with Pasteur-Chamberland filter tube (Fig. 683) .. .. .. .. .. each £2 5 686 Massen's Filtering Apparatus, capacity .500 c.c., complete with porous filter and india- rubber cap . . . . . . . . . . . . . . . . each £0 14 687 Cobbett's Filtering Apparatus, with Kitasato's candle, Fig. 682 688 Cobbett's Filtering Apparatus, with Chamberland-Pasteur candle, Fig. 683 £0 3 £0 6 689 689 Massen's Filter Candles with porcelain heads. 690 Size No. 76 71 73 70 75 77 72 Total Height 90 83 70 60 55 42 37 mm. Diameter, external 14-5 23 II 17 12, 5 13-5 15 mm. Diameter across porcelain head 30 38.5 22.5 32 23 25 28 mm. each, lOd. ; per doz. £0 9 6 690 Reichel's Filter, complete with porous candle, indiarubber cap and washer each £0 5 6 691 «/? Porous candle only for above <:TS>^S ' if^T^t -^T^^KrS£Sf^^~^ — <-£&—?*' £0 -^ 2 6 tsfcm I 14 -CROSS STREET • HATTCHST GARDEN , E-C- III 140 e^r 692 693 694 •W Dr. Paine's Laboratory Filter, mounted complete with filter candle as shown A. B. Candle, 5| by |,\ in. Candle, 6 by i in. 3/6 7/6 each. Description. — The apparatus consists of a cylindrical glass tube (a) having a small side exhaust tube (B). IK h is partly covered with a piece of rubber tubing (r1). Over the latter is slipped a larger tube (f) furnished th a nozzle and plugged with cotton wool. The cylindrical tube is corked by a rubber stopper through which passes a porcelain " candle " or " bougie ' In. which reaches to the bottom of the tube. The candle is also corked by a rubber stopper through whicli pass two glass tubes (D) and (E). The tube (D) (delivery tube) extends a short distance into the candle, whilst its horizontal portion is pro- cted by a larger glass tube (the cap) (F), closed at one end and connected to the smaller tube by a piece of ibber tuLing (r11) similar to (r1). The tube (E) (the exhaust tube), is fitted with a larger tube bearing a nozzle (o) by a piece of rubber tubing '") similar to tube (F). Manipulation. — The candle and its attachment are sterilised separately. The fluid to be filtered is put in r cylindrical glass tube (A), and after all the rubber connections have been made air-tight, the exhaust tube |) connected with an exhaust pump. The fluid is thereby sucked into the candle, and when sufficient In- i--rd through, the apparatus is disconnected with the pump, the cap (r)is slipped off the rubber tubing (r") ltd the fluid poured out through the delivery tube into a sterile receptacle. N.B. — Care should be taken to disconnect the pump before any fluid has been drawn on into the cotton «il of the exhaust tube ; otherwise the fluid will not flow readily out of the delivery tube. The apparatus may be used for combined cultivation and filtration. — For this purpose the cylindrical tulic may be plugged with cotton wool and served as a receptacle for the culture medium, which is subsequently it-red by attaching the candle. In this way the risks attending pouring dangerous cultures from one vessel I another may be avoided. For anaerobic cultivation it is only necessary to join two cylindrical tubes together as shown in Fig. 2 by piece of pressure tubing fitted with a screw clip, the two tubes being corked by rubber stoppers. In one tube is placed the culture medium, in the other absorbent fluid, e.g. a solution of caustic potash Hid pyregallic acid in the tabloid form. When all the oxygen is absorbed, the culture tube is sealed off by the screw clip and detached from the Ikhatist tube containing the absorbent mixture. |93 Novy's Filtering Apparatus, complete with stand . . . . each 94 Novy's Filtering Apparatus, new form, for filtering bacterial fluids, the cylinder is fitted with ordinary candle ...... . . each See Centralblatt jiir Bacteriologie, Band XXXV., No. i, 5th November, 1903). 95' Klein's Filter, small size, for filtering toxins in vacuo, with Pasteur-Chamberland porous candle, 6 by i in. reservoir to hold 100 cubic centimetres . . . . . . eat -h 695 £0 18 0 £100 £150 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 141 rap BAIRD & TATLOCK (LONDON) LTD. // II' 696 703 704 705 696T Berkefeld Filtering Apparatus, complete with filtering candle, 2j by | in., container, vacuum flask, and exhaust pump .. .. .. .. .. each £0 12 Prices of separate parts. 697T Metal Pump 698T Porous Filter . . 699T Reservoir 700' Flask with Side Tube . . 701- I.R. Tubing 702' I.R. Cork £0 6 £0 3! £009 £0 1 6 £009 £009 703' Berkefeld Filter, candle, 8 by i in., with glass cylinder and filter flask, with side tube for connecting to pump . . . . . . . . . . . . each £076 704T Berkefeld Laboratory Filter, with reservoir ; size of porous tube, 8 by i in. ; capacity of reservoir, 2 pints . . . . . . . . . . . . . . each £076 705T Berkefeld Filters, in metal case with funnel at top, specially adapted for filtering small quantities of Sera, etc. Size Case Filter No. (See 706) Size Price, complete A 9 in. ii 8 by i in. each £110 B 6 in. 22 5 by i in. £0 18 3 C 3 in. long. 25 2 by i in. £0 16 0 •CROSS STREET • HATTQK GARDEN, E-C BAIRD &TM1OCK. (LONDON) LTD. 706 708 |)6T Berkefeld Laboratory and Experimental Filters. 709 DESCRIPTION OF TUBES. No. Length in Inches Diameter in Inches Price about about each A. Cylinders, without mount 26 2J i 11- B. „ 25 3 1/3 C. ,, with glass mount 24 21 i D. ,, with porcelain mount 23 2 i 2/- E. „ „ 22 5 i 2/9 F. ,, ,, ,, II 8 i G. „ 5 8 2 51- H. ,, with metal ,, 21 J 1 1/9 •I. „ „ 20 ii i J. „ 9 2J i 2/3 K „ 8 4i 3/6 L. „ 7 8 i 4/6 M. 4 3 2 N. 3 5 2 4/6 0. „ „ 2 7 2 P. „ I 10 2 5/6 Q. Glass Mantle to suit Cylinder, 9, 20, 21 oo 4 Ij 9d. R „ „ 8 .. 0 8 l| 1/6 „ 3, 4, 7 • • I ii 28 2j- T. „ „ i, 2 . . 2 13 4 3/6 ''7T Small Exhaust Pump, as in Fig. 696, for any of above niters . . each £066 '»8S Dr. Houston's Pressure Filter, with Pasteur-Chamberland porous candle fitted into nickel- plated brass vessel, capacity i litre, with pressure gauge, stopcock, hand force pump, and rubber tube connections, to work up to a pressure of three atmospheres each £450 ' 9s Dr. Houston's Pressure Filter, small size, for filtering toxins, with Pasteur-Chamberland porous candle, 6 by J in., fitted into nickel-plated brass vessel, to hold 100 cubic centi- , metres, with pressure gauge, stopcock, and force pump, and rubber connections, to work up to a pressure of three atmospheres . . . . . . . . each £3 5 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 143 BAIRD dcTATLOCK (LONDON) LTD. 712 710 711 714 710s Pake's Pressure and Vacuum Filter, for u=e with porous candle, vessel containing 2 J litres, with pressure gauge and force pump . . . . . . . . . . each £4 5 (See description, Public Health Journal for March, 1900, page 423). 711T Dr. Lazarus-Barlow's High Pressure Filter, designed for more rapid Filtration of Albuminous and other Colloidal solutions, as used at Cancer Research Laboratories, Middlesex Hospital. The filter is designed for filtering small quantities of liquid through special filter blocks or candles, under pressures up to 100 atmospheres. Price, complete with spare filter and disc . . each £36 0 The above apparatus as shown, consists of a massive cylinder of special bronze, to which is fitted a plunger or piston actuated by steel screw and hand wheel. The screw is bored and fitted with a valve, operated by small hand wheel shown above large wheel, this valve being provided for the purpose of allowing of the escape of air from cylinder. The screw mechanism is attached to upper flange of cylinder, by means of three steel upright supports. An inlet valve is fitted to lower part of cylinder, the upper portion of valve being provided with glass funnel and rubber tube, supported by small bracket. A pressure gauge is fitted, reading to 150 atmo- spheres (j ton per sq. inch). The lower cover of cylinder is removable, and attached to cylinder by steel studs and nuts, and to the upper surface of this plate is secured the filtering medium, made of a special porous substance in the form ol either a hollow candle with flange, or flat disc, both being easily attached and detached. The apparatus is nickel-plated throughout, and fixed to wall by means of a substantial iron casting. 712 Dialysers, glass, Graham's, with gutta-percha rings. A. Diameter, 4 in. . . each £0 3 B. Diameter, 7 in. . . „ £0 4 713 Sausage Skin Dialysers, of parchment, in i metre lengths. Width when flat . . . . . . 50 55 70 mm. Price per length . . . . . . 3d. 3d. 4d. 714 Dialysers, open and ground both ends, glass, with tubulure in middle. Diameter . . . . . . . . 4 8 10 12 cm. Price each .. .. .. .. I/- 1/3 1/6 1/9 CROSS STREET • HATTCTN GARDETST, E- C 144 715 718 719 M5 Dialysers, glass, bell-shaped. Diameter at narrow end . . . . . . . . ij Diameter at wide end . . . . . . . . 3 Price each . . . . . . . . . . 8d. '16 Parchment Paper, best quality, suitable for Dialysers Nos. 712 to 717 "17 Parchment Paper, as above, cut into squares Size . . . . . . . . 12^ Price 4d. 2 4 lOd. 720 2| in. 5 ., I/- per Ib. 15 6d. 20 8d. i Glass Basins of heavy glass, for dialysers — Size . . . . . . .. 8 by 4 in. 10 by 5 in. Price .. .. .. ..1/3 2/6 719 Cylindrical Glass Cylinders of stout glass, for dialysers — Height . . . . 4 5 6 Diameter .. .. • • 3^ 4 4k Price .. .. .. 6d. 7d. l/- '20 Dialysing Filters, by Prof. Dr. Leo Morochowetz, Moscow. 25 c.m. square. lOd. per do*. 12 by 5 in. 3/6 8 4k 1/4 9 in. 4* .. 1/7 .Messrs. Schleicher and Schiill are now making a specially cut and folded Membrane of Parchment Paper or Dialysing. AH exact description of the apparatus will be found in a leaflet by Prof. Dr. Leo Morochowetz. entitled Appareils et Instruments a 1'usage des Physiologistes." Above is a diagram from the above-mentioned leaflet, showing the position of a single filter, also of .1 M-I 1 four filters grouped round an upright standard. The diagram shows how the water flows from one filter into he others. By this arrangement a considerable quantity of water is saved, and also by the arrangement and jldin« of the parchment membrane, an extraordinary large surface for action is produced, advantages which nyone knowing the subject would detect and at once acknowledge. We supply the membranes for the Dialysing Filters to fit funnels of 12 to 15 degrees and 250 nun. high. No. 521 (thick), per 25 membranes No. 522 (thin), 21 Glass Funnels, with cover extra Stands extra. £0 1 6 £0 £0 £026 CHEMICAL AND SCIENTIFIC APPARATUS AND I SMICALS BAIRD &TATLOCK (LONDON) LTD. V*. ,U 724 726 725 722 727 722T Diffusion Shells, No. 579, C. S. & S. These shells are far superior to the parchment paper, be- lt in the shape of a hose or in connection with glass cylinders. Wich the very smallest volume they offer the largest possible dialysing surface, enabling work to be carried on with the smallest outside vessel, combining greatest cleanliness with absolute reliability. The dialysing shells are, for this reason, exceedingly valuable for experiments in the diges- tion of substances such as albumen bodies, serum, in isolating poisonous substances from secretions and excretions. Packed in boxes with sliding covers containing 25 shells. A. 100 by 1 6 mm., per 25 shells B. 100 by 40 mm., £0 £1 723 Watch Classes, flattened at bottom. Size . . . . . . . . 2 Price per dozen . . . . 1/3 1/9 3 in. diam. 21- 724 Soyka's Flat Bottles, for cultivations, polished flat both sides, 6 cm. diameter . . each £0 0 725 Soyka's Flat Bottles, for cultivations, 7 cm. diameter, with one side divided into square centimetres . . . . each £0 3 726 Buckets or Pails, for laboratory use, papier-mache, size io| in. high by loj in. at top, capacity about 2 gallons . . . . . . . . . . . . each £0 3 727s Trays, vulcanite. Size Price each Price per dozen ,=^^3iA If- 11/6 ''v^C^ i -^r^^fi^SSfffT^r^- 7 by 5j in. 1/6 15/- ,_£^C=P. 9 by 7 in. 2/6 291- ^H=v 10'" 14 • CROSS STREET^- HArT9TST GARDEN, E- C jHJ 146 BAIRD &TMXOCK (LONDON) LTD. 728 729 728s Rideal-Walker's Stand, with test tubes and pipettes for testing the co-efficiencv of ,lis- infectants in relation to carbolic acid • • . . i . t ill II \728S Ditto, without glass parts . . • 729^ Dr. Woodhead's Apparatus for the sterilising and cooling of a series of Platinum cups, as used by him m his researches on the standardisation of disinfectants, so arranged that the spoons are always used in rotation, and at a uniform temperature. The stand is marked with position for the bunsen burner, when 2, 3, or 4 spoons are used (Lancet Nov. 20th, 1909, page 1579) .. .. _ each 730T Platinum Spoons, for use with above, mounted in glass handles. Price (variable) 732 Case for Transmitting Samples of Water, arranged by Dr. Houston. The case is felt lined, and holds copper reservoir (for ice and sawdust), closed at top by indiarubber bung, and 6 oz. flat glass bottles, with ground stoppers, for the samples of water. On outside of case is fitted a stout leather strap, and case is provided with lock and key. A731 732 For Price Extra Bottles 2 £1 12 £1 4 15 8 samples. 0 £1 18 0 each per doz., 4/- ; per gross Water Sampling Case, Army pattern, with 8-oz. sample, with double-walled zinc cylinder fitted with brass cover and swinging clamping screws, and I.R. bung for inner cylinder, case of teak screwed together, felt lined and fitted with handle, lock and key . . each £0 12 £0 6 £1 £0 £250 £300 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS.J BAIRD &TATLOCK (LOM)ON) LTD. 734s 735s 736s 737' 738' ll 733-735 (Section) 733-735 736 Cases for collecting and forwarding samples of water for bacteriological examination. As will be seen from the illustration, the bottle A, holding about 8 oz., is filled with the sample and placed in the inner cylinder, which is closed by an indiarubber cork c ; round this cylinder is a jacket B, for ice and sawdust to preserve the sample during transit. The outer cylinder is made watertight by a cap D, fitted with three swing screws, and placed in a wooden case lined with felt and fitted with lock and key, etc. Case with cylinder for one sample . . . . . . . . . . . . each Case with two cylinders for two samples .. .. .. Case with four cylinders for four samples Case for collecting and forwarding samples of water for bacteriological examination, as designed by W. C. C. Pakes, Esq., for containing several 30 or 60 cubic centimetre samples (For further particulars see description in The Science of Hygiene, by W. C. C. Pakes, lisq., p. 76.) £2 0 £2 14 £3 15 £3 0 737 Lamps for the Gasification of Formalin Tablets. A form, including fifty tablets 13 form, including fifty tablets 738 each £0 10 £0 10 CROSS STREET • HATTOTM GARDETST, E- C 148 740 741 40T Formalin Atomiser, nickel-plated, for sterilising the air of rooms by spraying with formalin solutions each £046 11 r Formalin Sprayer, No. 5. This is a strong well-made article in copper, holding about torn pints, with a Pneumatic Pump, weighs about three pounds and a half, and will be found most useful in all cases where Formalin Solutions are required, in the form of a Spray, more especially in Hospital Wards, Churches, Schools, Libraries, etc. £220 DIRECTIONS FOR USE. Unscrew the Filler Cap, and fill the Container with Solution, then replace the Filler Cap, screw i the Delivery Tube, and turn off the Stopcock. Having done this, give a few strokes with the ump, and turn on the Stopcock, when a fine Spray will be developed. Should the Jet get stopped ) with grit, etc., the internal Screw Plug can be removed with a screw-driver and the Gas cleaned it. To spray high walls or ceilings, insert a broom-stick in the hollow handle of the Sprayer. QCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 149 BAIR.D & TATLOCKL (LONDON) LTD. 743 Section of screwed spindle in cylinder with funnel and driving pulley wheel. Machine for the Preparation of Animal Lymph, as manufactured by us to the order of the Government Lymph Laboratories, etc. This machine has been devised for the thorough mixing of the animal lymph with the necessary glycerine. The lymph is poured into the conical-shaped funnel and is carried by means of the revolving spindle through the cylinder. The spindle is of pure nickel screwed with a thread, gradually tapering from a rough thread at top to a very fine thread at bottom. The inside of the cylinder is also of pure nickel. The mixing spindle is run on a compound ball bearing, and is so arranged that it can easily be removed for sterilising and replaced without any difficulty. In order that the bore of the cylinder can be easily cleaned and examined, the cylinder is cut into two halves, and held together when in use by the clamps shown. The machine is mounted on a strong table with marble top, and the working part is encased under a glass cover with hinged door. This cover need not be removed when the machine is at work. By means of this machine the lymph is thoroughly mixed in about fifteen minutes, without any loss of the lymph, which is kept perfectly free from dust. 742T Price of machine if fitted with guide pulleys to be driven by power £18 743T Price of machine if fitted to be driven by foot, with treadle and driving wheel, as illustrated . . £21 10 744T Price of machine, with electro-motor for continuous current, and adjustable resistance coils for starting . . . . . . . . . . . . . . . . £31 0 745T Price of machine, with electro-motor for alternating current, and with countershaft £34 0 When ordering for use with electro-motor, please state voltage of electric supply available and if alternating or continuous current. CROSS STREET • HATTOTST GARDEN, E-C 150 46 747 746 Patent No. 19651. Machine for Filling Capillary Tubes with Lymph by means of water force-pump, as used in the Government Lymph Laboratory . . . . . . . . each 47r Vaccine Lymph Capillary Tube Loading Machine, designed by Major Eutrican. Com- plete with vacuum pump and 5 ft. tubing . . . . . . . . each (For prices of lymph tubes for use with this machine see No. 748.) METHOD OF WORKING THE VACCINE LYMPH CAPILLARY TUBE LOADING MACHINE. The apparatus consists of a glass receiver (A) containing the lymph, closed by a movable cap which when ji-rewcd down makes the vessel air-tight. Through the centre of the cap passes a piston rod (F), carrying at me end a circular horizontal perforated plate. An air-tight packing surrounds the piston rod where it passes through the cap, so that it can be raised or depressed without affecting the state of air tension inside the receiver. Two stopcocks are fitted to the receiver — one, the air-cock (D), communicates with the atmosphere : the other, the pump-cock (E), with an exhaust pump. The capillary tubes sealed at one end are placed, sealed ends first, into a glass test tube of the size supplied. Over the test tube a thick and a thin rubber ring are slipped, the latter nearer the open end. The test tulx' i^ then inverted on a smooth surface, and the open ends of the capillary tubes brought to one level by gentle tapping. The test tube is now gently raised and the two rubber rings slipped on to the bundle of capillary tubes, the correct position being J to J in. from either end. The bundle (E), which consists of about 100 tubes, held together by a thick rubber ring near the sealed •nds ;md a thin rubber ring near the open ends, is now inserted into one of the holes in the circular plate attached o the piston, open ends downwards, sealed ends upwards, and is kept in an upright position by the thick rubber All the holes in the circular plate arc filled in this manner, taking care that the lower ends of the bundles i'proximately level. The piston carrying the bundles is now inserted in the receiver, taking care that the lower open ends of the bundles do not at this period dip into the lymph. The metal cap closing the receiver is screwed tight, the air-cock is closed, pump-cock opened, and the air in the receiver is exhausted by working the pump. \Vln n the vacuum is as "perfect as can be obtained, the piston carrying with it the bundles of tubes is 'lrprr>.sed (this is best done by a twisting motion), until the open ends of the capillary tubes dip into the lymph. 'I he air-cock is now opened and atmospheric pressure drives the lymph up into the capillary tuK-s height to which the lymph is driven depends upon the completeness of the previous exhaustion, vacuum were obtainable, the lymph would completely till the tubes, but in practice it usually stops short abo 1 to J inch from the upper sealed end. £2 10 0 £550 iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 151 BAIRD &.TATLOCK. (LOM)ON) LTD. The lower ends of the bundles are now raised out of the lymph by pulling up the piston, the air-cock is •closed and the receiver slightly exhausted. As the air pressure in the receiver is gradually lowered, the lymph will be observed to run out of the tubes. Experience will soon tell the correct amount that must be withdrawn, and when this has been done the air-cock is opened and the column of lymph will be observed to run up to its former level, leaving the lower ends of the tubes free from lymph. The cap of the receiver is then unscrewed, the bundles taken out, the rings removed, and the open ends rinsed in distilled or sterilised water to remove any adherent lymph. The capillary tubes are now ready for sealing. When the quantity of lymph to be loaded is very small, as happens towards the end of the operation, it is best to load only one bundle at a time, placing it in the central hole of the horizontal plate, for the remaining lymph naturally drains to that portion of the receiver directly under this hole. It is also advisable when loading the last of the lymph to admit air very slowly and allow the tubes to fill gradually. One or two points occasionally require attention. The packing round the piston rod may become dry and cease to be air-tight. This can be remedied by unscrewing the valve, repacking it with a little tow soaked in vaseline, and afterwards screwing the valve tight. The pump, especially in hot damp climates, wants careful attention, and the periodic renewal of the small oiled silk valves contained in the piston and nozzle. If a good vacuum is not obtained, it is usually the fault of the pump. The rubber rings in the cap of the receiver occasionally require renewal. ,It will sometimes be found that when the lymph is thick and viscid, as soon as exhaustion is carried out to a considerable extent the air entangled in the lymph causes the latter to froth up like bottled beer. Under these circumstances, if the air-cock is opened the froth will at once subside. It may be necessary to repeat this operation several times to get rid of the air. It is; however, only very occasionally that this procedure is required. 748 749 750-751 748 Lymph Tubes, capillary, 90 mm. long, about i-i mm. bore (in boxes of 1,000 tubes). A. Best soda glass, clear .... per 1,000 B. ,, soda glass, brown C. ,, English glass, clear D. ,, English glass brown .... » Special Quotations for large quantities. 749 Iron Boxes, 41 by 4! by ij in., with lids, for sterilising lymph tubes each 750 Glass Vessel, conical, for containing lymph, 1,000 cubic centimetres capacity, fitted with loose cover on top, with stand, ring, and clip each 751 Glass Vessel, 500 cubic centimetres capacity. Complete on stand as above 752 Glass Vessels only with cover, 500 c.c., as in figure 750-751 753 Glass Vessels only with cover, 1,000 c.c. „ „ £0 £0 £0 £0 £0 CROSS STREET • HATTCTK GARDETST, E- C 152 BAIRD &1ATLOCK. (LOM)ON) LTD, fit 754 754 Collapsible Metal Tubes, tin plated, with screw caps for storing lymph, etc. Length, excluding cap .. .. .. xi \n 2jjn Diameter j in< ~,[n Price per gross .. 2/6 3/6 (Special prices for quantities and for other si/.es.) 755 Gauze Sponges, non -antiseptic, 4 in. diameter 2 j in iin. per do/.., lOd. ; per gross £090 756 756T Lymph Spoons, Volkmann's for collecting lymph, nickel-plated each £0 15 0 757 758 757T Lymph Forceps, nickel plated, special pattern as used at the Government Vaccine Estab- lishment, length 6| in. . . . . . . . . each £0 10 6 758s Mead's Adhesive Rubber Plaster, a perfectly pliable and self adhesive plaster spread on cotton cloth, applied without heat or moisture, the ordinary temperature of the body being sufficient to ensure firm adhesion. Supplied in lo-yard spools of the following widths. Width i i J i 1 1 2 2$ 3 4 inches. Price 15/- 17/6 20/- 22/6 30/- 35/- 45/- 55 /- 66/6 per doz. spools. BAIRD &L TATLOCK (LONDON) LTD. 759 (Fig. i) 759T Vaccine Table for Calves, as used at the Government Animal Lymph Establishment, table supplied complete with fittings as illustrated and described . . each £35 0 The table, as illustrated, has been specially designed for the convenient and speedy manipula- tion of the calves when under treatment. The top and framework are strongly constructed of oak wood. As may be seen from the illustrations, the top (which measures 74 in. by 40 in. by 2 in.) can be conveniently fixed in either vertical or horizontal position as required. INSTRUCTIONS FOR USING CALVES' TABLE. When a calf is to be fixed on table, the top should be set in a vertical position (Fig. 2, page 155), and the animal led alongside facing the right. The iron supports (N) (N,) for neck are then placed in position, and the outer ends joined by a leather strap. The body of a calf is secured by the long leather strap round table top. The front feet are then fastened with straps (F) (Ft). The near hind foot is secured in clamp (c). The head is held down by straps (H) (K,), though (11,) may not be required. The table top is now tilted back to horizontal position with calf on it and the two bolts at back secured. At the same time the off hind leg of calf is raised so that the hock joint rests in bracket (B) on pillar, the leg being kept in position by clamp (A). The abdomen of calf is then in proper position for operating on. Hot water for shaving and washing purposes is supplied from copper vessel on swing arm (s). To release calf the above operations are reversed. Note that any water accumulated in drainer (D) should be drawn off by cock before tilting table vertical. A bucket should also be placed under table when in use so as to catch any droppings through hole (K). 14 -CROSS STREET • HATTO>T GARDETST E- C 154 v»»V;_7 BAIRD &TATLOCK (LONDON) LTD. 759 (Fig. 2) 60s Patent Indiarubber Vaccine Expeller 760 perdoz. £0 18 0 The tube with sealed ends is first drawn mid-way through the larger opening as illustrated. lir upper end of which is then broken off, and is drawn so far through the hole that the broken end • only about half an inch from the smaller hole. The other end of lymph tube is now broken off ml tin- mount held between the first and second finger whilst placing the thumb over the top open- i? .UK! compressing, the vaccine is immediately expelled. By this means the vaccine can also be istributcd as desired. '61' Purinometer (Dr. Walker-Hall's), without solutions . . eacli £150 (See British Medical Journal, I4th June, 1902, p. 1461. and „ „ „ ist. Nov., 1902, p. 1413.) CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 762 763 762s Urine Test Stand, of mahogany, with drawer, spirit lamp, urinometer in case with graduated immersion tube, eight test tubes with holder, test tube brush, test papers, six watch glasses, stirring rod, microscope slides and cover glasses, plain pipette, six stoppered bottles contain- ing nitric acid, acetic acid, Fehling's solution, iron perchloride, liq. potassas, tine, guaiacum 763s Urine Test Stand, with drawer, with spirit lamp, four bottles, Doremus' Urinometer, Esbach's Albumenometer, four test tubes. Price, complete as figured 764 764s Urine Testing Cabinet, as figured. Length, 17 in. ; width at base, 9 in. with drawer at side. Containing stoppered bottles for following reagents : — Esbach's solution, nkric acid, acetic acid, Fehling's alkaline solution, Fehlmg's copper solution, test papers, iron perchloride, liq. potassa:, tine, guaiacum, ozonic ether, silver nitrate ; and following apparatus : — Urinometer with graduated cylinder in case, spirit lamp, thirteen test tubes, funnel, filter papers. A. Price with bottles empty . . . . . . . . B. Price with bottles filled with reagents 765s Urine Test Cabinet (Army regulation pattern), of polished mahogany, with drawer and fittings as noted below. Price, complete . . £3 0 I £3 5 ( £2 10 ( CONTENTS. 4 2-oz. N.M. Bottles (stoppered). I 4-02. W.M Bottle (stoppered). 12 Books Litmus Paper. i Funnel 8 Test Tubes. I Evaporating Basin I Test Tube-holder. 50 Filter Papers. 4 Test Glasses, with covers. Urinometer Jar. Spirit Lamp. Gilt Urinometer. Plain Pipettes. Stirring Rod. Brass Tripod. CP.OSS STREET • HATTO1ST GARDE1ST, E- C BAIRD ^TATLOCK (LOM)ON) LTD. 766 767 i6s Urine Test Cabinet, fitted with lock and key, containing platinum foil, platinum win-, microscope slides and covers, spirit lamp, stirring rod, test tubes and stand, test tube holder, test tube brush, thermometer, four trial glasses, two conical sediment glasses, urinometer and graduated cylinder, one pair forceps, watch glasses, plain pipette, and bottles with reagents, viz., nitric acid, acetic acid, Fehling's alkaline solution. Fehling's copper solution, iron perchloride, liq. potassae BP., tine, guaiacum, and lie ether. . . each £4 10 per doz. each i7 Urea Apparatus, Dr. Dupre's, complete A. Graduated bottle for soda solution B. Graduated cylinder for hypobromite solution C. Bromine, in hermetically sealed tubes, 2.2 cubic centimetres D. Caustic soda, 100 grammes, with bottle DESCRIPTION AND METHOD OF USING. Hi. Dupre's apparatus, as shown in the illustration, consists of a bottle in which the reaction Ix'tween fix- and hypobromite is effected (A). This is fitted with an indiarubbcr stopper, which carries a small test lie. and a small piece of glass tube connected with the indiarubbcr tube (B), which conveys the nitrogen cd to tlif graduated tube (c), in which it is measured. The upper limb of the graduated tulx- ^ ted with a piece of indiarubber tube and closed by means of a pinchcock (D). The cylindrical pneum.itu- mgh (K) is fitted with a sliding rod and clip (F) which carries the graduated gas tube, and is capable of being u- to letter flose the tube with the indiarubber plug and mix the two liquids by turning the tube gently upside down 1 limes : place the latter in a centrifuge for 2 minutes. ic precipitate of albumen visible on the graduated scale indicates exactly the percentage of albumen When ascertaining albumen in serous liquids, 4 ccm. of the liquid should be poured into the tube inxed with .5 ccm of the reagent, the tube should then be shaken and centrifuged. Any centrifuging machine may be used with our Albuminimeter. \\ hen using a machine with about 2000 to 2500 turns per minute centrifuge for ? minutes, with 5000 turns ninutes, and with 5000 turns 2 minutes. \\ hen testing with pure solution of albumen it should he borne in mind that egg albumen or blood albumen tain only 85 — 90% of Albumen and that the graduation in the albuminimetcr is arranged for physiological retions which possess higher viscosity. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 161 BAIRD & TATLOCKL (LONDON) LTD. SECTION 3. Selection of Apparatus for Chemical Physiology, Blood Testing, 6?c., Centrifugal Machines, &c. COMPLETE CATALOGUE OF PHYSIOLOGICAL APPARATUS SENT POST FREE ON APPLICATION. 786 787 786r Dr. Wright's Blood Coagulation Tubes, mahogany box, containing tin reservoir with indiarubber mat, numbered grid, pinchcock, tube and thermometer, set of twelve numbered pipettes with indiarubber caps, two bundles of wire; six lancets in bottle, aspirating tube and mount, and two stoppered bottles for ether and alcohol . . . . . . each 7871 Dr. Haig's Capillary Dynamometer. The illustration will best describe the instrument. The scale is from o to 20 oz., divided for convenience into 5-oz. quantities. On using the instrument place the thumb edge of the right hand against, say, 15 oz. on the scale ; on then pressing the pad on to the back of the hand the thumb will perceive when the stud touches it, thus indicating the pressure arranged . . . . . . . . each £1 15 £076 CROSS STREET • HATTOTST GARDEN, E-C 162 I BAIRD & 1ATLOCK. (LONDON) LTD. Section III. APPARATUS FOR $MCALPHYSIOLOGY.BLOODTE STING &? CENTRIFUGAL MACHINES Blood Analysis Apparatus Haemacytometers and Haemoglobinometers, etc. Centrifugal Machines Shaking Machines ) Hot Air Engines Pages. 162-167 167-178 181-189 190-192 14, CROSS STREET, HATTON GARDEN. EC The following are the different Sections in ou Catalogue. Those marked * are also printe separately. Pages Nos Section No. 1.* Laboratory Fittings 14-! 2.* Bacteriological Apparatus 57-1 3. Chemical Physiology Apparatus 162^1 4.* Microscopes and Microscopical Accessories 193-3 5.* Balances and Weights 321-3 6.* Chemical Apparatus 383-8 7.* Botanical Apparatus 817-8 8. Gas Analysis Apparatus 843-8 9.* Milk Analysis Apparatus 887-8 10. Refractometers 895-9 11." Oil Analysis Apparatus 903-9 12. Water Analysis Apparatus 927-9 13. Cement Testing Apparatus 934-9 14. Leather Testing Apparatus 947-9 15. Paper Testing Apparatus 950 - 95 16. Physico Chemical Apparatus 952-97 17.* Pyrometers 977-100 18.* Calorimeters 1007-102 19.* Seed and Soil Analysis Apparatus 1023-104 20.* Spectroscopes and Polariscopes 1043-107 21. Volumetric Apparatus 1079-108 22. Anatomical Models 1088-110 23. Meteorological Apparatus 1106-112 24 * » *• i. Assay Apparatus 1125-117 25* » fcX. Chemicals 1187-124 .^—^. ^s?ss9\ rifi*^ fcn 14 • CROSS STREET • HATTOK GARDETST, i/j\ il W . , W "VV^^K •MOB BAIRD &TATLOCK (LONDON) LTD. 788 789 88T Barcroft's Apparatus for the differential Pressure of Blood Gases, No. 1, devised l>v Joseph Barcroft, F.R.S., and H. Roberts. Price complete, as figured . . each £1 10 0 DESCRIPTION. The Apparatus consists of two bottles of identical size (about 30 cc.) attached to a manometer, the tubing which is i mm. bore. The manometer is filled with clove oil of known specific gravity. To fill it take out e centre tube, put in clove oil at (A), put in the centre tube with the glass tube (u) open and apply some pressure i the rubber tube (c). The oil should stand about half way up each tube ; seal (B) in a llanie. The following constants must be determined : (i) the sectional area of the tubing. A ; (2) the size of the tiles, V. To determine A : — The centre tube (x) is marked in i/iooths of a cc. Expel o. i cc. from it into the mano- cter tubes, which are of the same size. 0.05 cc. will have gone into each ; read the difference in level. From e mean of a number of such readings (D) is directly deducible. To determine V : — With a knowledge of (D), V may be obtained by an application of Boyle's Law. Fill bottles almost full of water, putting say 25 cc. of water in each, shut one of the taps, keeping the other H'ii. lighten the screw so as to produce a known compression on the closed side ; observe the difference of essure produced. The tubes should be moistened with oil before the experiment commences. To determine the oxygen capacity of a sample of blood .'—Place 2 cc. of Ammonia solution (made by adding cc. of strong NH3 t6'a'litre of water) ; add i cc. of blood on each side. Thoroughly lake the blood. Put vaseline i the large and small stoppers, place the bottles on the stoppers. Put . 2 cc. of a saturated solution of Potassium •rricyanidc in the small tubes contained in the stoppers (this is best done with a fine pipette which goes down noes). Put in the small stoppers. Place the apparatus on the side of a large water bath (such as a lil). In about five minutes, with both taps shut, rotate one bottle till the Ferricyanide trickles into the laked ood. Shake thoroughly, replace in the bath, repeat this several times till a constant difference of level i-; >tained. Let this difference of level by y mm. ; let p be the height of the barometer in mm. of clove oil. an I the volume of oxygen given off in c.mm. x = y ( - + A I. Except in the most exact work p may be taken 10,000 mm., in which case the expression (- + 0.785 d* j may be determined once for all and called C ; the nstant of the apparatus then x — y + C. See Journal of Physiology, XLIL, p. 512. Barcroft's Differential Apparatus, No. 2, for the Analysis of o.i cc. of blood. Price complete with clip, as figured each For the systematic determination of the haemoglobin worth or dissociation curves of human beings. For iolute values it is best to determine the constant of the apparatus by comparison with the larger apparatus ; same blood being used for both. £0 10 6 BAIRD &. TATLOCK (LONDON) LTD. 790 790s Dr. Leonard Hill Gas Pump, for analysis of the gases of the blood. Price, on stand, with three eudiometers (H), and six blood receivers (F) . . . . . . each ihis pump is so contrived that it can give qualitative results of sufficient accuracy with ten grammes of blood. The pump is admirable for the purposes of class demonstrations on account of its simplicity, cheapness, and rapidity of action. In research work the pump is equally useful, for while the working errors are under i per cent., the physio- logical errors are reduced to a minimum". These latter errors always arise from the withdrawal of those large quantities of blood which are required by the use of all other blood-gas pumps. The pump as shown in the figure consists of a mercury reservoir (A), about 300 cubic centimetres in capacity, which is connected with a second reservoir (B) by means of 120 centimetres of pressure tubing. The upper end of the reservoir (B) is closed by a three-way tap (D). By means of this tap the reservoir (B) can be put in con- nection with either the tube (E) leading to 'the blood receiver (F), or with the tube (c) leading to the eudiometer (H). The tubes (E) and (c) are made of manometer tubing. The blood receiver (F), which also acts as the froth chamber, consists of three glass bulbs connected by short and wide junctions. To either end of the blood receiver is fixed a piece of pressure tubing, provided with a screw clip. This tubing is of excellent quality, and is too thick to collapse under atmospheric pressure. Half-a-dozen such blood receivers are allotted to the pump for the purpose of obtaining successive samples of blood. In using the pump, the successive manipulations are as follows : — A blood receiver is affixed to the end of the tube (E), and the receiver is elevated into the position indicated by the dotted outline. The reservoir (B) is then put in connection with the tube (E) by means of the three-way tap (D), the reservoir (A) is raised above the pump, and the whole system is filled with mercury to the top of the blood receiver (F). The screw clip on the rubber tube at the upper end of (F) is then closed, and the reservoir (A) lowered until the blood receiver is exhausted, except for 2 or 3 cubic centimetres of mercury, which are purposely left within. The screw clip on the lower end of (F) is next Closed, and the blood receiver now clipped at either end, exhausted, detached from tube (E). and weighed. A sample of blood is then collected in the following way : — The arterial or venous canula is filled with blood, and immediately afterwards pushed into the rubber tube at the end of the blood receiver, as far as the closed screw clip. Before the insertion of the canula, the end of the rubber tube is compressed with the fingers to exclude the air within it. A sufficient quantity of blood is now withdrawn by opening at the same time the screw clip, and the clip placed on the vessel of the animal. The blood is defibrinated by shaking it with the mercury left within the blood receiver for that purpose, and the latter is then again weighed. The weight of the sample of blood is then obtained. The blood receiver is next affixed once more to the tube (E), in the dependent position shown in the figure, and the tube (E) is exhausted. Finally, the screw clip between (E) and the blood receiver is opened, and the gases are withdrawn and collected in the eudiometer. Since the blood receiver hangs freely from the tube (E) by means of a piece of rubber tubing, it can be both immersed in warm water, and shaken to facilitate the complete escape of the gases. The bulbous £3 0 CROSS STREET • HATTOTST GARDETST, E-C- 164 t m of the blood receiver prevents tie Wood from frothing over into the P,,n,p ; and ,i the action I " * '"• " ""' be immediately allayed by pouring a few drops of warm water on to th,- tul>r IF) ire thereby dr.ven back into the receiver, and the pump is never fouled. The tap (ui is M mui.ipuUt.- lt the- gases only, ami not the water which condenses in the reservoir (.,). are .Ir.v,-,, „„„ th-- eudioni ,e water is returned back into the blood receiver. Three to four exhaust,,,,,-, .m- -..Undent to rxtr.u t ,11 tl,,- . I from about 10 grammes of blood. The gases are estimated by the potash and pvrogalli< a< i.l mrtl.od The - liometer tubes are surrounded with a water jacket to keep the temperature constant In rescar. I, work hultaneous samples arc drawn from the arterial system, and from the vein leaving the organ th.- met lU wrhich is under investigation. The sample of blood can be drawn conveniently into small Lull* ho ,t i<> cubic centimetres, which have been previously washed out with oil ; from thence th.- bloo.1 ,, rred to the blood receiver. No loss of gas has been found to occur in using this mrthod With tins pump four complete analyses can be done in two hours. I'ici,- Hill and Narbarro on " The Exchange of Blood Gases in Brain and Muscle " (Journal u/ /'/,t 791 792 1 Muscle Chamber for use in conjunction with gas pump, Fig. 790 each £0 17 6 In addition to the blood receiver, a muscle chamber can be supplied with the pump. I his chamber is closed at the upper end by a rubber cork, and the cork is surrounded by a mercury cup. short piece of glass tubing (A) passes through the cork, and this is fitted with a piece of pressure tubing and dip. Two insulated platinum wires (B) and (c) also pass through the cork — one of these ends in a i"k. From this hook the frog muscle preparation is suspended. At the lower end of the muscle is attached i bucket (n), fitted with a vertical rod (E). From the wire (c) passes a piece of fine wire, which is tied nn I each £0 17 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 167 BAIRD &TATLOCK (LOM)ON) LTD. 804 807 804T Haemoglobinometer, Dr. Gowers', for the clinical estimation of haemoglobin, in case each Separate parts : — A. Drop bottle ........ B. Pipette C and D. Standard colour tube, with graduated tube E. Stand F. Needle, guarded . . . . . . . . ,, 805' Gowers' Haemacytometer and Haemoglobinometer combined in one case . . 806' Dr. Haldane's Modification of Gowers' Haemoglobinometer, with descriptive pamphlet Separate parts : — A and B. Standard colour tubes . . . . . . . . per pair C. Pipette, 20 cubic millimetres . . . . . . . . . - each DESCRIPTION. (A) — Bottle with pipette stopper for holding the diluting solution. (B) — Capillary pipette for measuring the blood, (c) — Graduated tube for measuring the amount of haemoglobin. (D) — Standard tint of normal blood. (E) — Support for (D) and (c). (F) — Puncturing needle. (See Report of the Meeting of the Clinical Society for I3th December, 1878.) £3 7 £1 11 807' Haemoglobinometer, Gower-Sahli's pattern each INSTRUCTIONS FOR GOWER'S H^MOGLOBINOMETER, MODIFIED BY PROF. SAHLI. Into the empty graduated glass tube, pour a few drops of pure water, then make an incision with the lancet on the finger tip of the patient ; the cut must not be too superficial otherwise a sufficiency of blood may not be obtained. Any pressure on the finger to hasten the discharge of blood must be exercised only at some distance from the wound, otherwise there is a risk of diluting the blood with the serum from the flesh. When a large drop of blood has been obtained, 20 cubic millimetres are sucked into the capillary pipette up to the mark, carefully wiping the end of the pipette with some cotton wool and taking care to avoid drawing any of the blood out of the pipette. Now blow this measured quantity of blood into the graduated tube, and mix well with the water. By means of the larger pipette dilute this mixture, shaking all the time, until the red corpuscles are dissolved into haemoglobin solution, and the colour of the solution is the same as that in the tube filled with glycerine picrocarmine. By the quantity of water required in the dilution the percentage of haemoglobin in the sample of blood is obtained. The Standard Solution in the glass tube with closed ends is so coloured that it corresponds accurately to a i per cent, solution of normal blood. The graduations in the testing tube each represent a volume of 20 cubic millimetres. Thus if we dilute the 20 cubic millimetres of blood up to the 100 mark we have a i per cent, blood solution, and if the blood ha^ a normal percentage of haemoglobin, this mixture will correspond exactly in depth of colour to the standard solution. 14 -CROSS STREET • HATTOTST GARDETST E-C BAIRD &TATLOCK (LOM)ON) LTD. If this hue of the sample solution is already attained, when you have filled in water up to the line 50. the blood only has 50 % normal htemoglobine. In this way always the line to win. h tin- mixture hai to be iiluted with water gives the percentage of the tested blood in per cents, of the standard. I lie . ..iM|).m,.iii »i I .in is made in rejected light by putting both tubes in the holes of the l.K. hlv the \urums n i,.us cif the picarminic glycerin and the blood solution according to the wuy the li«ht i-. lallini; mi thrin I !»• ;hc standard solution has been specially tested for this paper shade. It t lie test is carefully made, the reiult is accurate up to about 5 %. The glass tube with white point is (or lit examinations, that with black point for artificial light examinations. A807 .\807T Haemometer, after Sahli . . DIRECTIONS FOR USE ACCORDING TO SAHLI. After the graduated glass has been rilled up to the loth division by means of the larger pipette or a droppm-- bottle with the diluted hydrochloric acid (so-called i-io standard hydrochloric acid) wlmh i- used as reagent. take from the patient by means of a lancet or Frank's fleam a drop of blood in the usual manner, of which 20 cram, is drawn up into the capillary pipette and blown into the graduated glass. By repeatedly sucking the liquid back and blowing it out again the capillary must be completely liberated from the blood taken up and the blood must be intimately mixed with the hydrochloric acid. After waiting exactly one minute until the mixture is coloured dark brown and has clear add water slowly with constant shaking to the mixture by means of the larger pipette or a droppin bottle until the mixture shows exactly the same colouration as the standard solution when placed besu latter in the ebonite stand and observed in incidental light. The percentage of haemoglobin in the b then be read directly at the division up to which water had to be filled to obtain like colouration. In ordi that the scale of the graduated tube shall not disturb and that no preconceived opinion as to the percentage of hemoglobin to be expected may come into play, it is preferable to turn the Rraduated glass so that the scale disappears behind the edge of the ebonite frame, and from the first to cover the top part of the glass witr paper during the determination. The examination can be made both by artificial light and daylight, and for specialty exact determinations preferably in a dark room with artificial' illumination employing a laryngeal lamp or a dark la 808' Hayem-Sahli Hsemacytometer, for bedside investigations (as described in Prot. Sahli's " Lehrbuch der klinischen Untersuchungsmethoden," 5th Edition, 1909, pp. 854 to i 861, 862), in case The apparatus consists of : — \ Eyepiece III with sliding eye lens and screw-in Hayem counter, including tables B Object Slide and Chamber 0.2 mm. deep, without ruling, but with reference squa of 0.2 mm. side ruled on the floor of the chambsr and surrounded by conce orientation circles C Object Slide with Chamber 0.1 mm. deep, with reference square of 0.2 mm. side surrounded by concentric orientation circles, and, in addition, a n scale, viz., i mm. divided into 100 parts i £0 17 6 £2 15 0 £0 14 0 £040 £090 BAIRD &.TATLOCK (LONDON) LTD. D. Two Pipettes for the Dihient, of 250 — 500 cub. mm. capacity, one marked " red," the other " white " .. .. .. .. .. ..each6/- E. Pipette for aspirating the blood, of 1 — 5 cub. mm. capacity, for red corpuscles, marked " red " . . . . . . . . . . . . each F. Pipette for aspirating the blood, of 5 — 25 cub. mm. capacity, for white corpuscles, marked " white " . . . . . . . . . . . . each G. Two Mixing Cells with stoppers, one marked " red," the other " white." These cells are so adapted to take to patient's bed for counting appropriately diluted blood samples .. .. .. .. .. .. .. each, l/- H. Two Thick and Two Thin Plane-parallel Cover-Glasses . . each, 6d. I. Stirring Spatulum . . . . . . . . . . . . each £0 £0 ADDITIONAL APPARATUS : J. Object Slide with Chamber 0.02 mm. deep for very high magnifications. The chamber has ruled upon its floor a reference square surrounded by concentric orienta- tion circles and a micrometer scale (i millimetre divided into a hundred parts) each £0 9 K. Automatic Limit Stop for attachment to the microscope tube . . each £0 3 L. Mechanical Stage with self checking travel in both directions, for systematically searching through the blood preparation, including case . . . . each £315 809 809' Hall's Rotary Hamoglobinometer, suggested by Arthur J. Hall, M.D., with supply of Filter paper and two needles in case . . . . . . . . . . each Extra books, per doz. DIRECTIONS. 1. Tear a slip of absorbent paper from one of the books, and holding it between the thumb and finger of the left hand, draw it out with the right, so as to give it a slightly convex surface. 2. Prick the finger or ear in usual manner. 3. Soak up a drop of blood with one end of the slip, as in the careful removal of a blot of ink. 4. Remove any excess of blood from surface of slip. 3. Insert the slip (convex surface uppermost) down the slot D, — D1 so that the part infiltrated with blood completely fills the circular opening C1 ; bend down any part of the slip which projects beyond the edge at D or D1. 6. Rotate the edge of the revolving disc A1 until the standard colour at the circular opening C most nearly matches that of the blood stain at Ct. 7. Read off the corresponding percentage at the opening on the back of instrument. N.B. — Good daylight is essential. The eye may be rested from time to time by turning the instrument and looking at the green colour at the back. £0 10 £0 1 CROSS STREET • HATTCHSr GARDETST, E-C 170 e^P 810 814 Haemacytometer, Dr. Oliver's, consisting of lancet, standard graduated tube, and 10 cubic millimetres measuring pipette . . . . . . each £212 6 117 Haemacytometer and Lymphometer combined £2 12 6 f!2T Haemodynamometer, Portable form for measuring arterial and venous blood pressure as devised by Dr. George Oliver (latest pattern) with spring slide attached, in case, and wristlet complete each £3 13 6 The blood-pressure is obtained through the intervention of a stratum of fluid contained in a small cylindrical investigation having demonstrated that the blood-pressure in man can only be accurately deter- - d through a fluid medium, a solid pad affording erroneous results because of the varying calibre of the ptencs and of the different degrees of tissue resistance over them (see " Blood and Blood-pressure " bv U M.D., F.R.C.P., London : H. K. Lewis, 1901). The graduations, in mm.Hg., have been determined by the mercurial manometer. The scale in the form a helix, or involved circles, comprises over 200 mm.Hg , and is of ample length, being at least n inches, to ruble the observer to make accurate differential readings of 2^ mm. The instrument determines the blood- ssure in the arteries and in the veins. 13T Slide for applying Haemodynamometer . . each 14' Sphygmomanometer (Tycos) after Dr. Rogers for determining both the Diastolic. and Systolic readings of Arterial blood pressure . . . . . . each The arm sleeve (Patent applied for), which contains the rubber bag for producing pressure upon the arm. made of strong and inelastic but soft and flexible cloth. It is applied by placing the rubber bag directly • the inside of the left arm, wrapping the sleeve, like a bandage, around the arm and tucking the end unclrr ic preceding fold. The pressure produced by the inflating bulb catches the end of the sleeve, holding it tight hile the observation is being taken. No straps or buckles are necessary. 'Ihc rubber bag (gj by 5 inches), in the sleeve bandage is connected with the Sphygmomanometcr gautjr »1 with the inflating bulb by two small rubber tubes. A small hook, attached to the margin of the ban.!. stains the gauge while the observation is being taken. The " Tycos " gauge measures pressure between and j'io millimetre:-, of mercury. The ilial is graduated to centimetres, half and quarter centimetres, and, by an ingenious arrangement, is cely movable, so that the index needle may always be adjusted to the zero of the scale without disturbing '. hanism. I £0 10 6 £500 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS iff 171 BAIRD &TATLOCK (LONDON) LTD. 815 817-821 815T Dr. Oliver's Clinical Mercurial Compressed Air Manometer, complete instrument, with Auditory Tambour and Visual tube . . . . . . . . . . each 816' Clinical Mercurial Compressed-Air Manometer, with Filler and Armlet Haemocolorimeters, according to Prof. Dr. W. Autenrieth and Prof. Dr. J. Kcenigsberger. The new colorimeter for determining the haemoglobin in the form of hydrochloric hematin can be easily and rapidly manipulated, its initial cost is small and it is sufficiently exact for investigations of this sort. The colorimeters constructed hitherto are either very expensive apparatus and not easy to manipulate, or can be used only for approximately determining haemoglobin. Another disadvantage of the colorimeters generally used is that the comparison solution, the hydrochloric hematin does not keep ; the colouring matter is deposited and in about one year the comparison solution is considerably weaker in colour than at the begin- ning. In the new colorimeter this drawback is removed by the hydrochloric hematin being replaced by an optically equal and durable solution. Manipulation is further simplified by its being necessary to add only once a certain quantity of the i-io standard hydrochloric acid to the blood and it can then be directly compared by shifting the wedge. In this manner one does away with diluting until uniformity in colour is reached, by which one was apt to dilute too much. The measuring is finished in about two minutes. 817T Small Colorimeter with one gauged wedge for blood testing .. .. .. each 818T Small Colorimeter with i gauged wedge each for blood testing and sugar in Urine 819T Small Colorimeter with i empty wedge with ground-in stopper, to be calibrated by the user for any kind of colorimetric examination, i.e. for the kidney diagnosis according to Rowntree-Garaghthy, Baltimore . . . . « . . . . . . each We supply the Hyson-Westcotts's fluid for the kidney diagnosis at 5/- per box of 10 ampules of i cc. each. 820T Physiological Outfit, consisting of small Colorimeter with i gauged wedge each for Hsema- tine and iron in blood, sugar, creatinin, indican, and uric acid in urine, all parts in velvet- lined, polished wooden case . . . . . . . . . . . . each 82 11 Drinking Water Outfit, consisting of small Colorimeter with i gauged wedge each for ammonia, nitrous acid, iron, and i empty wedge with stopper for any other kind of colori- metric examination, also with light protection device, all parts in velvet-lined, polished wooden case each £250 £2 10 0 £2 0 0 I £6 15 OJ £5 15 0 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &TM10CK (LONDON) LTD. 22' Drinking Water Outfit, consisting of small Colorimeter with light protection device and i gauged wedge each for ammonia, nitrous acid, sulphuretted hydrogen lead iron CODDBT and 2 wedges, all parts in velvet lined, polished wooden case . ' each' 231 Small Colorimeter for Drinking Water with light protection device, 2 troughs and r gauged wedge each for ammonia, nitrous acid and iron (without case, etc.) each 24' Chemical Colorimeter, with only one gauged wedge (or either chromium, copper, titanium manganese, vanadium, iron, iodine, or copper, large mode- . . 25 ! 26 each Chemical Colorimeter, large model, with one empty stoppered wedge of 16 cm to be calibrated by the user . . . . . . . . e'ac)j Chemical Outfit, consisting of small Colorimeter with 12 cm. gauged wedge- i•'•••• • •'••"• •• • • Counting Chamber. 849 eacli CROSS STREET • HATTQN GARDEN, E-C 176 r* BAIRD &.TATLOCK (LONDON) LTD. 858 Thoma's Haemacytometer, by Leitz, consists of an object glass with carefully constructed cell, a ground absolutely plane cover-glass and two pipettes for mixing the blood and saline solution used in the examinations. One of these pipettes, for estimating the number of red corpuscles, is so graduated as to permit dilution of the blood 100 or 200 times as required ; the other, for counting the white corpuscles (leucocytes), is graduated for dilution of the blood 10 or 20 times .. .. .. .. .. each £1 50 A full description is supplied with each instrument. >5' Mixing pipette for white corpuscles, diluting I in 10 .. .. .. „ £040 56T ,, „ red ,, ,, i in 100 . . „ £040 >7T Slide with cover-glass .. .. .. .. .. .. .. „ £0 13 0 The volume contents of the pipettes are most carefully determined, and the depth of the cell established by accurate micrometric measurement, thus permitting very exact observations by cans of this instrument. >8T Apparatus for the Clinical Determination of the Alkalinity of the Blood (after C. S. Engel — a modification of the method of Lowy and Zuntz). The following parts compose the apparatus : — 1. A capillary pipette so graduated as to permit the dilution of 0.05 cubic centimetre blood from the finger up to 5 cubic centimetres with distilled water. 2. A beaker for the reception of the diluted blood. 3. A burette of 10 cubic centimetres capacity, mounted on a stand, each cubic centimetre having 20 divisions on the scale. Full directions for the use of this apparatus accompany each outfit. Price, in box .. each £1 00 . 59T Ehrlich's Eyepiece, provided with a diaphragm having a square opening, the size of which is regulated by a small lever. This eyepiece is designed to facilitate the estimation < relative numbers of red and white blood corpuscles in dry preparations Full directions accompany each instrument. each £1 10 0 iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 177 BAIRD & 1ATLOCK. (LONDON) LTD. 862 866 869' Haemacytometer, Miescher's (Zeiss). Counting chamber in combination with a specially constructed mixing pipette. With principal gauge marks for dilutions of y^, p^, -s^Tll and auxiliary marks for accurately estimating any existing faults in the graduation. In case 861' Mixing pipette alone . . . . . . . . . . . . . . each 862' Fleischl's Haemoglobinometer for ascertaining the amount of haemoglobin contained in the blood. This apparatus possesses the following points of superiority : 1. The instrument is convenient and easy to manipulate. 2. It is adapted for determining the relative proportion of haemoglobin with rapidity and precision. 3. A very small quantity, viz. a single drop of blood suffices to perform the determination. 4. It is of an almost unlimited durability. Complete directions are supplied with each instrument . . . . . . each 863' Six spare capillary tubes . . . . .'.' . . . . . . . . ,, 864T One spare comparison chamber (When ordering extra capillary tubes the number stamped on metal holder must be given, as each instrument is calibrated to suit capillary tubes of a definite capacity). 8651' Round yellow glass as suggested by Liebermann, for using the haemoglobinometer with daylight . . . . . . . . . . . . . . . . each 866T Prof. Miescher's Modification of Fleischl's Haemoglobinometer, for ascertaining the absolute, as well as the relative, percentage of haemoglobin . . . . . . each 867' Pocket Haemoglobinometer 868 868' Puncturing Apparatus for using with the haemometer, designed by Dr. Laker CROSS STREET • HATTOTST GARDElSf, E-C 178 BAIRD &TXTLOCK (LOM)ON) LTD. . *• ^ .ftr, 1 r m 869 870 871 8691 Glycosometer, Gerrard's, with porcelain dish, clamp and stand . . each This instrument consists of a burette graduated to read the percentage of sugar, or graius per ounce, in urine, without the need of any calculation. The ordinary method of analysis is em- 1 'loved, and the whole process is so simple that it can be performed with ease in a few minutes. The Apparatus is recommended in Halliburton "s " Physiological Chemistry," Scott's " Manual of Urine Testing," and is used in many Hospitals, and by eminent physicians. DIRECTIONS FOR USE. Take cither 10 drachms or 10 c.c. of urine found to contain sugar, and dilute with water until it measures loo drachms or 100 c.c. Mix well. Now fill the Burette to the zero line with the diluted urine. Next introduce I 10 c.c. (2| drachms) Fehling Solution, and 40 c.c. (10 drachms) water into the porcelain dish and boil. Whilst boiling, run tho urine from the Burette into the dish in a slow stream until the blue colour has gone from the Ft-hling. The operation being finished, the level of the urine shows the percentage of sugar present, and the equivalent in grains per ounce is found by reference to the annexed table. NOTE. — The Instrument is graduated to read percentages of sugar between 10 and i, but should urine contain more than 10 per cent., then dilute 10 volumes to 200 with water, proceed as before, and multiply the '•I'M rvcd percentage by 2. If there is less than i per cent, sugar, use undiluted urine, test as before, then divide the reading by 10. TABLE SHOWING THE PERCENTAGE EQUIVALENT IN GRAINS PER FLUID^>UNi K Percentage. 10. o .. 9-5 •• 9.0 .. 8.5 .. 8.0 .. 7-5 •• 7.0 .. 6.5 .. 6.0 5.5 .. 5.0 .. 4-5 •• 4.0 .. 3-5 •• 3.0 .. 2.5 .. 2.0 Grains per Fluid Ounce. .. 43.75 •• 4!-55 .. 39.4 .. 37.2 .. 35.0 •• 32-8 ..30.6 ..28.45 . . 26.25 .. 24.05 .. 21.9 •• 19-7 .. 17.5 •• 1.5-3 .. 13.1 .. 10.95 8.75 Percentage. .9 Grains per Fluid Ounce. 8-3 7-9 7-45 •• 7.0 6-55 6.1 5-7 5-25 4.8 4-4 3-95 3-5 3-°5 2.6 2.2 '•75 8701 Pipette, with quartz needle, devised by Dr. Griinbaum, for the estimation of bile salts each 'See description in Transactions of the Pathological Society of London, vol. lv., part i, 1904.) A. Shows the manner in which the drop falls if needle is clean. B. Shows the manner in which the drop falls if needle is greasy. £0 12 0 £056 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 871 T Clinical Viscometer, for taking viscosity of blood. Full particulars as to use sent with each instrument. Price tube only (see page 179 for illustration) £036 Extras : 872T Price per set of 6 tubes, marked with time value in case 873T Stop Watch £1 2 6. £1 I 0 874T One complete set consisting of 6 capillary tubes, each tube marked with the time value for water ; stop-watch (which is started, stopped, and restored to zero by pressure of the finger) ; bottle containing 6 Wright's lancets ; metal holder and heater for the tubes ; small force pump, rubber tubing, and clearing wires ; table for readily finding blood viscosities relative to water £2 10 0 Fig. i. — Determination of the area of the blind-spot arranged for use with the right eye. 875 Fig. 2. — Showing the reverse side of the instrument. 875 875T The Colour Blind Margin of the Blind-spot, and the Scotometer, by John Berry Haycraft, M.D., D.Sc., Professor of Physiology, University College, Cardiff . . £5 5 The observer rests his chin on one of the curved surfaces (2) which may be raised or lowered by the screw (3) ; his left eye being closed he looks with his right eye through the metal ellipse (i) at the white mark on the black metal plate. The white head of the nail, which is placed in the metal hole to the right of mark is then in the blind-spot and is invisible. By means of the screw (4) the nail head can be raised or lowered. The screw is turned until the nail head becomes visible. As soon as it is visible the nail head is pressed, and this records its position in the way to be described presently. Thus the length of the blind-spot in a vertical direction is recorded. The screw (5) is then loosened. When this is done turning screw (4) produces a horizontal movement of the nail head. The screw (4) is then turned each way until the nail head becomes visible, and the length of the blind-spot in a horizontal direction is registered. The extent of the blind-spot in other vertical or horizontal directions can be registered in a similar manner, and the area of the blind-spot marked out. In making observations with the left eye the plate is rotated so that it projects on the left side of the instrument. The recording of the position of the nail head is effected as follows : — A transfer paper (A), and a paper ruled in square millimetres (B), are placed in the flat box, which is closed by the door (D). The point of the nail projects from the centre of the tube (c), so that when the nail head is pressed it marks a dot upon the ruled paper. A line joining the dots obtained in the manner given in the preceding paragraphs gives the area of the blind-spot. The blind-spot may, with this instrument, not only be mapped out accurately, but the larger blood-vessels entering, and leaving it, may also be noted, and mapped out for a short distance in their course. CROSS STREET • HATTON GARDEN, E-C- 180 RT E BAIRD &TATLOCK (LONDON) LTD. ll.i-iii:itx F. Solutions for Milk testing, A and B . . two bottles 17s High-Speed Medical Centrifuge, geared for two speeds, with one pair graduated blood tubes d, one pair urine tubes, b, one pair plain tubes c, one pair graduated milk tubes, for human milk A, one pair sputum tubes, two pairs plain cylinder tubes, with holder haematocrite and aluminium carriers, in polished mahogany case . . . . each (Price of extra tubes, see above). INSTRUCTIONS FOR USING CENTRIFUGES (Nos. 876 and 877). These instruments have been devised for the rapid separation of urine, blood, pus, milk, etc. They run : jly, and a speed of 2,000 revolutions per minute can easily be obtained. The tube holders and hxmatocrite Eachment are made of aluminium to ensure lightness. BLOOD EXAMINATION. — The finger of the patient, after being cleansed, is punctured with a needle, the first jp of blood is rejected, and the second obtained by a slight pressure. This sample is drawn by suction into £3 15 0 £0 £0 £0 £0 £0 £0 17 17 2 14 0 2 £440 JCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIR.D &TATLOCK (LONDON) LTD. the capillary blood tubes ; these arc placed in the haomatocrite frame, and the handle attached to the high-speed spindle when the tubes can be rotated at a speed of 5,000 revolutions per minute. This process is simple and rapid — the blood does not have time to coagulate, and by centrifugal force the red corpuscles are thrown to the end of the tube, and will occupy about half the tube, or to the mark 50. The white corpuscles being next in specific gravity, will occupy a position between the red corpuscles and liquor sanguinis, which is found in the proximal end of the tube, quite clean and free from corpuscles. URINE EXAMINATION. — Specially graduated percentage tubes are supplied tapering to one end, and these are revolved about 2,500 times per minute. This speed is quite enough to precipitate even the hyaline casts without breaking them or altering their form. SPUTVM EXAMINATION. — A small quantity of sputum is stirred in a porcelain dish until it is apparently homogeneous ; two small tubes are then filled, placed in h;ematocrite frame, and revolved for three minutes at a speed of 5,000 revolutions per minute. The solid portion can then be transferred to slides for microscopical examination. IN WORKING WITH SMALL QUANTITIES, where the micro-organisms are few, two large sediment tubes are used, and after the sediment has been precipitated, the greater part of the liquid is decanted, and the remainder transferred to small tubes for final examination at high speed in the haematocrite frame. MILK EXAMINATION. — 5 c.c. of milk are placed in each bottle by a pipette, i c.c. of Solution A added, and well shaken. Then by another pipette Solution B is added by drops until the bottles are filled to the zero mark on neck, the bottles being well shaken in the meantime. They are now placed in the buckets and whirled for about one or two minutes, after which the fat rises to the top of the graduation, and can be read off in direct percentages. If the milk is richer than 5 per cent., add an equal quantity of water, mix thoroughly, and multiply the result by two. SOLUTION A. SOLUTION B. Fusel Oil ... . . . . 37 parts by volume. Sulphuric Acid Wood Alcohol . . . . i 3 „ „ Distilled Water Hydrochloric Acid . . 50 ,, „ 50 parts by volume. 5° Haematocrite. 878 878 879 878s Centrifugal Machine, witli two buckets and haematocrite, for separation of blood, urine, etc. with clamp for fixing to table, with two graduated tubes for urine, and two capillary blood tubes . . . . . . . . . . . . . . . . ..£250 879s Centrifugal Machine, with two buckets, arranged to be driven by high water pressure, for the separation of urine, milk, etc., with four plain tapered tubes .. .. .. .. £2 10 0 CROSS STREET • HATTON GARDE1ST, E-C 182 8SO-881 Centrifugal Machine, with aluminium buckets to carry tapered glass tubes, holding about 15 c.c. each, for urine analysis, etc., and ruematQcritc arrangement for blood analysis ; mounted on wood base, with adjustment for tightening belt, with two tapered plain, two tapered graduated tubes for urine, and two graduated bl'xxl tube-. >805 Price, with electromotor and starter, mounted on same sole with two buckets each £7 10 0 181s Price, with electromotor and starter mounted on same sole with four buckets .. £8 5 0 When ordering please give voltage of electric supply, and state if continuous or alternating. 882-883 <82- Centrifugal Machine, as above arranged with two buckets, but fitted with guard each £850 J83- Centrifugal Machine, as above, arranged with four buckets, but fitted with guard ,, £900 When ordering please give voltage of electric supply, and state if continuous or alternating. 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 183 BAIRD &. TATLOCK (LONDON) LTD. 884-886 Martin's Water-Driven Centrifuge, designed by Dr. C. J. Martin, Director of the Lister Institute of Preventive Medicine. This Centrifuge consists of a plate with four radiating chambers (see illustration above), each having a depth sufficient to take a tube and its necessary holder flush with the under surface of the plate, thus avoiding all atmospheric resistance. The plate is fitted to a spindle, pivoted between an upper and lower centre, and the spindle carries at its lower end a small water-wheel in a " well " to which are attached the nozzle or nozzles and fittings for connecting with the water main and for carrying off the waste water. The upper centre is poised lightly to avoid friction, and is mounted in a flexible holder, thus giving the necessary freedom from strain when working at high speeds. Throe plates are provided, carrying tubes of 25 c.c.. 10 c.c., and 5 c.c. capacity respectively ; when only a low pressure is available the smallest plate will probubly be the more suitable. The speed has been carefully measured, and a rotation of from 2,000 to 6,500 per minute can be maintained with, ordinary pressure and with absolute safety. DIRECTIONS FOR FIXING, AND FOR THE USE OF CENTRIFUGE. 1. See that the table or bench to which it is to be fixed is carefully levelled. 2. When the "well" is screwed down and before the cover is replaced, the point of the jet must be adjusted to within about J inch of the motor wheel, and fixed in position by the counter nut ; then connect with the supply and see that there is no obstruction. 3. Replace the well cover and plate carrying the tube holders ; then bring the upper centre into position, taking care that it is so lightly poised over the spindle that practically there is no friction during rotation, 4. LUBRICATION. It is absolutely essential to the perfect working of the Centrifuge that the centres should be daily and regularly lubricated before use ; also that the oil tube and gravity cup should be kept well supplied while in constant use. The heavy petroleum oils as used for gas engines are the most suitable. 5. The plate, when working, must always be equally balanced, i.e., the tubes must lie used in pairs and not singly. 6. In attaching the waste pipe take care that it is never less in diameter than the outlet — i inch iron barrel for the single jet and li inch for the double jet. 7. In the case of a Double Jet Apparatus with high pressure, it is of advantage to fit a stop-tap so that one of the jets can be cut off when the small size plates are in use. Machines with single jet for high pressures. 884' With 5 c.c. brass plate, four tube holders and twelve glass tubes 885T Witli 10 c.c. brass plate, four tube holders and twelve glass tubes 886T With both 5 and 10 c.c. brass plates, eight tube holders and twenty-four glass tubes each £550 £560 £6 16 0 14 • CROSS STREET • HATTOTST GARDEN, E-C BAIRD &WLOCK (LOM)ON) LTD. 887-890 Machines with double jet for low pressures, plates of light alloy, instead of brass as used for high pressures. S7' With 5 c.c. plate, four tubeholders and twelve glass tubes . . each * With 10 c.c. plate, four tube holders and twelve glass tube* . . |89T With both 5 and 10 c.c. plater., eight tube holders and twenty-four glass tubes . . . 90T With 5 c.c., 10 c.c. and 25 c.c. plates, twelve tube holders, and thirty-six glass tubes L9F Extra glass tubes for use with above . . 5 10 25 c.c. Price .. 1/6 1/10 2/3 per dozen. With very low pressures or in cases in which unusually rapid revolutions arc required it is advisable to ivc the plates, more especially the larger ones, in alloy instead of brass. A Pressure Gauge is indispensable to the comfortable working of the apparatus in consequence of the pressures. Diminished speed is often attributed to some fault in the apparatus, when it is in reality lailure of pressures. Price of Gauge . . . . . . . . . . . . extra £0 13 6 891T Martin's Centrifuge, electrically driven. When, owing to low water pressure, or, as in large institutions, a iluctuation of pressure, the water-driven ,:ilnnc is found unsuitable, the electrically-driven becomes the natural corollary, and the latter pattern of M.irtin, fitted with Dr. Sydney Rowland's clutch, has proved the greatest success. As in the water-driven ittcrn. it l.as the upper centre mounted in a flexible holder, and is fitted with properly adjusted lubricators. j- supplied with a suitable motor with a three-speed pulley, which enables reliable speeds of 2,000, 4,000, .d (1,000 revolutions per minute to be steadily maintained. If the motor is not of sufficient power, it must be borne in mind that its initial speed becomes reduced hou the larger pulleys are used. As the result of an extended experience it is recommended that the motor should not be of less power an ; 1 1.P., and that a regulating switch of good construction should always be included in the outfit ; also that lotor, switch, and centrifuge should be mounted on a base of either polished slate or teak wood, and that space •nild ;ilsn be left on the base for the fixing of a shaker if required. It is essential that the nature of the current should be stated, the periodicity and oltage given. Martin's Centrifuge with Motor (J-H.P.) and Controlling Switch, mounted on polished slate base, with runners for adjustment of band. 891 • For no volt current, fitted with 10 c.c. brass plate . . each 891- ditto ditto fitted with 25 c.c. brass plate .. „ '891 ' For 220 volt current, fitted with 10 c.c. brass plate .. „ ;891' ditto, ditto, fitted with 26 c.c. brass plate .. .. „ 891 r Watkin's Switch .. extra £519 0 £610 £7150 £11 20 £14 0 0 £1412 0 £1410 0 £15 2 0 £012 6 BAIRD &.TATLOCKL (LONDON) LTD. 892 892T Centrifuge, Westminster Model, designed by Mr. F. K. Chopping. The centrifuge is mounted on a heavy iron tripod base; and the vertical shaft runs on ball bearings. The horizontal arm carrying the tube holder is also provided with ball bearings and bv arrangement of the Governor Balls at side has a tree wheel action in both directions, thus ensuring a gradual starting and stopping movement. Machine is strongly made, is quiet and smooth in action and can be run at a speed up to 3,000 revolutions per minute. Price, without motor, for two tubes, each 20 c.c. capacity Centrifuge, exactly as above, but with arm carrying buckets for 4 tubes, each 20 c.c. capacity Electric Motor and Starter, suitable for above . . . . cxtra 893 894-895 (Registered No. 536815). ' Centrifuge, Registered Pattern, to carry four tubes, on heavy mahogany base, with motor and starter resistance. This centrifuge is solidly constructed to run at a maximum speed of 3,500 revolutions per minute. The revolving head is mounted on a vertical steel driving shaft which runs between four sets of steel ball bearings, two sets of bearings carry the load while the other two prevent side move- The head is enclosed in a spun copper guard (with movable cover) to reduce the air resis- tance. Machine should be mounted on a steady platform or table and securely fixed to prevent any possible vibration. 894T Centrifuge, as above to carry four tubes, each 25 c.c. 895T Centrifuge, as above to carry four tubes, each 50 c.c. Electric Motor, J H.P., and Speed Regulating Starter, no voltage release type for use with above . . . . . . . . . . _ _ ' ' extra If motor is required for alternating current, a countershaft is required .'.' price extra Please state voltage and nature of current when ordering. £10 5 £12 10 £6 6 £17 £19 £12 £2 10 10 5 18 0 0 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. 896-897 Centrifuge, adapted to be run by electro motor, mounted on solid mahogany l>u.>c. with t-lectro motor, and starter. The buckets hang vertically when the machine is a; n-,t. and are protected by the revolving cover when in motion. Please state voltage and nature of electric current when ordering. 196' Machine, to carry four buckets with tubes of 10 c.c. each, complete with motor and starter 1 <97' Machine, as above, but with four buckets and tubes for 20 c.c. „ „ „ „ each £10 15 0 £12 15 0 898 98T Centrifuge, Electric. In this pattern a motor with a strong spindle is employed and adapted to run vertically. The spindle is fitted with a special carrier to take four 10 c.c. buckets. and is provided with a spun aluminium guard, which reduces the air resistance and also serves as a guard for the buckets when in motion. This guard is screwed down on spindle and revolves with buckets. Price, complete, mounted on board with plug switch and starter resistance .. .. .. cacl' £l° I0 ° Please state voltage and current when ordering. CHEMICALS. BAIRD &. TATLOCK (LONDON) LTD. 899 and 902 With protecting mantle removed showing metal carrier in position. (Registered No. 536815.) 899 and 902 899' Centrifugal Machine (Registered design Xo. 536815) as constructed by us to the order of Metropolitan Water Board and Metropolitan Asylums Board, etc., to carry eight glass vessels, each of 100 cubic centimetres capacity. Price of machine only . . each £36 900' Electro-Motor for continuous current, i H.P., with starter, suitable for above machine ,, £12 0 901T Safety Guard of stout wood, lined with -J-in. sheet iron, with movable hinged cover to top for easy access to centrifuge, suitable for above machine . . . . . . each £5 0 902' Centrifugal Machine (Registered design Xo. 536815), similar to Xo. 899, but arranged to carry eight glass vessels of 200 cubic centimetres capacity. Price of machine only each £42 903' Electro-Motor for continuous current, with starter, cut-outs, switch and slide rails, for fixing motor, suitable for above machine . . . . each £14 1( 904' Safety Guard of stout wood, lined with -J-in. sheet iron, with movable hinged cover to top for easy access to centrifuge, suitable for above machine . . . . each £5 If electro-motor is required, suitable for use with alternating current, we can supply a counter- shaft with fixed or loose pulleys at an additional cost of £4. When ordering please state voltage of electric supply, and, if alternating, the periodicity. For description see next page. CROSS STREET • HATTON GARDE1ST, E-C - m. • Motor with starter, for driving Centrifuges 899 and 902. SPECIFICATION OF MACHINES (Nos. 899 ami 902). The machines are constructed to carry eight nickel-plated metal buckets spun from sheet and fitted with steel collars having horizontal axis. The buckets hang vertical when at rest. F.ach bucket is fitted with heavy glass vessel capable of holding too cubic centimetres or 200 cubic ccnti- Thc revolving head is fitted with a spun copper guard to reduce air resistance ; this copper guard :* lovable cover to allow easy access to buckets. The revolving head is mounted on a vertical steel driving •, Inch is furnished with four sets of ball bearings ; two sets of ball bearings carry the load of machine. 1 the other two sets prevent side movement. Tin- lower part of steel revolving shaft carries the driving pulley, and the extreme end is mounted on a VnNiVp. ball bearings. I lie hi< lion is thus reduced to a minimum, and the machine can be run at a speed of 3,500 revolution* "iiite lor two or three hours without any of the bearings becoming unduly warm. The load is taken at ugles to the axis of rotation of the balls, and a perfect rolling action is the result. The entire machine is mounted on a solid cast-iron base with dome-shaped upright. Machine should be i.xed on an absolute steady base and bolted in position. A concrete bed in which the holding plates and bolts ire fixed is preferable. By this means the machine may be run at full speed without setting up any speed V lill.ltlc.il. h machine before being sent out is t"sted fully loaded at a speed of 4,000 revolutions per minute for hours, but machine in use should not exceed 3,500 revolutions per minute, otherwise the glass vessels ire liable to be crushed. BAIRD & lATLOCK. (LONDON) LTD. 899 and 902 \\ith pru (Registered No. 536815.) nuLutle remo\'cd showing metal can't- ;^ in position. 899 and 902 899' Centrifugal Machine (Registered design No. 536815) as constructed by us to the order of Metropolitan Water Board and Metropolitan Asylums Board, etc., to cany eight glass vessels, each of 100 cubic centimetres capacity. "Price of machine only .. each £36 0 0 900' Electro-Motor for continuous current, J H.P., with starter, suitable for above machine „ £12 0 0 901T Safety Guard of stout wood, lined with -J-in. sheet iron, with movable hinged cover to top for easy access to centrifuge, suitable for above machine . . . . each £500 902r Centrifugal Machine (Registered design No. 536815), similar to No. 899, but arranged to carry eight glass vessels of 200 cubic centimetres capacity. Price of machine only each £42 0 0 903' Electro-Motor for continuous current, with starter, cut-outs, switch and slide rails, for fixing motor, suitable for above machine .. . . .. each £14 JQ Q 904 ' Safety Guard of stout wood, lined with -J-in. sheet iron, with movable hinged cover to top for easy access to centrifuge, suitable for above machine . . each £500 If electro-motor is required, suitable for use with alternating current, we can supply a counter- shaft with fixed or loose pulleys at an additional cost of £4. When ordering please state voltage of electric supply, and, if alternating, the periodicity. For description see next page. CROSS STREET • HATTON GARDEN, E-C 188 BAIRD &TATLOCK (LOM)ON)LTD. rasiaiti Motor with starter, for driving Centrifuges 899 and 902. SPECIFICATION OF MACHINES (Nos. 899 and 902). The machines are constructed to carry eight nickel-plated metal buckets spun from sheet brass, and fitted with steel collars having horizontal axis. The buckets hang vertical when at rest. Each bucket is fitted with heavy glass vessel capable of holding too cubic centimetres or 200 cubic centi- metres. The revolving head is fitted with a spun copper guard to reduce air resistance ; this copper guard lias a movable cover to allow easy access to buckets. The revolving head is mounted on a vertical steel driving shaft which is furnished with four sets of ball bearings ; two sets of ball bearings carry the load of machine, anil the other two sets prevent side movement. The lower part of steel revolving shaft carries the driving pulley, and the extreme end is mounted on a footstep, ball bearings. I lie friction is thus reduced to a minimum, and the machine can be run at a speed of 3,500 revolutions per minute for two or three hours without any of the bearings becoming unduly warm. The load is taken at rijjht angles to the axis of rotation of the balls, and a perfect rolling action is the result. The entire machine is mounted on a solid cast-iron base with dome-shaped upright. Machine should be fixed on an absolute steady base and bolted in position. A concrete bed in which the holding plates and bolts are fixed is preferable. By this means the machine may be run at full speed without setting up any speed vibration. Each machine before being sent out is t"sted fully loaded at a speed of 4,000 revolutions per minute for several hours, but machine in use should not exceed 3,500 revolutions per minute, otherwise the glass vessels are liable to be crushed. BAIRD &TATLOCK. (LONDON) LTD. 905 (Keg. No. 601,879.) The " Westminster" Vaccine Shaker, a New Pattern Shaking Machine, for vaccines, as devised by Mr. F. R. Chopping, Westminster Hospital. A new Shaker expressly designed for quiet and smooth working. It is practically noiseless and has been proved to be highly efficient. The apparatus consists of a carrier or tube holder, with a rigid arm connected at its other end to a large phosphor-bronze ring mounted on an eccentric, fixed to a small countershaft. The carrier is supported on a rocker with bearings top and bottom, and the countershaft is driven by a small electric motor controlled by a regulator switch. All bearing parts are adjustable, although actually very little wear takes place. The whole apparatus is mounted on a polished board and is very compact. 905 r Complete on stand with starter resistance motor, and shaker, arranged for continuous currents 906T Vaccine Shaker, as figured below, without motor and starter, mounted on board each Please state voltage when ordering. £6 £3 906 907 907T Shaking Machine, as No. 906, without motor, but fitted in small incubator, specially made with two tubulures for connecting to motor outside. Incubator similar in all respects to No. 294, and fitted with capsule to regulate at 37° C. Inside size of Incubator 14 in. by 12 in. by 12 in. ... .. .. each £1210 0 CPJOSS STREET • HATTOTST GARDEN, E- C *3^$ BAIRD &L TXTLOCK (LOM)ON) LTD. 908-909 Heinrici's Hot-Air Motors. DESCRIPTION. All motors are supplied mounted ready for use, and should be iirmly fastened in position so that the motor is immovable even when running at maximum speed. The motor is an air machine and therefore devoid of danger. The principal parts are — A. The Fire-pot. B. The Working Cylinder. c. The Pisplacer. The bottom of the fire-pot is heated by a small burner ; the expansion of air thus produced sets the dis- placer placed inside in motion. The warmed air is cooled in the upper part of the machine, which has the effect of suction on the piston of the working cylinder so that it is drawn back into the outer cylinder. This explains the rotating motion of the shaft. All the parts where friction occur must be lubricated by a drop of bone-oil before being set in motion. About two minutes after the burner has been lit turn the flywheels slowly round until the power generated by the hot air in the machine takes effect. The motor will then run as long as the burnei is alight. Should the machine at first work irregularly (jump), loosen the compression screw on the cylinder a few turns and screw it up lightly again as soon as the motion becomes regular. The larger the flame the quicker the motion of the machine. When the machine has long been unused, or when it has run for several consecutive hours, repeat the oiling as above directed. In order to preserve the machine apply a little petroleum occasionally to the oiled parts in order to loosen any oil that may have become hard, but the machine must not be taken to pieces. If the machine runs slower than at first, it is caused by the lubricating agent having become thick and sticky. This is remedied by a few drops of petroleum. After using petroleum revert to bone-oil. For small sizes petroleum only must be used and no fatty oil. I • Bore 40 54 65 80 100 130 m/ms. Power & 41o & & 1 i H.P. Mean Revolution Rate at which motor) should work 480 350 300 250 200 200 R.P.M. Diameter of Flv-VVheel 169 2O2 257 322 409 548 m/ms. Diameter of V Shape Pulley Grooves 37 48 65 8S no 90 1 20 MS 120 HO I6S I25 '55 I So •• m/ms. Height of engine 56 68 78 94 116 148 c/ms. Floor Space required 24 x 24 28 x 28 29 x 29 33 x 3347 x 47 65 x 65 c/ms. Approx. Weight 15 25 35 68 120 248 kilos. 908s Complete with gas burner £ s. d 476 £ s. d £ s. d. 5 12 67 15 0 £ s. d. £ s. d. 11 17617 150 £ s. d 32 0 0 909' Complete with Methylated Spirit Lamp 476676 8 17 6 13 0 0 18 7 6 BAIRD ^IXTLOCK (LOTMDON) LTD. 910 911-913 9101' Thirlmere Water Motors, suitable for driving light shafting for recording drums, stirring and shaking apparatus, etc. Horse Powers, Speeds, and Consumption per minute at various pressures. Bore of Inlet. ins. Dia. of Pulley ins. DIMENSIONS. Price * Extra t ir easy working Regulating Valve and Lever, for Org.m Blowing, &c. 20 Ibs. or 46 feet. 40 Ibs. or 93 (eet. SO Ibs. or 185 feet. Height in ins. Width in ins. Size H.P. Speed. Galls. H.P Speed. Galls. H.P. Speed. Galls. ooo oo o I •007 •0125 •03 •°5 1400 1 200 800 600 .5 3-5 6'3 •025 •04 •i •2 1900 1600 1 200 800 IT 2'2 5 9 •05 •09 '3 •6 2700 2IOO 1600 1 200 i 6 3 7 I2'5 [ it r* *i 3 M 14 16 20 7 7 8 9 £ s. d. 1 0 0 150 200 300 £ s. d. 0 10 0 0 10 0 0 12 6 0 15 0 The " Robinson " Patent Hot-Air Engine, English make, does not require water-jacket. This engine has now been on the market several years, and is thoroughly established as a success for all purposes requiring small motive power. It is absolutely reliable, and needs no skilled attention. The power is obtained by expansion and contraction, due to the alternate heating and cooling of the air confined in air- chamber. There is no internal combustion or ignition in the cylinder, so that the parts are not subjected to a severe shock, but a steady outward and inward impulse is given to the piston at each revolution of the engine. Regular working is thus obtained with a minimum of friction. The engines are worked with great economy. When started they require no attention for long periods, and then only for oiling. Prices and particulars of Nos. 64, «4. and 4 engines : — Diam. Dimension Approxi- Size No. of Cylin- der mate Weight. Cwts. Power. Revolutions per minute. Price with Gas Burner. Height. Length. Width. in. ft. in. ft. in. ft. in. ft. Ibs. per minute. 91 1T 64 4i I 6 i 9 I 2 I 750 (TV brake H.P.) 200 to 250 £850 912r «4 4i I II 2 0 I 3 I.\ 1,500 y.f „ ) 1 80 to 230 £12 0 0 913' 4 51 2 8 2 3 2 O 2.1 3,000 (JT „ ) 150 to 210 £17 5 0 For Electric Motors, see Chemical Apparatus Section. -CROSS STREET • HATTOTST GARDETST, E- C 192 BAIRD &TATLOCK (LOM)ON) LTD. IV & MICROSCOPICAL V Microscopes Bausch £r Lomb i Crouch Leitz Reichert Swift Watson Zeiss Slides. Cover Classes, and Slide Cabinets Dissecting Sets Forceps, Needles, Scalpels, etc. 254-269 242-245 193-221 246-253 273-284 270-272 222^241 285-295 295-304 305-320 14. CROSS STREET, HXTTON GARDEN, E.G. BAIRD & TXTLOCK (LOM)ON) LTD."! Catalogue. Those marked * are also printed separately. Section No. 1.* Laboratory Fittings Bacteriological Apparatus Chemical Physiology Apparatus Microscopes and Microscopical Accessories Balances and Weights Chemical Apparatus Botanical Apparatus Gas Analysis Apparatus Milk Analysis Apparatus Refractometers Oil Analysis Apparatus Water Analysis Apparatus Cement Testing Apparatus Leather Testing Apparatus Paper Testing Apparatus Physico Chemical Apparatus Pyrometers Calorimeters Seed and Soil Analysis Apparatus Spectroscopes and Polariscopes Volumetric Apparatus Anatomical Models Meteorological Apparatus Assay Apparatus 3. 4.* 5.* 6.* 7." 8. 9.* 10. 11." 12. 13. 14. 15. 16. 17.* 18.* 19.* 20.* 21. 22. 23. 24. 25.* Chemicals Pages Nos. 14.56 57-161 162^192 193-320 32 1, 382 383-816 817-842 843^886 887^894 895 - 90 903^92 927^93 934^94 947-949 950^951 952-976 977-1006 1007-102 1023-104 1043-107 1079-1087 1088-1105 1106-1124 1125-1172 1187-1246 /o !2 ! CROSS STREET- HATTCTN GARDEN E- C BAIRD &TATLOCK. (LONDON) LTD. SECTION No. 4. Microscopes and Accessories, Microtomes, Dissecting Instruments, 6?c. LEITZ'S MICROSCOPES, MICRO-PHOTOGRAPHIC APPARATUS, ACCESSORIES, &c. The undermentioned Microscopes arc manufactured by Ernst Leitx, Wetzlar, the celebrated maker of these instruments. They are sold at his catalogue price, and each part is constructed by that firm, including stands, etc. Full Catalogues will be supplied on application, but the following Sets are suggested. Leitz's Microscope Diagram as above, coloured, size 44 by 28 in., will be sent for demonstrations, to educational institutions, on application. BAIRD &TATLOCK. (LONDON) LTD. 914-918 STAND A. UNIVERSAL MICROSCOPE. 9141 Large Microscope (Leitz). Inclinable, with hinged joint and clamping lever, circular revolving and centring stage, coarse adjustment by rack and pinion, new continuous safety micrometer movement with divided drum (each division = 0.002 mm.), wide tube adapted for photo-micrographic work witli wide-angled lenses without eyepieces, draw- tube with millimeter scale, large substage with hinged three-lens condenser of N.A. 1.40 and cylinder iris diaphragm ; large mechanical stage No. 1023 for objects measuring up to 100 by 50 mm. ; triple nosepiece, drawing eyepiece No. 1035 ; apochromatic objectives 16, 8, 4, 2 mm. oil-immersion N.A. 1.32 ; compensating eyepiece, 4, 8, 12, 18 ; compensating micrometer eyepiece 6 ; magnifications 64 — 2300 . . each £52 2 0 CROSS STREET • HATTOTST GARDEN, E-C 194 BAIRD &TATLOCK (LONDON) LTD. 915' Same Stand, with Substage (a), large mechanical stage, No. 1023; triple nosepiece ; achromatic objectives, i. 3, 4, 5 ; fluorite objectives 7a, 8, 9, ^a oil-immersion, N.A. 1.32 and TV oil-immersion N. A. 1.32 ; huyghenian eyepieces, O, I, III, IV, V micrometer eyepiece II ; magnifications 13—1400 . . . . . . . . . . each £47 5 0 916' Same Stand, with Substage (a) ; Triple nosepiece, objectives 2, 4, 6a*, ft oil-immersion N. A. 1.30 ; eyepieces, O, I, III, IV, V ; magnifications 23 — 1260 .. .. each £26 5 0 917' Same Stand, with Substage (a) ; triple noiepiece, objectives 3, 72*, N. A. 1.32 ; eyepieces, I, III, IV, V ; magnifications 51 — 1176 .. oil-immersion, .. each £26 5 0 918' Stand with Substage (a), exclusive of objectives, eyepieces, and nosepiece . . each £15 0 0 This stand may, if preferred, be supplied with a horseshoe foot similar to that of stand B. 919-923 STAND B. 91 9T Large Microscope B (Leitz). Inclinable, with hinged joint and clamping lever, with circular revolving and centring stags. Coarsf adjustment by rack and pinion, new continuous safety micrometer movement with divided drum (each division = 0.002 mm.). Draw-tube with millimetre scale. Large substage with hinged three-lens condenser of N.A. 1.40 and cylinder iris diaphragm; mechanical stage, No. 1024; triple nosepiece; objectives i, 3, 6a*, TVa* oil immersion. N.A. 1.32 ; eyepieces, O, II, IV, V; magnifications 13 — 1176 .. .. .. .. .. .. each £29 10 0 920T Same Stand with Substage (a); triple nosepiece; micrometer eyepiece, No. 1028, objectives 2, 4, 6, ft oil-immersion, N.A. 1.30; eyepieces I, III, IV, V; magnifications 29 — 1260 . . . . . . . . . . . . • • • • each £26 5 0 921' Same Stand with Substage (aj ; triple nosepiece; objectives 3, 6, f.,, oil-immersion, N.A. 1.30 ; eyepieces I, III, IV ; magnifications 51 — 1050 . . . . ... each £23 0 0 922' Same stand with Substage (a) ; triple nosepiece ; objectives 3, 7a*, ft a* oil-immersion, N.A. 1.32 ; eyepieces O, II, IV ; magnifications 41 — 980 .. .. .. each £25 0 0 923' Stand with Substage (a), exclusive of objectives, eyepieces, and nosepiece * 6a, ya and i'aa are fluorite lenses. £14 0 0 JCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 19.5 BAIRD &TATLOCK (LONDON) LTD. 924-927 Stand C. 928-931 Stand D. 932-935 Stand F. 924T 925' 926' 927' 928' 929T 930'1' 931' 932T Large Microscope C (I.eitz), somewhat smaller than A and B, with modified horseshoe toot. The stand is inclinable. It has a centring and revolving stage, rack and pinion coarse adjust- ment, new continuous safety micrometer movement with divided drum (each division = 0.002 mm.), and a graduated draw-tube. It is equipped with a large substage (b) fitted with rack and pinion and iris diaphragm with lateral movement. The condenser is inter- changeable against a cylinder diaphragm. Triple nosepiece ; objectives 2, 4, 6, TV oil- immersion, N.A. 1.30 ; eyepieces I, III, IV, V ; magnifications 29 — 1260 . . each Same Stand with Substage (b) ; triple nosepiece ; objectives 3, 6, ^ oil-immersion, N.A 1.30 ; eyepieces I, III, IV ; magnifications 51 — 1050 . . . . . . each Same Stand with Substage (b) ; triple nosepiece ; objectives 3, 6, 8 ; eyepieces, I, III, IV ; magnifications 51 — 691 . . . . . . . . . . . . each Same Stand with Substage (cs), swing-out condenser and conical iris-diaphragm ; triple nosepiece ; objectives 3, 7, T^ oil-immersion, N.A. 130 ; eyepieces I, III, IV ; magnifi- cations 51 — 1050. . . . . . . . . . . . . . . each Large Microscope D (Leitz), differing from C. in the form of the stage only. The latter is of the fixed square type. The stand is inclinable. The draw-tube is graduated in millimetres. The coarse adjustment is effected by a rack and pinion, the fine adjustment by the new continuous safety micrometer movement reading to 0.002 mm. The stand is fitted with substage (b), like Stand C. Triple nosepiece ; objectives 3, 6, T\ oil-immersion, N.A. 1.30 ; eyepieces I, III, IV ; magnifications 51 — 1050 . . . . • . . each Same Stand, with Substage (cs) ; triple nosepiece ; objectives 3, 6, TV oil-immersion. N.A. 1.30 ; eyepieces I, III, IV ; magnifications 51 — 1050 . . . . . . each Same Stand with Substage (c) ; triple nosepiece ; objectives 3, 6, ^ oil-immersion, N.A. 1.30 ; eyepieces I, III, IV ; magnifications 51 — 1050 . . . . . . each Same Stand, with Cylinder Diaphragm, but without substage condenser. Double nosepiece ; objectives 3, 7 ; eyepieces I, III ; magnifications 51 — 500 . . each Medium Sized Microscope F (Leitz). Stand with joint for inclining the body at 45°, with fixed square stage, horseshoe foot, coarse adjustment by rack and pinion, new continuous safety micrometer movement, draw-tube with millimetre scale, condenser (c) with iris diaphragm to slip into a sleeve attached to the underside of the stage. The condenser and cylinder diaphragm are interchangeable. A ring below the iris diaphragm serves to hold a ground glass or coloured disc. Triple nosepiece ; objectives 3, 6, TV oil-immersion, £21 0 £19 10 £16 10 £18 15 £18 15 £18 0 £17 5 £10 5 0 N.A. 1.30; eyepieces I, III, IV ; magnifications 51 — 1050 933' Same Stand with Condenser ; triple nosepiece ; objectives 3, 6, 8 ; eyepiece magnifications 62 — 691 934' Same Stand, without condenser ; double nosepiece ; objectives 3, 7 magnifications 51 — 500 each II, IV ; each eyepieces I, III ; each 935\Same Stand, without condenser ; objectives 3, 7 ; eyepieces I, III ; magnifications 51 — 500 £14 15 0 £11 10 0 £800 £750 CROSS STREET • HATTCTrST GARDETST, E- C BAIRD &TATLOCK (LONDON) LTD. 936-939 Stand G. 940-942 Stand la. 936T Medium Sized Stand G (Leitz). Stand with joint for inclination at 45°, with fixed square stage, horseshoe foot, coarse adjustment by rack and pinion, new continuous safety micrometer movement, draw-tube with millimetre scale, condenser (c) with per- manently attached iris diaphragm to slip into the sprung sleeve (underneath stage). The condenser and cylinder diaphragm are interchangeable. A ring is attached to the mount of the iris diaphragm for holding a ground glass or coloured glass disc. Triple nosepiece ; objectives 3, 6, ^ oil-immersion, N.A. 1.30 ; eyepieces I, III, IV ; magnifi- cations 51 — 1050 .. .. .. .. .. .. .. each 937' Same Stand with Condenser ; triple nosepiece ; objectives 3, 6, 8 ; eyepieces, II, IV ; magnifications 62 — 691 . . . . . . . . . . each 938' Same Stand without Condenser ; double nosepiece ; objectives 3, 7 ; eyepieces I, III ; magnifications 51 — 500 . . . . . . . . . . . . each 939T Same Stand without Condenser ; objectives 3, 7 ; eyepieces I, III ; magnifications 51— 500 . . . . . . . . . . . . . . . . . . each £14 5 0 £11 0 0 £7 10 0 £6 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK. (LONDON) LTD. 940 941 942' 943' 945' 946' 947' 948T 949T 950' Large Microscope la (LeiU) , with horseshoe foot, or English foot. The stand is inclin- able and fitted with revolving and centring stage, coarse adjustment by rack and pinion, fine adjustment by micrometer screw with scale reading to ^ mm. Draw-tube with millimetre scale. Large substage (b) with rack and pinion and iris diaphragm with oblique movement. The cylinder diaphragm and condenser are readily interchangeable. Triple nosepiece; objectives 2, 4, 6, ^ oil-immersion, N.A. 1.30; eyepieces I, III, IV, V ; magnifications 29 — 1260 . . . . each Same Stand with Substage (b) ; triple nosepiece ; objectives 3, 6, TV oil-immersion, N.A. 1.30 ; eyepieces I, III, IV ; magnifications 51—1050 . . . . . . each Same Stand with substage (b) ; triple nosepiece ; objectives 3, 6, 8 ; eyepieces I, III, IV ; magnifications 51 — 691 . . . . • • • • . . . . each 943-946 Stand Ib. 947-950 Stand III. Large Microscope Ib (Leitz), differing from Stand la., only by the form of the stage. The latter is of the fixed square pattern. The stand is inclinable and has a clamping lever, draw-tube with millimetre scale, coarse adjustment by rack and pinion, fine adjustment by micrometer screw with graduated head reading to TJn mm. The substage is the same as that of Stand la. Triple nosepiece ; objectives 3, 6, TV oil- immersion, N.A. 1.30 ; eyepieces I, III, IV ; magnifications 51 — 1050 . . each Same Stand with Substage (c) ; triple nosepiece ; objectives 3, 6, J^ oil-immersion, N.A. 1.30 ; eyepieces I, III, IV ; magnifications 51 — 1050 . . . . . . each Same Stand with Cylinder Diaphragm instead of the substage ; double nosepiece ; objectives 3, 7 ; eyepieces I, III ; magnifications 51 — 500 . . . ., . . each Same Stand with Cylinder Diaphragm ; objectives 3, 7 ; Eyepieces I, III ; magnifica- tions 51 — 500 . . . . . . . . ..... . . . . each Stand III is now provided with a rack and pinion coarse adjustment instead of the sliding tube. A nosepiece may thus be used on it to advantage. It will be found to be an excellent and inexpensive class microscope. Medium Size Microscope III (Leitz), with iron foot and upright cast in one piece, coarse adjustment by rack and pinion, fine adjustment by micrometer screw. The draw-tube has a millimetre scale. Plane and concave mirror, and wheel-diaphragm. Triple nosepiece ; objectives 3, 6, 8 ; eyepieces I, III ; magnifications 51 — 553 . . each Same Stand ; triple nosepiece ; objectives 3, 5, 7 ; eyepieces I, III ; magnifications 51 — 500 Same Stand, double nosepiece ; objectives 3, 7 ; eyepieces I, III ; magnifications 51—500 Same Stand, objectives 3, 7 ; eyepieces I, III ; magnifications 51—500 .. .. each £20 0 0 £18 10 0 £15 10 0 £17 15 £16 5 £9 5 £8 10 0 £8 5 £7 10 £6 0 £5 0 0 0 0 CROSS STREET • HATTCnST GARDETST, E-C- BAIRD &TMXOCK (LONDON) LTD. 951-955 Stand GH. (New School Microscope.) 951T Medium Sized Microscope GH (Leitz). Stand with joint admitting of the body being tilted to 45°, horseshoe foot and stem cast in one piece, coarse adjustment by rack and pinion, fine adjustment by means of the new micrometer screw with lever trans- mission. The draw-tube is graduated in millimetres. The condenser (c) has an iris dia- phragm permanently attached to it and slips into a sleeve attached to the underside of the stage. The condenser and cylinder diaphragm are interchangeable. A swing-out ring attached to the face of the iris diaphragm fitting serves to hold a ground or coloured glass-disc. Triple nosepiece ; objectives 3, 6, TV oil-immersion, N.A. 1.30; eyepieces I, III, IV ; magnifications 51 — 1050 . . . . . . . . . . each 952T Same stand with condenser ; triple nosepiece ; objectives 3, 6, 8 ; eyepieces II, IV ; magnifications 62 — 691 . . . . . . . . . . . . each 953' Same Stand without condenser ; double nosepiece ; objectives 3, 7 ; eyepieces I, III ; magnifications 51 — 500 . . . . . . . . . . . . each 954T Same Stand without condenser and without nosepiece ; objectives i, 3, 7 ; eyepieces II, IV ; magnifications 19 — 625 . . . . . . . . . . . . each 955T Same Stand without condenser and without nosepiece ; objectives 3, 7 ; eyepieces II, IV ; magnifications 62 — 625 .. .. .. •• •• •• each £13 0 0 £9 15 0 £650 £650 £5 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 199 BAIRD &L TATLOCK (LONDON) LTD. 960-962 Stand Vila. Small Microscope VII. (I.eitz). The stand is hinged and inclines np to 45°. It has a finely cut rack and pinion movement by means of which fairly high powers mav be focussed with ease. The stage measures 10 by 9 cm. The stand is adapted for the same uses as Stand VI. Objective 3, eyepieces O and IV. ; magnifications 40 and 100 each 957T Same Stand. Combination lens, eyepiece IV. ; magnifications 35 and 100 each 958' Same Stand. Simplified double nosepiece ; objectives i*, 3 ; eyepiece IV. ; magnifications 27 and 100 . . . . . . . . . . . . . . . . each 959' Same Stand for counting colonies on culture plates by Prof. Picker's method. Objective 3, eyepieces II. and IV. ; eyepiece cross-line micrometer ; magnifications 62 and 100, each 960T Microscope Vila. (Leitz), similar to Stand VII. but with a detachable stage measuring 9 by 17 cm. objective 3, eyepieces O and IV. ; magnifications 40 and 100 .. each 96 1T Same Stand. 962 Combination lens, eyepiece IV. ; magnifications 35 and 100 Same Stand. Simplified double nosepiece ; objectives i*, 3 ; eyepiece IV. ; magnifications 27 and loo . . . . . . . . . . . . . . . . each £2 10 £2 10 £3 3 £2 15 £2 15 £2 15 £3 8 CROSS STREET • HATTCXN GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. Large Travelling Microscope with Cam and Worm Screw Focussing Mechanism. In Leather-covered Case, nj x 8J x -jj inches. 963-967 Large Travelling Microscope with Cam and Worm- Screw Focussing Mechanism, showing the instru- ment as it appears when set up for use. 963-967 The Large Travelling Microscope with Cam and Worm Screw Focussing Mechanism conforms in its dimensions and general design to Stand D. It is fitted with the new form of fine adjustment with milled heads at the sides and has a substage (c). 963T Large Travelling Microscope with Cam and Worm Screw Focussing Mechanism, substage (c), and a double nosepiece . . each 964' Same Stand with Substage (c s), and triple nosepiece 965' Same Stand with substage (c) and double nosepiece; objectives 3, 7 ; eyepieces II., IV. ; magnifications 62 — 625.. in. oil- each £9 £10 each £12 0 0 966T Same Stand with substage (c s), and triple nosepiece ; objectives 3, 6, immersion, N.A. 1.30 ; eyepieces I., Ill ; magnifications 51 — 840 . . 967' This microscope may be fitted with a Mechanical Stage No. 1025 £18 0 £3 10 iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 201 BAIRD &. TATLOCK. (LOM)ON) LTD. Small Travelling Microscope. In leather case TO] by 6J by 3$ inches. 968-971 968' Small Travelling Microscope (Leitz). This microscope is made ready for use by spreading the foot, inserting the mirror, and setting the stage. It is provided with a micrometer adjustment like Stand V., a coarse adjustment by rack and pinion, and a condenser with iris diaphragm. The box accommodates three objectives, two eyepieces and a brass box for a bottle of cedarwood oil. It is fitted with a lock and handle, and measures lof by 6J by 3-4- inches. The whole apparatus weighs 5 Ibs. 969' The Same Stand with objectives 3, 6, TV inch oil-immersion, N.A. 1.30 ; eyepieces I. and III. ; magnifications 51 — 840 970' Stand without condenser 971T Same Stand with objectives 2, 4, 7 ; eyepieces I. and III. ; magnifications 29 — 500 Petrological Microscope HIM (Leitz's), illustrated on page No. 203. The coarse adjustment is obtained by a rack and pinion mechanism, the fine adjustment by a micrometer screw. The tube has a millimetre scale. At its lower end the tube carries a centring head with a slot and shutter for the introduction of selenite and mica compensators. Above the centring head is a tube analyser which can be drawn in and out. A Bertrand lens mounted in a slide plate is similarly accommodated in a slot in the upper part of the tube. The condenser and polariser are raised and lowered by a worm screw. The change from convergent to parallel light is obtained by a quarler turn of a milled head at the side, which throws out the two upper lenses of the condenser. The polariser is marked at o°, 90°, 180° and 270°, and withdraws easily from its sleeve. The stage is divided into whole degrees and has a vernier, by means of which the amount of the rotation of the stage may be read to ^ degree. The top of the stage is traversed by lines of orientation. 972r Petrological Microscope HIM (Leitz's) Objective changing clutch with 4 adapters Achromatic objectives i*. 3, 6, TV inch oil-immersion, N.A. 1.30 Eyepieces I. and III. with sliding eyelens and cross webs Micrometer eyepiece II., No. 1028.. Stage micrometer, No. 1032 Selenite film, red ist order, and mica film J cm., both mounted Completely equipped microscope £4 0 £11 15 £3 0 £7 0 £10 15 0 £0 16 0 £7 13 0 £0 18 0 £0 10 0 £0 5 0 pn x n £21 5 CROSS STREET • HATTOTST GARDEKT, E- C 53U.=-*5t k^-^il RAIRD &TATLOCK (LONDON) LTD. 972-973 5B 973T Petrological Microscope Stand HIM (I.eitz). Specification on page No. 202 £10 15 0 Objective changing clutch with 3 adapters . . . . . . . . £0 15 0 Achromatic objectives i*, 3, 6 . . . . . . . . . . £2130 Eyepieces I. and III. with sliding eyelens and cross webs . . . . £0180 Micrometer eyepiece II., No. 1028 .. .. .. .. .. £0 10 0 Selenite film, red ist order, and mica film J wave length, both mounted . . £080 Completely equipped microscope £15 19 6 974'. This microscope may also be fitted with a drop-over analyser for stauroscopic determinations extra £1 13 0 975T Also with an eyepiece I. with Bertrand quartered quartz plate . . . . „ £1100 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 203 BAIRD &TXTLOCK (LONDON) LTD. 976 Greenough's Stereoscopic Binocular Microscope (Leitz's). Two microscope tubes are so arranged as to bring the same object into focus in the axis of each tube, the tubes being set at an angle to each other for this purpose. The image is erected by Porro prisms. The Stand is provided with rack and pinion coarse adjustment. 976' Stand, fitted with hand rests 977T Objectives, 48 mm. . . .... per pair A9771 ,, 40 mm. .. ......,, B977T ,, 32 mm. . . ....... c977T „ ' 24 mm 978T Eyepieces o, i, 2, 3, 4 Mahogany Case included with Optical equipment without extra cost. Table of Magnifications of Objectives and Eyepieces for above Microscope. £8 0 £1 15 £2 0 £2 0 £2 0 £0 10 OBJECTIVES. EYEPIECES. Focal Length. Working Distance. O. I. II. III. IV. 48 mm. 65.8 mm. 10 13 16 21 27 diameters. 40 mm. 31 mm. 16 20 24 3° 4° 32 mm. 24.1 mm. 24 3i 36 48 60 24 mm. 22.8 mm. 29 3* 41 55 68 CROSS STREET • HATTOTST GARDE1ST, E'C 204 M^IP BAIRD .ScTATLOCK (LONDON) LTD. 'VW-* 979-981 Leitz's Micro -Metallograph. I !:r micro-metallograph shown in above figure is designed for visual observation as well as lor the photo- .iphic study of metal surfaces. The construction of the apparatus embodies the principle first applied y l.r Chutelier and certain improvements suggested by Dr. \V. Guertler, that is to say the object is placed ipon the stage (T), whilst the objective is underneath. In the act of focussing the stage moves together with the object, whereas the objective and the illuminating system remain stationary. This part of the apparatus is its most important feature.* The apparatus has the advantage that it is available with any magnification, Li-sides being readily adjustable in such a manner as to obviate detrimental reflections or glares. [lie micro-metallograph consists essentially of three parts, all of which are mounted upon an optical bench, viz., a stand with tube and stage, a lamp with iris-diaphragm and illuminating lenses, and a photographic camera. Descriptive Pamphlet on upj-lication. 979' Micro-metallograph with illuminating apparatus on small optical bench with electric arc lamp burning at 4 amps., on stand, diaphragm disc with iris diaphragm and illuminating lenses, focussing and adjusting keys, carrier with dark glass cap for the eyepiece 980 ' Large mechanical stage fitting the fixed stage of the metallograph . . . . extra 981' One Photographic Camera on optical bench, with 280 millimetres extension, ground glass and transparent focussing screen, two single dark slides 13 by 18 centimetres (7 by 5 in.) with 9 by 12 centimetres (4^ by 3$ in.) plate-holders and focussing lens 982' A larger Camera of i metre extension can be supplied with two dark slides, 24 by 24 centi- metres plates, and having carriers for 18 by 13 and 12 by 9 centimetres ; 18 by 18, 13 by 13, and 9 by 9 centimetres plates, or English sizes at an extra cost of 983' Rheostat for a no volt circuit * .. .. .. .. .. .\983' „ for a 220 volt circuit* 984 ' Mirrosummar F/4.5== 42 millimetres focal length A984T ,, F/4-5=35 millimetres focal length 985 ! Objective No. I . . 986 987' 988' 989' 990 991' 992 993' No. 2 . . „ No. 3 „ Xo. 4 .. „ No. 5 Xo. 6 . . ,, Xo. ya Xo. 8 . . I-J2 inch oil-immersion lens, N.A. 1.30 994' 2 millimetres apochromatic objective 995' Eyepiece Xo. 2 . . £25 £4 15 0 5 0 £500 £2 £0 £1 £3 £3 £0 £0 £0 £1 £1 £1 £2 £2 £5 £12 £0 10 0 15 0 4 0 0 0 0 0 15 0 15 0 15 0 5 0 5 0 10 0 0 0 0 0 0 0 10 0 5 0 *\Vhen ordering, please state whether the available current is continuous or alternating, and the voltage. ST. BAIRD &TATLOCK (LONDON) LTD. 996-997 998 R. Pfeiffer's Erect-vision Dissecting Microscope (Leitz's). The stand of this microscope has been so designed as to render the instrument available for travelling pur- poses. Its foot is made to fold up. The stage may he turned into line with the tube and the metal hand-rests folded back upon the stage, to which they are attached by hinges. The stage opening is closed by a glass disc. below which is an iris-diaphragm to regulate the size of the active opening. The stand is fitted with a plane and concave mirror. Focussing is effected by rack and pinion. Two Porro-prisms are mounted within a tube in such manner that by two successive reflections of the image formed by the objective an erect image is obtained in the eyepiece. The latter is of the Ramsden type. The outfit includes objectives i, 2. 3, which possess considerable working distances. The following table gives the magnifications and working distances of these objectives in conjunction with the eyepiece : — Objective .. .. .. .. ..i 2 3 Magnification .. .. .. ..20 42 <>« diam. Working distance . . . . . . . . 46 mm. 20 mm. 7 mm. 996T Folding dissecting microscope, stand only A. Prism tube, with one eyepiece B. Objectives i, 2, 3 . . . . . . . . . . at I5/- each 997T Stand, with complete outfit Large Dissecting Microscope (Leitz's). Stand on heavy horseshoe base, large stage with glass plate, adjustment by rack and pinion. The lens- carrier is movable for examining large plates. Illumination by movable plane mirror and white glass plate. The case contains leather covered metal hand-rests which during use may be attached to the sides of the stage. During dissection with incident light a dark metal plate may be slid below the stage. 998' Stand, without lenses, in case . . 999' The same, with three aplanatic lenses of the Steinheil type magnifying 8, 16, and 20 diam. 1000 'The same with these lenses and Abbe's drawing apparatus 1001T The same stand with prism-tube for erect vision objectives i*, 2, 3, magnifying 20, 42, and 90 diam. . . . . . . . . . . . . . . £7 £5 £5 18 0 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. 1002-1003 1002' Simple Dissecting Microscope (Leitz's), with adjustment by rack and pinion, movable plane mirror and white glass plate, glass stage in metal frame. Metal hand-rests covered with leather and fitting inside the case. Stand without lenses 1003' The same, with two aplanatic Steinheil lenses. Magnifications 10 and 20 diam. . . £200 Steinheil Lens. 1005 Steinheil Lens. 1008 Aplanatic Steinheil Triplets (Leitz's) are remarkable for their large, flat field, excellent definition, and freedom from chromatic aberration. 1004 1005' 1006' 1007' 1008' 1009 1010r Diameter. Visual field. Magnification. 24 mm. 30 mm. 8 diam. £0 10 0 18 „ 20 „ 10 £0 10 o 14 .. 12 „ 12 £0 10 (t ii 8 „ id „ £0 10 0 6 .. 3-5 ,. 20 ,, £0 10 0 5 .. 2 ,, 30 „ £0 10 0 3 .. I „ 4° » £0 10 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIBD dcTATLOCK. (LONDON) LTD. 1011 Neisser's Marking and Counting Apparatus for Bacterial Colonies. The Neisser counting apparatus provides the means of counting the bacterial colonies in cultures, etc., and for marking particular colonies, for which purpose the vertical construction of the apparatus renders it very convenient in use. The Petri dish is held firmly in a vertical frame by means of a spring lever and is thus brought exactly opposite the eye of the observer. Immediately behind the Petri dish a glass screen, divided into squares, is mounted, and is ruled with sub- divisions as a further aid to localisation. A short distance behind the frame containing the dish, a second carrier, fitted with a thin metal screen is mounted, in order to reduce the transmitted light and allow of the more ready observation by lateral illumination. The whole frame carrying the dish is adjustable in both the vertical and horizontal directions by rack and pinion, a focussing magnifier being mounted on a pivoted arm in front of the frame and permitting of the critical examination of all parts of the dish. A rigid bar fixed to the lens holder at any point by a set screw, provides a support for the hand when marking the colonies. . The complete mechanism is carried on a pillar, mounted in a heavy base. A special counting screen is supplied, provided with 15 square apertures arranged in a wedge pattern, and serving to estimate the number of the colonies, at 4 places, in 60 squares. The upper edge of the counting screen is provided with lines which serve as scales for the Petri dish : the numbers on the one side show the diameters of the latter in millimetres, whilst those on the other side indicate the number of times the superficial area of the 60 squares is contained in that of the whole Petri dish. Thus it is necessary only to count the colonies in the 60 squares and to multiply this number by the factor correspond ir.g with the size of the dish in order to ascertain the total number of colonies in the dish. 1011' Neisser Apparatus, with one lens magnifying 8 diameters each £700 10121 Neisser Apparatus, with solid instead of hinged pillar, and with one lens magnifying 8 diameters . . . . each £6 15 0 CROSS STREET • HATTCnsT GARDEN, E-C BAIRD &TATLOCK (LONDON) LTD. 1013-1014 1015-1016 1013' Dissecting Stage with opal plate, movable lens holder, but without leu- . . £050 1014' The Same with lens . . . . . . . . . . . . ..£088 10151 Demonstration Lens Holder. Vulcanite stage with handle. The specimen is held in position by clips : the lens carrier is pivoted in the upright pillar. \Yithout lens £060 1016' Handle with spring ring to clip the lens . . . . . . . . . . ..£030 1017 1017T Revolving Nosepiece for two objectives (double nosepiece) . . 1018T Revolving Nosepiece for three objectives (triple nosepiece) . . 1019' Revolving Nosepiece for four objectives 1020' Objective Clutch with three adapters Nosepieces are adapted to existing stands free of charge. 1018 1021-1022 1021' Double Demonstrating Eyepiece magnifying 4 diameters 1022' Double Demonstrating Eyepiece magnifying 6 diameters Specification on page No. 210 £0 15 0 £100 £150 £0 15 0 £2 15 0 £2 15 0 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BATED & TATLOCK (LONDON) LTD. Double Demonstrating Eyepiece. 'Ibis eyepiece enables two observers to view jointly an object under the microscope. It slips into the draw- tube of the microscope like an ordinary eyepiece. The field of view is common to both eyepieces and contains a pointer which either observer can direct upon any feature to which he wishes to draw attention. The arrangement of the device is shown in the subjoined figure : I. and II. are two prisms in contact and mounted above the diaphragm between the field lens and the eye lens of the eyepiece. The prism I. has an isosceles cross section and its angles are 35°, 35°, and 110° respectively. The prism II is rectangular, and its angles are 35°, 55°, and 90°. The prisms are placed with those faces in contact which subtend the angles of 90° and 110° in such a manner as to leave between them a very thin film of air. This film is inclined at an angle of 30° to the axis of the eyepiece and partially reflects the emerging pencil of rays ; about two-thirds of the rays pass through the prisms, and one third is reflected. The image formed along the axis of the microscope is accordingly brighter than that produced by partial reflection. The centre line of the reflected pencil is inclined at an angle of 70° to the axis of the microscope. III. is the prism, the lower surface of which reflects the pencil upwards at a convenient angle for observation. In order that the two observers may not be in each other's way the branch tube is fitted with a system of lenses which resembles a terrestrial eyepiece. The image as seen in the side tube is reversed with respect to that which appeara in the axial eyepiece ; but this would hardly affect the observer, especially since the oblique attachment of the side eyepiece already introduces unusual conditions of working. As a matter of fact the more expedient course is to adjust and focus the object through the principal eyepiece, as the image seen through it is brighter and easier to focus. The adjustment for one eyepiece furnishes also a clearly defined image in the subsidiary eyepiece, provided the eyes of both observers can accommodate in a similar manner. The objective in conjunction with the filed lens below the double prism of the two eyepieces forms an image in the plane of the diaphragm below the double prism. This image and the pointer, being both in the plane of the diaphragm, are seen simultaneously in the principal and the subsidiary eyepieces. The pointer can be moved backwards and forwards and turns on a pivot so that its extreme end can be set to any point in the field. The Double Demonstrating Eyepiece is made in two powers, one having a magnification of 4 diameters, the other of 6 diameters. In both cases the resulting images are sharp, colourless, and free from distor- tion. The fact that the image seen in the subsidiary eyepiece is fainter than the other is no serious drawback as the eyepieces are solely intended for demonstrating purposes, and the demonstrator's acquaintance with the object will generally enable him to see every detail clearly under these less perfect conditions. When diffuse day- light does not suffice to bring out fine details distinctly in the darker portions of the field it will be necessary to use one of the artificial illuminators which are generally to be found in laboratories, such as electric glow-lamps, arc lamps, Welsbach or acetylene lamps. With high power objectives it is generally advisable to set the draw-tube of the microscope about i cm. shorter than its standard length. The Double Demonstrating Eyepiece is also well adapted for the instantaneous photography of living bacteria and other moving organisms illuminated bv means of a dark-ground condenser. It enables one to watch the object through the side eyepiece, and to defer the exposure until a favourable moment presents itself. 1023 1023' Large Mechanical Stage (Leitz's) for Stands A and B This stage is provided with finely cut racks, which render it available for searching preparations of 100 by 50 millimetres. The vernier for the advance and return motion reads i-io millimetre, that lor the lateral motion 1-20 millimetre. Attachment to the microscope is effected by placing the apparatus upon the microscope stage with the knife edge at the back of the mechanical stage resting in the notch in the column of the stand, and fixing by means of the milled thumb screw. This method ensures a rigid stage. This mechanical stage may be fitted at any time. CROSS STREET • HATTO^ GARDETST, E- C BAIRD &TATLOCK. (LONDON) LTD. Or, E 1024 1024' Leitz's Mechanical Stage, adapted for Stands la and Ib, as well as the new Stands A, B, C, andD The stage is readily attachable to Stands la and I b by means of a sere w (c) and a set-pin. It may be detached by simply unscrewing. In the case of Stands A, B, C, and D the mode of attachment is the same as that adopted in the large mechanical stage, No. 1023. The movements of the stage are at right angles to one another, and are accomplished by carefully constructed nu k and pinion movements. The range of the lateral movement is 50 millimetres, that of the other 30 millimetres. Both movements are read by verniers. The spindle of the lateral movement is fitted with a milled head (A), and another on the left to slip on or off. The movement at right angles to it is effected by a pinion head (B). This stage is available for systematically examining large specimens and as a finder for noted points. Such points may always bu found when once accurately recorded, even after detaching and replacing the stage any number of times, sinrc the construction of the stage ensures its fixation in an unvarying position. If required for use on Stands la or Ib this stage has to be specially adapted to the stand, for which we make- no extra charge. £3 10 0 1025 1026 1025' Mechanical Stage. This stage may be attached to Stands la and Ib by moans of a thumb screw 1026' Mechanical Stage, as figured, is a little smaller than the preceding stages, and has been designed for use with Stands II. and Ila. It is fitted with simple rack and pinion mot only . . . . . . £3 10 0 £300 SnCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICAL BAIRD &1ATLOCK (LONDON) LTD. MICROMETERS. 1027 1027T Screw Micrometer Eyepiece for the accurate measurement of large objects This apparatus is provided with a Huyghenian eyepiece, between the eye and field lenses of which there is a millimetre scale ruled on glass, and above this a movable index whose position is controlled by a micrometer screw terminating externally into a graduated drum. The value of each division on the drum, about 5\ of the micro- meter value of the objective, must be determined for each combination of ocular and objective by means of the stage micrometer. The eye lens of the ocular is movable for accurately focussing the scale. The apparatus slips into the tube of the microscope like any ordinary eyepiece and is fixed in position by a thumbscrew at the side. 1028' Micrometer Eyepiece. The mount unscrews in the centre for the introduction of the micrometer scale. The eye lens is movable for accurately focussing the scale 1029' Glass Micrometer for the Eyepiece, to drop on the diaphragm of the eyepiece. Scale of 5 mm. divided into 100 parts . . 1030'1' Glass Micrometer Eyepiece, 10 mm. divided into 100 parts 1031T Stage Micrometer, i mm. divided into 100 parts ruled on glass 1032T Stage Micrometer, photographed on glass, 2 mm. divided into 200 parts 1033T Eyepiece Cross Line Micrometer, divided into squares for counting scattered objects in the field. Mounted. Interval between the lines 0.5 mm £2 10 0 £0 10 £0 £0 £0 £0 £0 5 1034r Ehrlich's Eyepiece 1034 £1 10 Contains a diaphragm with a square opening, which is adjustable within definite ratios for purposes of counting. This eyepiece is designed to facilitate the estimation of the relative numbers of red and white blood corpuscles in dry stained preparations. Full directions accompany each instrument. 212 BAIRD &. TATLOCK. (LONDON) LTD. 1036-1038 1035' Drawing Eyepiece each £150 Is so arranged as to throw the image vertically downwards behind the microscope when the latter is inclined ut an angle of 45 degrees. The reflected image is sharp and free from distortion when microscope and drawing papers are in their proper position. The intensity of the light may be modified by smoked glasses mounted in two movable metal collars. The position of the drawing surface, and the advantage of drawing while the microscope is in an inclined position will be found most convenient. 1036' Edinger's Drawing and Projection Apparatus (Leitz's) , consisting of a vertical iron standard mounted upon a cast iron sole-plate. A small optical bench is fitted to and may be moved along the standard. The optical bench is provided with the following fittings : — A hand feed arc lamp adapted for a current of five amperes, a two-lens condenser 100 millimetres in diameter, object stage with two microscope condensers, tube stand with coarse and fine adjustment, tube with five hole revolving nosepiece, wooden set square, screen curtains, and focussing rod 1037' Camera, with automatic time and instantaneous shutter, with sleeve, lens- rings for microsummars, dark slide for 30 by 24 centimetre plates with plate-holders, ground-glass and paper focussing screens 1038T Wooden stand £15 10 0 £600 £1 10 0 (Continued en page 214) £23 0 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TmOCK (LONDON) LTD. 1039T If desired the apparatus may be supplied with an arrangement for the projection of lantern slides or sections consisting of a special stage . . . . . . extra 1040' A projection objective, anastigmatic 10411 The Rheostat is charged extra, and the price depends upon the nature of the current to be used. For 100 to no volts, 17/6 ; 200 to 220 volts, 27/6. 1042' Eyepiece micrometer, for placing on the diaphragm of the eyepiece, being 5 millimetres divided in 100 parts 1043T Eyepiece micrometer, 10 millimetres divided in 100 parts . . 1044T Stage micrometer, I millimetre divided in 100 parts on glass 1045T Stage micrometer, photographed scale, 2 millimetres divided in 200 parts £100 £4 10 0 £060 £050 £090 £050 1046 (Analyser). 1046 (Polariser). 1046T Polarising Apparatus for food analysis The analyser forms part of an eyepiece which fits into the tube of the microscope, and is provided with a graduated disc and index. It is fixed in any desired position by means of a thumbscrew. The polariser, when used in connection with Stands A, B, C, D, la and Ib, fitted with either of the illuminators, a or b, is hung in the carrier of the iris-diaphragm. When used on stands provided with the- smaller illuminators, c or d, it has to be specially mounted so as to take the place of the cylinder diaphragm, and, if desired, may be furnished with a condensing lens (53. extra) . 1047T Simple Polarising Apparatus. The analyser is without an eyepiece and has no graduated disc. The polariser is as described above 1048T Selenite and Mica Films. Set of eight .. 1049' Object Marker, fitted with a writing diamond, with the aid of which a circle may be drawn round the object This facilitates the process of finding any particular part of a specimen by surrounding it by a visibly marked circle. To mark a certain portion of an object as seen under the microscope the lens should be replaced by the object marker. £0 10 0 CROSS STREET • HATTCHSr GARDETST, E-C q. 44 BAIRD &TATLOCK (LONDON) LTD. 1050 1052 1050T Demonstration Ocular each £080 Kimiitzky's (see Zeiiscfirift /. wissensch. Mihroskopie, vol. xiii., 1896, p. 145) indicates »,ny particular portion of tlic image to which it is desired to draw particular attention. It consists of a pointer which may be moved by a suitable lever. By this movement and the rotation of the eyepiece in the tube any point in the field may he reached. 1051' Erecting Prism each £0 18 0 This fits over the eyepiece and erects the image produced in the compound microscope, thereby facilitating on the stage of the microscope. REFLECTING CONDENSERS For Dark Ground Illumination and Ultra-microscopic Observations. 1052' Concentric Reflecting Condenser, Type A*, in sliding sleeve with centring collar each 1053T Sleeve for the above (This is necessary in the case of those Stands only which are fitted with a swing out condenser of the old type. \iti-r swinging the condenser out and opening the upper iris-diaphragm to its full extent the dark ground illumina- tor to which the sleeve is firmlv attached is slipped in from below in the place of the condenser.) 1054' Concentric Reflecting Condenser, Type B*, stage plate pattern £200 £0 1 0 each £200 1055T Concentric Reflecting Condenser, Type AA*, large pattern, in sliding sleeve without centring collar . , . . . . . . . . . . . . each £200 1056T Funnel Stop .. .. .. .. .. .. .. .. £010 10571 Ultra Condenser .. .. .. .. .. .. .. „ £6 10 0 1058' Wood Base having mounted upon it a Lilliput arc lamp with condensing lens and adjustable microscope fitting . . . . . . . . . . each £2 15 0 1059T Lilliput Arc Lamp on stand and with condensing lens . . . . . . ,, £200 1060r no-volt Resistance for use with the Lilliput lamp .. .. .. .. „ £0 17 6 106 11 220- volt , „ „ ,. ,. .. .. .. .. „ £176 1062T Nernst Lamp on Stand .. .. .. .. .. „ £0 17 0 1063' Condensing Lens, 100 mm. diameter, on stand . . . . . . . . ,, £100 * I f desired, these condensers may be made of quartz, the prices quoted being in that case subject to an increase of £2 10 0. BAIRD &TATLOCKL (LOM)ON) LTD. 1064 1064'' Achromatic Objectives for Leitz's Microscopes. 1 H'signation Focal I.ength Numerical Micrometer values of Fo Aperture measured with Price Objectives (N.A.) F.vepiece II mm inch i* 42 ^ 0.08 0.059 mm. = 59 n *£0 8 0 i 40 Ii O.II 0.051 mm. = 51 w £0 15 0 i a 33—24 Ii- 1 0.05 — OO.y 0.080 — 0.054 mm- £150 = 80—54 " With correc-ion collar, 2 24 I O.ig 0.028 mm. = 28 M £0 15 0 Dry Lenses 3 16.2 § 0.30 0.016 mm. = 16 n £0 15 0 3a 13.0 1 0.40 0.012 mm. = 12 I* £100 4 10. 0 f 0.47 0.0087 mrn- = 8-7 * £150 5 5-4 1 5 0.68 0.0050 mm. =5 *. £150 6 4.0 i 0.82 0.0035 mm. = 5-5 * £1 10 0 7 3-0 I 8 0.85 0.0027 mm. = 2.7 * £1 10 0 Water-Immersion 10 2.1 Tl_ i. 20 0.0017 mm. = 1.7 P. £3 10 0 Oil-Immersion Lens -fa 1.8 TV 1.30 0.0016 mm. = 1.6 * £500 Specially adapted for meat inspection : 1065' Combination Lens, F(J. = 40.0 and 16.2 mm. ; initial magnification, 3.5 and 10 ; magnification in conjunction with eyepiece IV., 35 and 100 .. .. .. each *) The formula of Objective i* is that of a single doublet. It suffices for many purposes, though its light- transmitting power is slightly less than that of Objective No. i. 1066' Fluorite Objectives, for Leitz's Microscopes. £1 0 Designation Focal Length Numerical Micrometer Values of Fo Aperture measured with Price. Objectives. (N.A.). Eyepiece II mm. inch 1 6a 4.2 * 0.82 0.0039 mm- — 3-9 <* £200 7a 3-2 £ 0.85 0.0029 mm- — 2-9 ** £200 Dry Series . . •( 70 3-0 £ o-95 0.0025 mm- = 2-5 " £350* 1 8 2.6 A 0.87 0.0023 mm- = 2-3 * £2 0 0 f ' 9 2.2 A 0.87 0.0018 mm. = 1.8 * £3 10 Of Oil-Immersion J Tlaa 1.8 A 1.32 0.0017 mm. = 1.7 M £6100 Lenses . . I yj 1.6 A 1.32 0.0014 mm- = 1.4 M £7 10 0 * Objective yb is a double fluorite lens. t Objectives 8 and 9 may be provided with a correction collar at extra cost of 15s. CROSS STREET • HATTCXNT GARDEN, E- C 216 BAIRD &TATLOCK (LOM)ON) LTD. 1067' Huyghenian Eyepieces for Leitz's Microscopes each £050 Designation 0 I. II. in. IV. V. 1 -oral Length : Fe m/m 62.5 50.0 4 ^ ^5 31.25 25.0 20.85 Eyepiece Magnification ^~ 4 5 6 8 10 12 1068' Apochromatic Objectives for Leitz's Microscopes. Designation of Objective Focal Length Fo mm. Numerical (N.A.) Micrometer Values measured with Comp. Eyepiece 4 Price. Dry Series 116 mm. 8 mm. 4 mm. 3 mm. 16 8 4 3 0.30 0.65 0-95 0-95 0.0146 mm. , 0.0071 mm. 0.0035 mm- 0.0026 mm. £300 £400 f£6 0 0 t£6 10 0 Oil Immersion \ 2 mm. " [ 2 mm. 2 2 1.32 1.40 0.0018 mm. 0.0018 mm. £12 10 0 *£16 5 0 * Although, considering its high aperture, this objective is very substantially mounted, yet it is advisable to exercise the greatest care in its use so as to avoid the risk of forcing in the front lens. Should this nevertheless occur we are prepared to remount the lens free of charge, provided it is otherwise undamaged. f With correction collar. 1069' Compensating Eyepieces for Apochromatic Objectives No. 1068. Designation. 2 4 6 8 12 18 Focal Length Fe m/m. Eyepiece Magnification^-0 Price 90 2.8 £0 16 0 45 5-6 £0 16 0 3» 8.3 £0 16 0 22.5 ii. i £150 15 16.7 £150 10 25.0 £100 Al069T Compensating Eyepiece No. 4 or 6 with Micrometer 1070 each £1 1 0 1070' Microsummars with Iris Diaphragm, F/4.5. Available for use on the microscope. Focal Length Price 42 mm. = ig in. £300 35 mm. = ig in. £300 24 mm. = i in. £300 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD & 1ATLOCK (LONDON) LTD. MAGNIFYING POWERS of Leitz's Achromatic, Fluorite, and Apochromatic Objectives in combination with the Huyghenian Eyepieces. Tube-length : 170 mm. Image Distance : 250 mm. Initial Magnifi- Eyepieces. Objectives. cation. Eyepiece 250 a o I. II. III. IV. V. Magnification Fe Fo. 4 5 6 8 10 12 f T* 2.7 ii 13-5 16 22 27 32 i 3-2 13 16 19 26 32 38 la 2.0—3.1 8-12 10-16 13-19 16-25 20-31 26-38 Low Power Dry 2 5-8 23 29 35 46 58 7° Achromatic Lenses. 3 10.3 41 51 62 82 103 123 Objectives. 3a 14.1 56 70 84 113 141 169 4 18.2 73 91 109 146 182 218 _ 5 33-3 133 167 200 267 333 400 J ba 44 176 220 264 352 440 528 ] Objectives 6, 7, 6 48 192 240 288 384 480 576 10, and ,1.. are 7a 58-1 232 290 348 465 58i 697 of the achromatic High Power Dry 7 62.5 250 312 375 500 625 75» type. Lenses. 7b 66.0 270 33» 410 54» 660 820 8 69.1 276 346 415 553 691 830 9 85.2 341 426 5" 682 852 1022 . Water Immersion Lens 90.6 362 453 543 724 906 1087 Objectives 6a, 7a, 8, 9- Aa, ,',„ Oil Immersion f ^a Lenses 98 105 392 420 490 525 588 630 784 840 980 1050 1176 1200 and Objective 7b is a double fluorite 1 tV 114 450 57° 700 900 1140 1400 lens. f i6mm. 11.5 45 57 70 90 "5 I4O Dry Series. -J 8mm' | 4 mm. I 3mm- 23.0 46.0 66.0 90 1 80 270 "5 230 330 140 280 410 180 360 540 230 460 660 280 560 820 Apochromatic Objectives. Oil Immersion 2 mm. 92.0 360 460 560 720 920 II2O J The meaning of the term " Initial Magnification " of an objective and " eyepiece magnification " is fully explained in our booklet entitled " The Microscope and How to use it." 14 -CROSS STREET • HATTCTNT GARDETST, E'C BAIRD &TATLOCK (LONDON) LTD. Micro-photographic Apparatus as describeU, showing horizontal position. 1071 1071 1075 1071T Leitz's Photo-Micrographic Apparatus, with optical bench, illuminating lens, two focussing screens, two dark slides for 24 by 24 cm. plates, having plate carriers for any size plates, English or Continental, focussing lens and connecting sleeves, incandescent gas lamp, focussing rod, vertical stage with stop rings 1072' Leitz's Photo-Micrographic Apparatus, as above, with one metre camera extension £12 10 0 £15 0 0 1073 With Nernst Lamp instead of gas lamp 1074' With Arc Lamp of four amperes instead of gas lamp * extra £0 10 0 1075' Leitz's Photo-Micrographic Apparatus, with two focussing screens, two dark slides for 18 by 13 cm. plates, with plate carrier for 12 by 9 cm. plates, with focussing lens and connecting sleeve. Incandescent gas lamp with reflector and illuminating lens, on stand The desired size of the field is obtained by altering the camera extension. The camera neck is provided with a screw so as to hold microsummars with their adapters, which renders the apparatus available for photography with incident light. *H required with arc lamp please give voltage of supply and if continuous or alternating. £0 15 0 £6 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 1077 Leitz's Universal Projection Apparatus (Epidiascope), designed in accordance with the suggestions of Professor Kaiserling. For prices sec next page. This apparatus is available for projection on the screen under a variety of conditions, viz., by transmitted light, for lantern work, by incident light, for episcopic projection, and for direcl microscopic projection. Its versatile character renders it an invaluable means of illustrating lectures requiring, for their better under- standing, clear and plentiful ocular demonstrations without loss of time. The apparatus has been so designed as to enable the lecturer to pass from one mode of projection to another with as little interruption as possible. As will be seen from the illustration, the apparatus consists of an iron framing, the component parts of which are joined by steel tubes. A screening curtain, which is not shown in the figure for the sake of clearness, surrounds the entire apparatus so as to prevent the escape of stray light, and thus to ensure darkness in the lecture room. The design of the entire apparatus secures lightness combined with the utmost rigidity. The lamp, which regulates itself automatically, is adapted for a continuous current, and is placed behind the optical bench and independent of the latter. A distinctive feature of this lamp is the position of the carbons, which are placed at right angles to each other ; the positive carbon being horizontal and coincident with the optic axis. This is an innovation of considerable importance, since thereby the crater of the positive carbon becomes exposed so as to send forth the whole of the available light. With a current of 30 amps., this lamp produces an intensity of 10.500 c.p., whereas with oblique carbons this same lamp yields 7,000 c.p. only. This implies au increase of 50 per cent, in the intensity of the illumination. Full descriptive pamphlet on application CROSS STREET • HATTOTST GARDETST, E-C- cr ^K?3 BAIRD &TAfLOCK (LONDON) LTD." cr PRICES OF LEITZ'S UNIVERSAL PROJECTION APPARATUS (The Epidioscope). (See page No. 220 for illustration). 1077' No. i. For episcopic and diascopie projection : Automatic projection lamp for a 30 ampere current, casing with arrangement for centring the lamp, frame with hinged optical bench, large rising and falling episcopic stage, externally silvered mirror, cooling chamber on stand, triple adjustable condenser of 210 millimetres diameter, radial arm for the projection lens of 400 millimetres focus, rods with curtains, universal rapid changer with clamp for attachment to the cooling chamber, and lens holder for the lantern slide projection lens £50 0 0 10781 Arrangement for the projection of horizontally placed objects, consisting of a gear for raising and lowering the lamp with condensing lenses, mirror, circular opening in the large stage with condensing lens . . . . £5 // desired the apparatus may be supplied without this arrangement. » 1079' No. 2. For micro-projection : Small optical bench with large movable stage, revolving condenser changer, iris-diaphragm and lens, tube stand, with rack and pinion movement and micrometer screw, triple nosepiece, large tube with iris-diaphragm, triple, revolving eyepiece changer, with three projection eye- pieces. (Tin's arrangement renders a separate lens carrier for the projection of lantern slides unnecessary, since the lens may be attached to the tube 0 0 standl £12 10 0 1080' Uncemented j-lens projection objective F/4 of 400 millimetres focus, corrected spherically and astigmatically . . . . . . . . . . . . £20 0 0 1081 ' Aplanatic Projection Lens of 200 millimetres focus, for lantern slides 1077-1081 Complete outfit as described above £300 1082' Apparatus for the projection of spectra, consisting of a small optical bench with slit, lens, and fluid prism 1083' Rheostat for a continuous current of no volts (The price of the rheostat varies according to the voltage.) 1084' Packing for complete outfit 1085' Resilvering of the reversing mirror G 1086' Cored Carbons for the projection lamp £90 10 0 £12 10 0 £480 £200 £060 per pair £004 We guarantee the proper working of the lamp only when these carefully selected carbons are used. The- prices of objectives and microsummars will be found on pages No. 216-217. 1087T Leitz's Small Epidioscope for the projection of opaque objects and lantern slides, complete £50 0 0 1088r Microscope Attachment for ditto Leitz's Catalogue of Projection and Projection-Drawing Apparatus, giving a detailed description of above, as well as other cheaper models, sent post free. £900 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIBD &TATLOCK (LOM)ON) LTD. MICROSCOPES, MICRO-PHOTOGRAPHIC APPARATUS, PROJECTION APPARATUS, AND ACCESSORIES. Manufactured by CARL ZEISS, Jena. All Apparatus made by C. Zeiss are supplied at his Catalogue prices. 1089' Microscope, Zeiss, Stand Ib, for Bacteriological, Histological, Botanical, and Zoo- logical Research Work. Coarse adjustment by rack and pinion. Fine adjustment by Berger's micrometer movement, with large mechanical stage, and complete Abbe substage condenser, N.A. 1.40, in polished mahogany case A. Apochromatic objective, 16 millimetres, N.A. 0.30 B. „ „ 8 „ N.A. 0.65 . . C. „ ,, 4 „ N.A. 0.95 . . D. ,, ,, 2 „ for oil-immersion, N.A. 1.30 .. , .. E. Compensating eyepieces, Nos. 2, 4, 8, and 12 F. Micrometer eyepiece, No. 6 G. One tube and four objective slides H. Mahogany box for ditto I. Abbe drawing apparatus . . J. Stage micrometer, i millimetre in 100 divisions K. Polarised light apparatus If fitted with swing-out condenser £i 55. extra £20 O O 4 O O 5 O O 7 O O ID 0 O 5 0 O i II O 2 O O 0 15 0 3 0 O 0 10 0 2 18 O £66 14 0 14 -CROSS STRET • HATTOTST GARDEN, E-C BAIRD &.TATLOCK (LONDON) LTD. 1090' Microscope, Zeiss, Stand Ib (Fig. 1089) for Bacteriological, Histological, Botanical, and Zoological Work, &c. Coarse adjustment by rack and pinion. Fine adjustment hy Berger's micrometer movement, revolving vulcanite stage with centring screws and Messrs. Carl Zelss have Immersion objective, substituted : — A. discontinued +, in. N.A. (he manufacture of the oil 1.30, at £6 5s., and have Oil immersion lens, Tl.r in. N.A. 1.30 (Lenses made of Fluorite) .. £700 B. Oil immersion lens, ^ in. N.A. 1.25 £500 The price of outfits described on pages 222 to 228 must be amended according to the lenses selected. BAIRD & TATLOCK (LONDON) LTD. in extra charge of £16 5 0 I IO o I 10 o 2 IO 0 6 5 o o 18 C) o 18 0 2 0 0 0 15 0 3 o o O IO o 2 18 o £38 19 ;e of £3 15 0 1092 1095 1092T Microscope, Zeiss, Stand No. IIIc., for Bacteriological Work, Medical Practi- tioners and Veterinary Surgeons, etc. Coarse adjustment by rack and pinion. Fine adjustment by Berger's micrometer movement with fixed stage and complete Abb6 substage, in polished mahogany case . . . . . . . . £12 10 o A. Achromatic Objective A .. .. .. .. .. 100 B. „ DD . . . . . . . . 2 10 o C. TX5 in. oil-immersion lens, N.A. 1.30 . .. .. .. 650 D. Triple nosepiece .. .. .. .. .. .. 100 E. Eyepieces Nos. 2 and 4 . . . . . . . . o 12 o £23 17 0 1093T Large mechanical stage for above . . extra £5 10 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 223 BAIRD &. TATLOCK (LONDON) LTD. 1094 1095' Microscope, Zeiss, Stand No. Hid. (Fig. 1092), for Botanical and Zoological Investiga- tions. Coarse adjustment by rack and pinion. Fine adjustment by Berger's micrometer movement. Revolving vulcanite stage with centring appliance. Condenser, N.A. 1.40, in polished mahogany case .. .. .. .. .. £14100 A. Achromatic objective a2 . . . . . . . . 0120 B. „ A , . . . . . . . . . 100 C. „ ,. C . . . . . . . . . . i 10 o D. „ „ E .. .. .. .. 300 E. y1!; inch oil-immersion lens, N.A. 1.30 . . . . . . 650 F. Plankton objective (water-immersion) . . . . . . i o o G. Eyepieces Nos. 2 and 4 .. .. .. .. .. o 12 o H. Eyepiece No. 3 with micrometer .. .. .. .. 0180 I. Glass cell for Plankton searcher . . . . . . . . 036 ]. Triple nosepiece .. .. .. .. .. .. 100 K. Abbe drawing apparatus . . . . . . . . 300 L. Stage micrometer, i millimetre into ,,',,, .. .. .. o 10 o Microscope, Zeiss, Stand IVb., suitable for Bacteriological Work, Medical Practitioners, etc. Coarse adjustment by rack and pinion. Fine adjustment with ordinary form micrometer movement with divided head. Condenser, N.A. 1.20, with iris-diaphragm, in mahogany case . . . . . . . . £10 10 o A. Achromatic objective A.. .. .. .. .. 100 B. „ D .. .. .. .. i 15 o C. Jj inch oil-immersion lens.. N.A. 1.30 . . . . 6 =5 o D. Eyepieces Nos. 2 and 4 . . . . . . . . 0120 E. Triple nosepiece .. .. .. .. .. .. 100 1096T Large mechanical stage for above .. 1097' Microscope, Zeiss No.IVc. (Fig. 1095), for Botanical and Zoological Investigations. Coarse adjustment by rack and pinion. Fine adjustment by ordinary microrr.i'ter move- ment, with complete Abbe substage condenser, N.A. 1.20 A. Achromatic objectives a2 . . B. „ „ A .. C. C .. D. „ F. E. TV inch oil-immereion lens, N.A. 1.30 F. Plankton objective (water-immersion1! G. Eyepieces. Nos. 2 and 4 . . H. Eyepiece, No. 3 with micrometer I. Glass cell for Plankton searcher J. Triple nosepiece . . K. Abbe drawing apparatus . . L. Stage micrometer 5 12 O IO O 5. o 12 18 3 o o IO 1098' Microscope, Zeiss, IVf. (Fig. 1095), suitable for Chemical Laboratories, Paper Making Factories, Breweries, and Dairies, etc. Coarse adjustment by rack and pinion. Fine adjustment by micrometer screw, with divided head. Revolving stage with graduated edge, centring arrangement on the tube, complete with Abbe substage condenser, N.A. 1. 20. Apparatus for polarised light, with selenite film for red of the I. order, in polished mahogany case . . . . . . . . . . . . £14 15 o A. Achromatic objective a2 . . . . . . . . . . 0120 B. „ A . . . . . . . . . . 100 C. ,, D . . . . . . . . i 15 o D Jj inch oil-immersion lens, N.A. 1.30 .. .. .. 650 E. Eyepieces, Nos. 2 and 4.. .. .. .. .. 0120 F. Micrometer eyepiece, No. 3 . . . . . . . . 0180 G. Triple nosepiece .. .. .. .. .. .. 100 H. Stage micrometer . . . . . . . . . . o 10 o I. Thoma's counting chamber . . . . . . . . o 14 o £34 0 0 £21 2 0 extra £5 10 0 — £30 15 6 r.28 1 0 CROSS STREET • HATTCTNT GARDEN, E'C 224 BAIRD &TXTLOCKL (LONDON) LTD. Messrs. Carl Zeiss have discontinued the manufacture of the oil immersion objective, A in. N.A. 1.30. at £6 5s., and have substituted : — A. Oil Immersion lens, T\ in. N.A. 1.30 (Lenses made of Fluorite) . . £700 B. Oil immersion lens, jV in. N.A. 1.25 £500 The price of outfits described on pages 222 to 228 must be amended according to the lenses selected. BAIRD & TATLOCK (LONDON) LTD. 1099 1099* Microscope, Zeiss, Stand No. Vd., suitable for Chemical Laboratories, Paper Making Factories, Breweries, and Dairies, etc. Coarse adjustment by rack and pinion. Fine adjustment by micrometer screw. Revolving stage. Graduated edge. Centring arrangement on the tube with polariser, analyser, and selenite films for red £800 o i i 6 o of the I. Order A. Achromatic objective a2 . . „ A .. „ D .. yVm- oil-immersion lens, N.A. 1.30 Eyepieces Nos. 2 and 4 B. C. D. E. F. G. H. I. Micrometer eyepiece No. 3 Triple nosepiece Stage micrometer Thoma's counting chamber 12 o 15 5 12 18 o 10 14 £21 6 0 1100' Microscope, Zeiss, Stand V., with fixed round stage, form A, without condenser, but with three stops of different apertures . . . . . . . . . . . . £4100 1101T Form B, with condenser, N.A. i. .. £5 10 0 1102T Form C, with condenser, N.A. 1.20 .. .. .. .. 1103T Accessories suitable for either of above stands, for students' use : — A. Achromatic objective aa . . . . . . . . B. „ „ A | in. . . . . . . . . C. „ „ D-J in. .. .. .. .. D. ^ in. oil-immersion, N.A. 1.30 . . . . . . . . E. Eyepieces 2 and 4 . . . . . . . . . . F. Double nosepiece . . . . . . . . . . G. Or, triple nosepiece . . . . . . . . . . (For other Objectives and Eyepieces see pages 227-229.) £5 16 0 £0120 £100 £1 15 0 £650 £0 12 0 £0150 £100 .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &IATLOCK: (LONDON) LTD, 1104 1105 1104' Microscope, Zeiss, Stand Hlme, specially designed for Mineralogical and Crystallo- graphic Investigations. Coarse adjustment by rack and pinion. Fine adjustment by Berger's new micrometer movement. Complete Abbe illuminating apparatus, and swing-out condenser, N.A. 1.40. Draw tube provided with rack and pinion, and with • Amici Bertrand lens. Polariser and analyser with graduated circle above the ocular. A second analyser is mounted on slide immediately above the objective with selenite plate red of the I. order. Mica plate £? and Biot-Klein quartz- plate. Large mechanical stage graduated on the circumference and with line index. Price in polished mahogany ... £30 o "o Achromatic objective a2 . . . . . . . . . . o 12 o „ ,, A . . . . . . . . i o o „ DD . . . . . . . . . . 2 TO o F .. .. .. .. .. i is o j-m. oil-immersion lens, N.A. 1.30. . .. .. .. 650 Eyepieces with cross lines, Nos. i, 2, and 4 .. .. .. i 10 o Eyepiece No. 3. with micrometer . . . . . . o 18 o One tube and five objective slides . . . . . . . . 2 JS <, Mahogany box for ditto . . . . . . . . . . o 15 o Abbe drawing apparatus, large form . . . . 300 Stage micrometer i mm. divided in TJn . . . . . . o 10 o Iris-diaphragm with ocular for examining and identifying the axial images of crystals . . . . . . , . . . . 1.50 case A. B. C. D. E. F. G. H. I. J. K. L. T 1105T Microscope, Zeiss, Stand IVf., for Mineralogical and Crystallographic Courses. Coarse adjustment by rack and pinion. Fine adjustment by ordinary micrometer movement with divided head, and revolving stage having a graduated edge. Objective centring arrangement on the tube. Complete Abbe substage condenser, N.A. 1.20, polariser, analyser, and selenite film, red of the I. order A. Achromatic objective A . . B. „ „ D C. Eyepieces with cross lines, Nos. 2 and 4 N.A £14 15 i o i 15 I O £54 8 £18 10 CROSS STREET • HATTOlsr GARDEN, E- 226 sT Off, BAIRD &TATLOCK (LONDON) LTD. 1106 Microscope, Zeiss' Stand Vd., inclinable. Coarse adjustment by rack and pinion, l-'im- adjustment by means of Berger's micrometer movement, with revolving stage provided with graduations at the edge. Objective centring apparatus on the tube. Polariscr, analyser, and selenite film, red of the I. order . . . . . . £8 o 0 A. Achromatic objective A.. .. .. .. .. 100 B. D .. .. .. I 15 o C. Eyepieces with cross lines, Nos. 2 and 4 . . . . . . i o o 1107' Zeiss' Apochromatic Objectives. £11 15 0 ' Combined with Compens. Ocular 4, Tube-length 160 mm. (about 6J in.) Free Diameter of Prices. Messrs. Carl Zeiss have discontinued the manufacture of the oil Working visible area immersion objective, fa In. N.A. 1.30. at £6 5s., and have Distance. of object. substituted : — A. Oil immersion lens, A- in. N.A. 1.30 mm. t mm. (Lenses made of Fluorite) . £7 0 0 5 2 £400 B. Oil immersion lens, ^ i a. N.A. 1.25 £5 0 0 I.O I £500 The price of outfits described on pages 222 to 228 must be amended 0.2 0-45 £700 according to the lenses selected. 0.15 0-35 £800 HAIKU & TATLOCK (LONDON) LTD. 0.18 0.25 £12 10 0 0.2O 0-35 £15 0 0 0.16 0-35 £20 0 0 Immersion 2 2 1.30 1.40 125 0.16 125 0.12 0.25 0.25 £15 0 0 £20 0 0 i-5 1.30 167 0.09 0.2O £17 10 0 1108' Zeiss' Achromatic Objectives. Combined with Huyghen. Ocular 2 ; Tube length Designa- tion. Equivalent focal length. Numerical Aperture. i6omm. (about 6J in.). Pric without Correction- e. with Collar. Free Work- ing Distance. Diameter of visible area of object. mm. mm. mm. f a0 45 — 32 14 £0 12 0 a, 39 — . 20 II £0 12 0 a2 37 — 3« 8 £0 12 0 as 28 — 33 4-5 £0 12 0 a* 43-29 _.. 13-53 10-25 £200 aa 26 O.iy 14 4 £170 A 15 0.2O 9 2 £100 AA 17 O.^O 7-5 2-5 £1 10 0 B 12 0-35 3 i-5 £1 10 0 Dry Series - C 7 O.40 1.8 0.9 £1 10 0 D 4.2 0.65 0.6 0-5 £1 15 0 (£2 10 0 DDf) 4-3 0.85 0.4 0-5 J £3 10 0 |£3 0 0 Ef) 2.8 0.90 0.25 035 J £400 |£3 15 0 I Ft) 1.8 O.gO 0.17 0.23 1 £4 15 0 BAIRD &.TXTLOCK (LONDON) LTD. Zeiss' Achromatic Objectives (continued). 1 PI 25 O.II 36 4 £100 Water Immersion . . -j D* 4-4 0-75 i-5 0-55 £3 15 0 ,£5 10 0 1 \ J 1.8 1.18 0.2 0.23 J ( £6 10 0 Homog. Immersion rV in- 1.8 1.30 0.15 2.05 £650 f These Objectives contain Fluorite Lenses. All these objectives are also supplied adjusted for the English 10-inch body (tube-length 250 mm. (about io-in.)). 1109' Zeiss' Huyghenian Oculars for use with achromatic objectives, No. noS. Ocular No. i 2 2* 3 4 5 Equivalent focus in mm. 5» 40. 40 30 25 20 Ocular magnification 3 4 4 5-5 7 9 Price 6/- 6/r 30/- 6/- «/- 6/- Table of Magnifications of the Achromatic Objectives with Huyghenian Oculars (Nos. 1108 and 1109), calculated for a tube length of 160 millimetres (about 6-| in.) and an image distance of 250 millimetres (about 10 in.). Objectives. HUYGHENIAN OCULARS. I 2 and 2* 3 4 5 a. 4 6 10 12 20 a 7 IO 16 20 30 El, ii 15 23 28 41 a., 20 26 38 47 68 a* 3-8 5-i2 8-18 10-22 16-33 aa 24 31 46 56 81 A 44 56 78 97 144 AA 42 54 74 9i 134 B 63 80 "5 140 200 C IOO 125 1 80 220 315 D 175 220 320 39« 55» DD 175 220 320 39° 550 E 270 34» 495 600 860 F 415 520 760 930 1300 PI 25 33 48 58 84 D* 175 220 320 390 55« J 415 52O 760 930 1300 iV m. 420 530 770 940 1320 In employing nosepiece 01 sliding objective-changer, the length of the nosepiece, amounting to 15 millimetres, and of the sliding objective-changer, 22 millimetres, must be taken into account, CROSS STREET • HATTCHSr GARDEN, E-C 228 BAIRD &TATLOCK (LONDON) LTD. 1110T Zeiss' Compensating Oculars for use with Apochromatic Objectives, No. 1107. Searcher Ocular. Working Oculars. Distinctive No. 2 4 4* 6 8 12 18 Equivalent focal length in mm. . . . . 90 45 45 30 22.5 15 10 30/- 30/- 25/- i the Compensating Messrs. Carl Zeiss have discontinued the manufacture of the oil immersion objective, j"i In. N.A. 1.30, at £6 5s., and have : distance of 250 milli- substituted : — A. Oil immersion lens, T1., in. N .A. 1.30 (Lenses made of Fluorite) .. £700 * ;ulars. B. Oil immersion lens, /.j in. N.A. 1.25 £500 The price of outfits described on pages 222 to 228 must be amended according to the lenses selected. BAIRD & TATLOCK (LONDON) LTD. 12 18 187 281 375 562 4.0 125 250 375 500 750 1125 3.0 167 333 500 667 IOOO 1500 2.5 20O 400 600 800 1200 1800 2.0 25O 500 75» IOOO 1500 2250 i-5 333 667 IOOO 1334 2OOO 3000 III employing nosepiece or sliding objective-changer, the length of the nosepiece, amounting to 15 millimetres, and of the sliding objective-changer, 22 millimetres, must be taken into account. H 1111 1111T Abbe Drawing Apparatus, large form, in case 1112' Abbe Drawing Apparatus, small form, in case £300 £1 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD ^XmOCK (LONDON) LTD. 1113r Ocular Micrometer, in case .. ..£050 1114' Ocular Cross-line Micrometer, in case .. ..£050 1115' Stage Micrometer, i millimetre in 100 parts, in case .. £0 10 0 1116T Stage Micrometer, i centimetre in millimetres, last millimetre in .1 millimetre, in case . . . . ; . . . . . . . . . . . ..£060 Micrometer Oculars for Achromatic Objectives, No. 1108. 1117' Huyghenian Ocular 2 or 3, with micrometer .. .. .. .. .. £0 18 0 1118' Huyghenian Ocular 2 or 3, with drum and screw for moving the micrometer laterally, called the drum ocular with micrometer, in case . . . . . . . . . . £200 Micrometer Oculars for Apochromatic Objectives, No. 1107. 1119' Compensating Ocular 6, with micrometer .. .. .. .. £1 11 0 1120' Compensating Ocular 6, with drum and screw for moving the micrometer laterally, drum ocular with micrometer, in case . . . . . . . . . . . . £2130 1121T Dial Cover Glass Gauge, measuring thicknesses up to 8 millimetres to T£JV A ifS& -* ^ ^ *-l7«U(l |fj 14 • CROSS STREET • HATTO>J GARDETST, E- C- [flj *• Cgfc-'V^^^'- — 5£==^S^t-:^SiA1iP^£*^&£:J— ^) ^as^jS^^38>tJ 234 BAIRD &TATLOCK (LONDON) LTD. Q. Compensating eyepieces, 6 and 12 R. Projection eyepieces, 2 and 4, at £2 . . S. Huyghenian eyepiece, 4 T Tube slide U. 4 objective slides V. Case for objective slides and objectives W. Large photo-micrographic camera X. Focussing lens X 6 Y. Focussing gear and rod 7. Reversing prism Brought forward £62 ,X 6 2 10 4 o 06 0 8 1 12 0 15 IS 10 1 6 at 8s. each 2 II I O - £92 6 6 If instead of achromatic objectives, apochiomatic objectives are required, we recommend — MM. Apochromatic objective, 16 mm. .. .. £400 NN. ,, ,. 8mm. .. .. .. 500 <><>. ,, ,, 4mm. .. 700 PP. „ 2 mm. X. A. 1.30 .. .. :. 15 o o £31 0 0 < v \ i / ,-* n - u Path of rays in paraboloidal condenser 1143-1146 1143 1143' Paraboloid Condenser for dark ground illumination for observing living bacteria .. £200 1144' Cardioid Condenser for examination of colloids .. .. .. .. ..£200 1145' Inverted Gas Lamp with metal chimney .. .. .. .. .. ..£160 1146' Glass Flask on stand .. .. .. .. .. .. .. ..£070 11471 Micro-Nernst Lamp, with condensing lens, for alternating or continuing current. (State voltage and resistance.) . . . . . . . . . . £200 1148' Projection Nernst Lamp with aplanatic condenser, micrometer movement for condenser and filament on saddlestand . . . . . . . . . . ..£550 1149' Light Filter Trough for above and holder .. .. .. .. £0 10 0 Prices /or resistance, either no or 220 volt, on application. 1150' Mercury Lamp," Hageh's Micro-lamp," for monochromatic light. Complete, including resistance, for no volt. 1151T Mercury Lamp, " Hageh's Micro-lamp," for monochromatic light. Complete, including resistance, for 220 volt. . . . . . . . . - • • • . . £4 19 0 BAIRD &TATLOCK (LONDON) LTD. 1152' 1153' 1154' 1155' 1152 Zeiss Binocular Magnifier for stereoscopic observation of small solid objects. Price, with one of the following magnifications . . Magnification — 0.75, i, 2, 2.1, and 3 diameter. Working distance — 30, 22, 9, 7, and 5 cm. Binocular field of view— 14 by 10, n by 7, 6 by 4, 4.5 by 3, 3.5 by 2.5 cm. Illuminating Device for above . . Extra Lenses for either magnification per pair Dry Battery in leather case £1 16 0 1156 SMALT. PROJECTION" Al'PAUA ITS (About | Full Size). (i) Arc Lamp ; (2) Conical Light-proof Connector between the lamp casing and the condenser ; (3) Tfiree- lens Condenser ; (4) Lantern Slide Carrier ; (5) Projection Lens ; ((>) Diaphragm. 1156' Zeiss Small Projection Apparatus for lantern slides, measuring 4$ by 3}, and smaller sixes, with hand regulating 5 amps, arc lamp, suitable for continuous or alternating current. For no volt, current 1157' Zeiss Small Projection Apparatus for 220 volt, current £1 £0 £0 £11 £11 10 16 0 0 CROSS STREET • HATTOTST GARDE1ST, E- C BAIRD & TATLOCK. (LOM)ON) LTD. 1158 1158r Zeiss Telescopic Monocular and Binocular Magnifiers, with a magnification of 3 or 6 diameter, with illuminating device, cable, and dry battery .. From £3 10 0 to £12 13 6' .i 4 5 6 7 a P. MAYKK'S NEW DISSECTING MICROSCOPE (About i Full Size)/ (i) I-cns Holder fitted with rack and pinion ; (2) Composite Dissecting Lens ; (3) Illuminating Mirror : (() Light Modifying Disc ; (5) Set Screw at one corner of the sole frame ; (6) Aplanatic Magnifier (10 diameters) ; (7) I'lutr Glass Disc to drop into stage opening ; (S) Aplanatic Magnifier (6 diameters). 1159 (For price see No. 1159, PaSe ^°- 238}« (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIR.D .ScTATLOCK (LONDON) LTD. I'. MAYKK'S XKW DISSECTING .MICROSCOPE FITTED WITH THE BODY OF STAND Xb ON STRAIGHT PILLAR BRACKET (about J Full Size). (13) Yoke with Traversing Slide Carriage for the Microscope Body ; (14) Body of Microscope Stand Xb ; (15) Straight Pillar Bracket with two sockets for the attachment of the Microscope Body ; the latter is shown attached by the lower socket. 13 1159-1173 1159T Dissecting Stand (fig. 1159 above) with adjustable mirror and light modifying device. Stage, 6 by 8 in. ; round stage opening, 4! in. diameter ; brass disc and plate glass disc to fit opening ; 2 arm rests, and lens holder fitted with rack and pinion . . . . £418 1160r Ditto, with simple sliding lens holder .. .. .. .. .. .. £3 10 The use of above stands as monocular or binocular dissecting microscopes requires accessories specified below. 11611 Yoke with slide carnage for giving traversing motion to the microscope body, with 2 screws . . . . . . . . . . . . . . . . ..£17 1162' Or Yoke, without traversing slide carnage .. .. .. .. £0 11 1163' Body of Binocular Microscope .. .. .. .. £5 10 1164T With Pillar Bracket for attachment to the yoke .. . . extra £010 1165r Or Pillar Bracket, giving inclined position .. .. ,. £080 1166' Body of Single Tube erecting microscope .. .. .. .. .. .. £3 15 0 1167T Ball Stage to drop into stage opening .. .. .. .. . . £0 15 0 1168' Raising Block, for attachment between yoke and pillar bracket, with 2 screws .. .. £076 To which can be added — 1169r Driiner Stereoscope Camera .. .. .. .. £700 1170' Drawing Apparatus for Mayer's dissecting microscope .. .. £650 Paired Objectives, to fit body of binocular microscope. 1171' Water-immersion Price 1172T Paired Huyghenian Eyepieces. Price 11731 Special Eyepieces. 55 a" a- a3 Pl. 45 /- 45/- 45/- 45/- 55/- i -7 3 4 5 12/- 12/- 12{- I2f- 12/- . . Focus 15 g m/m Per Pair 50/- 50/- CROSS STREET • HATTON GARDETST, E- C BAIR-D &TATLOCK (LOM)ON) LTD. HORIZONTAL AND VERTICAL CAMERA WITH MICROSCOPE, IN THE VERTICAL POSITION (About i's Full Size). (Sx) Support for the optical bench ; (L) source of light ; (S) collective lens with iris diaphragm ; (C) light-filter carrier on saddle stand : (Ml microscope ; (K) sliding stop and clamps for fixing the stays. — The position of the camera when investigating the specimens is shown in outline. 1175 . 1 175' The Horizontal and Vertical Camera, with one double dark slide for plates 21 by 21 cm. ; two focussing screens and two camera fronts, one of the latter fitted for light-tight con- nection with the microscope. Bellows extension about i m. Rod of the camera stiffened by two stays. To stand on any steady table about z\ m. in length, or two shorter tables of equal height . . . . . . . . . . . . . . ..£900 1176T Double Dark Slide for 21 by 21 cm. only, without carriers for intermediate sizes of plates £0 18 1177T Plate Carriers for intermediate sizes of plates, as required .. .. .. each £0 1 11781 Repeating Back for making exposure scales or photographs in varied adjustment, also suitable for stereograms. Largest size of plate 21 by 21 cm., without carriers for inter- mediate sizes of plates . . . . . . . . . . . . . . ..£20 1179T Focussing Lens, magnification by 6 .. .. .. .. .. .. £16 1180T Optical Bench, i m. long, to connect with the sole-plate of the camera .. .. £10 11811 Focussing Mount for photographic objectives, to screw on to the second camera front £0 12 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 1174 1174T The Epidiascope, by Carl Zeiss, Jena. Surmounted by large microscopic projection apparatus. (Prices and pamphlet on application.} 1182 Siedentopf Paraboloid Condenser. Dark-ground illumination for the microscopic observation and the instantaneous photo-micrography of living bacteria (including spirochaete pallida). 1182T Nernst Lamp, i ampere, without automatic ignition 1183r Compensating Eyepiece No. 12 11841 Compensating Eyepiece No. 18 After use with cedar wood oil the Paraboloid Condenser should always be cleaned with soft linen saturated with benzole. £2 0 £1 10 £1 5 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &.TATLOCK. (LONDON) LTD. Optical Projection Screens with Metallic Surface. Screens for Optical projection, with metallic surface for coloured and feebly lighted pictures. Within the hist few years optical projection has come very much to the front as a means of instruction ami ertainment, and this valuable and fascinating method of demonstration has now entered upon a stage where it U-rniiirs in many cases a matter of serious difficulty to secure a sufficiently bright picture, whilst 1 here is scarcely possibility of remedying the defect by an improvement of the apparatus itself. As far as the power of tin- i.pncal apparatus and the light producing appliances are concerned we have practically reached the extreme limit of the attainable intensity, and at present there is little or no prospect of increasing the brightness of the picture ( \ri-ptini; by improving the reflecting properties of the screen. An increase in the reflecting power of the screen may be obtained in various ways, e.g. by adopting the principle ot tueinllic reflection, which should, of course, be of the nature of diffuse reflection, since a mirror cannot s-rvc a-, a re screen. It is accordingly necessary to employ in these cases dulled surfaces. (ifl'tiil Projection Screens of this kind are made at the Zeiss Optical Works. These screens have a metallic surface prepared by a special registered process, and are supplied in sizes having very extensive areas. I ln-y are mainly made up of aluminium, which is less readily affected by the chemical influences of the atmosphere than metals, and they may be rolled up. PRICES AND DIMENSIONS OF METALLIC SCREENS (Registered). 1185T Smooth Aluminium Screen, mounted in frame and not made to roll up : 1. Size : 40 by 40 inches 2. ,, 60 „ 60 3. „ 80 „ 80 11861 Seamless Aluminium Shirting Screen, mounted in frame and not made to roll up : 4. Size : 40 by 40 inches 5. ,, 60 „ 60 6. „ 80 „ 80 „ 1187' Seamless Aluminium Shirting Screen, with folding frame, strap ends, and rolling device : 7. Size : 984 by 98^ inches 8. „ 118 „ n8~ „ 1188' Ribbed Aluminium Screen, mounted in frame and not made to roll up: 9. Size : 40 by 40 inches 10. ., 60 „ 60 11. ,, 80 „ 80 1189T Combined Smooth Aluminium and Aluminium Shirting Screen for use on both sides, mounted in frame and not made to roll up : 14. Size : 40 by 40 inches . . . . . . . . . . • 15. ,, 60 „ 60 16. „ So „ 80 1190T Combined Smooth, Shirting, and Ribbed Aluminium Screen with back available for use as an ordinary white screen, mounted in frame and not made to roll up : 17. Size : 40 by 40 inches. Smooth . . 18. ,, „ ,, Shirting . . 19. ,, „ .. Ribbed 20. ,, 60 ,, 60 ,, Smooth .. 21. „ ,, ,, Shirting .. 22. ,, „ ,, Ribbed .. 23. ,, 80 „ 80 „ Smooth .. 24. ,, ,, ,, Shirting . . 25. ,, „ ,, Ribbed Other Screens besides those specified under No. ii8yT are supplied to order. 1191T Tripod Stands of Polished Wood with appliances for attaching, raising, and lowering as well as for turning the screen from side to side are supplied for screens measuring up to : 26. Size : 60 by 60 inches 27. ,, 80 „ 80 „ . . . . £1 15 0 £3 1 0 £4 16 0 £1 15 0 £3 1 0 £4 16 0 £12 10 0 £15 10 0 £1 18 0 £380 £580 £220 £3 18 0 £640 £200 £200 £230 £3 13 0 £3 13 0 £400 £5 16 0 £5 16 0 £680 £100 £2 10 0 .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 241 BAIRD &. TATLOCK (LONDON) LTD. Microscopes by Crouch, London. 1192 1192T The " Opsonist " Microscope. Crouch's, as specified below, in polished teak case This Microscope has been designed to meet the requirements of those preferring a side focussing adjustment in place of the older form. The movement is provided with a cylinder, divided to read to o.ooi mm., and with milled heads on each side of the limb. The coarse focussing adjustment is by means of a diagonal rack and pinion. The stage has vertical and cross traversing adjustments, by quick screw and rack and pinion of 2! in. and i in. respectively (65 mm. by 25 mm.), and the cross traverse is removable so that a plate cultivation, Petri dish, or large section can be examined without difficulty. The convenient application of the high power dark ground method of illumination is also provided for. The substage is perfectly centred to the objectives and condenser supplied with it. Should a centring arrange- ment be necessary, as in the case of the dark ground illuminator, it is fitted to this accessory as the more convenient method in a working or laboratory model. Kither of the three forms of illuminator in use can be fitted to this stand. It is fitted with large mirrors, plane and concave. The foor is of solid brass and the microscope can be inclined at any angle required. When used in the upright position the substage and mirror are conveniently adjustable, and the eye-point nearer the observer, necessitating less stooping. The usual outfit includes three objectives, the J in., J in. N.A. .85, and oil-immersion T',j in., N.A. 1.30, the latter fitted with stop for use with dark ground Illuminator. These eyepieces, magnifying with a tube length of 170 mm. by 4 by 6, and compensating by 8. Abbe condenser, N.A. 1.20, with iris diaphragm, high power dark ground condenser, dust proof triple condenser (all objectives being adjustable to same focal plane, and carefully centred). £26 0 0 CROSS STREET • HATTCHSr GARDETST, E- C BAIRD &TM1OCK. (LONDON) LTD. 1195 1195T Microscope for Bacteriological and Research Work (Crouch's), with the same outfit of objectives, eyepieces, and accessories as Fig. 1192, complete in polished teak case . . 1196T High Power Dark-ground Illuminator, with centring adjustments . . . . extra This Microscope has been constructed lor research, and other work of the highest class in Bacteriology, etc The coarse focussing adjustment is by diagonal rack and pinion, the bearings of which are much wider than ordinarily-made and much more solid and durable. The fine adjustment is effected by the direct action of a left- handed micrometer screw, in contact with a polished hardened steel plate, and when reversed is without " back- lash." The stage movements are of i in. direct and 2j in. cross traverse, the latter being entirely removable for the more convenient examination of large sections, cultivations, etc. It is also provided with a vernier, reading to .01 mm. £26 5 0 £2 14 0 iMlCAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. F BAIRD &TATLOCK (LONDON) LTD. 1199 (Complete in portable case) . 1199 (Erected for use) . 1199T Portable Travelling Microscope (Crouch's), as specified below, complete in case This Microscope has been constructed for H.M. Government, and its stability is equal to that of the less portable models. It is provided with rack and pinion, and fine focussing adjustments ; stage with cross traverse of 2 in. range, graduated to millimetres, with vernier. Two eyepieces by 4 and by 6 ; three objectives, §, J and ^ immersion carefully centred and adjusted to triple nosepiece (dust-proof) ; Abbe stage condenser, with iris-diaphragm high power dark ground illuminator for use with ^-in. or immersion iVin. for the examination of living bacteria, spirochaetes, etc , and is packed so that all accessories are specially protected in leather case as shown. CROSS STREET • HATTO^T GARDEN, E- C 244 BAIRD &.TATLOCK (LONDON) LTD. 1201 1201T Histologist Microscope, new model (Crouch's), is provided with coarse adjustment by diagonal rack and pinion, new direct fine adjustment at the bottom of " limb " as figured, large stage, plain and concave mirrors, and can be fitted with focussing substage as figured. It is provided with iris diaphragm, double nosepiece, two eyepieces, by 4 and by 6 ; objectives, f and ^ in N.A. .085, in mahogany case complete . . . . 1202T Extra Small Pattern Condenser 1203T Substage, with focussing adjustment 12041 TV-in. Oil-immersion Objective, N.A. 1.30 1206T Removable Stage, with adjustments, i and z\ in. . . 12071 Oil-immersion Lens, TV N.A. 1.30 extra £779 extra £0 10 6 £110 £550 1205T The Cambridge Model Microscope (Crouch's). This microscope is of similar construction to that figured, but with plain stage, 4 by 4 in., graduated in each direction with mm. scales as for inches ; focussing substage, plane and concave mirrors, Abbe condenser and iris diaphragm. Two eyepieces, by 4 and by 6 ; objectives, i in. and £, or f and I, adjusted to the same focal plane on a dust-proof triple nosepiece. Complete in polished teak case ...... £13 0 0 £3 15 0 £550 BAIRD &TATLOCK (LONDON) LTD. Microscopes and Accessories manufactured by C. Reichert, Vienna. Agents :— BAIRD & TATLOCK (LONDON) LTD. 1208 1208T Reichert's New Metallographic Microscope, with rack and pinion coarse adjustment, micrometer screw fine adjustment with milled heads at the side reading displacements of o.ooi mm., with centring revolving stage, also with wheel diaphragm, condensing lens, two glass screens, and i light-filter trough in a tube fitting A. Objectives. Objective No. 2. Apochromatic Objectives. Attachable and Recording Mechanical St 1209 16 mm. 8 mm. £o 17 o £300 £450 B. Apochromatic Immersion Lens, 2 mm. £12 10 4 mm. £550 C. Compensating Eyepieces, Nos. 4 /o 16 D. Micrometer Eyepiece, No. III. 6 - 16 3 mm. £5 15 ' £o 16 o £21 0 0 = £31 12 0 = £28 £0 12 The outfit as specified above £55 12 0 1209' Attachable and Recording Mechanical Stage for Microscope No. 1208, giving two motions at right angles to one another, the ranges of the respective motions being 30 mm. The magnitudes of the motions can be read with the aid of scales and verniers, and hence the position of any given element may be recorded and found without searching extra £4 Outfit for Micro-photographic Work, see page 247. 5 0 CROSS STREET • HATTOTST GARDEN, E-C 2*6 RAIRD &TATLOCK (LOM)ON) LTD. 1210-1215 New Metallographic Apparatus with the Reflecting Camera. 12101 Reichert's New Metallographic Microscope with objectives, eyepieces, and mechanical stage as specified No. 1208,\ to D and 1209 .. .. .. £5917 0 Accessories for Microphotographic Work, {or use with Reichert's Metallographic Microscope, Fig. No. 1208. 1211' Large Base Plate with two optical benches, microscope base, and photo-microphotographic camera, the latter being provided with a ground glass, and plain plate glass focussing screen, and a dark-slide to take 13 by 18 cm. (7^ by 5 in.) ; plates and carriers to take 9 by 12 cm. (4 J by 3 J in.) plates .. .. .. .. £870 1212' One Extra Double Dark-slide .. .. .. .. .. £110 1213' Hooke's Key for focussing from a distance .. .. .. £0 10 0 1214'1' The photo-microphotographic camera can be provided with the focussing mirror shown in Fig. 1214 below at an extra cost of . . £3 15 0 1215' Projection Eyepieces, Nos. 2 and 4, each £2 o o, specially recom- mendable for photo-microphotographic work . . . . . . £400 C.REICHERT WIEN. M M £77 10 0 1214 (focussing mirror) . BAIRD &. TATLOCK (LONDON) LTD. Th 1221 Drawing Apparatus (Fig. A.) (See No. 1219.) Reichert's Microscope. New large stand AI, with extra wide tube and new lateral micrometer-screw. In this instrument the stage is of an unusually large size (120 mm. =4f inches) in diameter so mechanical stage No. 1209, which fits above the rotating sta°e w^ C°arSe adjustment is effected ^ a rack and Pinion movement, the fine adjustment by the new micrometer sere w 1216T Price of the complete stand with swing-out condenser and two iris diaphragms 1217T With the mechanical stage No. 1209 1218T With circular mechanical stage No. 1245 1219- Microscope Stand, No. 1216, with triple nosepiece, objective i b, apochromatic objectives Tim., 8 mm., 4 mm., 2 mm., oil-immersion, numerical aperture 1.35, compensating eyepieces 2, 4, 6 with micrometer, 8, 12, 18, drawing apparatus Fig. A £15 0 0 £19 5 0 £20 0 0 £51 2 0 1220T Microscope Stand, No. 1216, with triple nosepiece, objectives 2, 4 6at 8at A in oil on numerical aperture 1.35, eyepieces II., III., IV. magnifications 20—1200 £31 6 0 1221T Microscope Stand, No. 1216, with triple nosepiece, objectives 3, 7a TV in oil-imr numerical aperture 1.30, eyepieces II., IV. magnifications 40-1200 . . £23 15 0 1222' Additional cost of mechanical stage No. 1209 for the above sets Nos. 1219 to 1221 £450 1223- Additional cost of mechanical stage fig. 1245 for the above sets Nos. 1219-1221 . . £500 RAIRD dcTATLOCKL (LONDON) LTD. Tu 1224-1225 1231-1234 1235 1224T Reichert's Microscope. New Large Stand B. This stand is of smaller dimensions throughout than A I. It is fitted with the new encased and protected micrometer movement and has a circular movable stage no mm. = 4* inches in diameter. The stand has a large illuminating apparatus with rack and pinion focussing movement and an Abbe condenser with cylinder stops, with swing-out condenser and cylinder iris diaphragm, triple nosepiece, objectives 2, 4, 6af, Saf, TV in. oil-immersion, numerical aperture 1.30, eyepieces II., IV., magnifications 20 — 1200 . . 1225T Reichert's Microscope, No. 1224, with triple nosepiece, objectives 3, ya, ,<$ in. oil- immersion, numerical aperture 1.30 ; eyepieces II., IV., magnifications 40-1200 1231' Reichert's Microscope, New Stand C, with large circular stage of 105 mm. = 4^ inches diameter and with exceptionally large stage clearance, the frame being set back and forming a convenient handle. The upper body inclines to 45°. The stand has a rack and pinion coarse adjustment and a micrometer screw fine adjustment, an Abbe condenser (B) with iris diaphragm and plane and concave mirrors, triple nosepiece objectives 2, 4, 6, 8a, TV in. oil-immersion, numerical aperture 1.30, eyepieces II., IV., magnifications 20 — 1200 . . . . . . . . . . . . . . 1233' Reichert's Microscope (Stand C), without condenser, with large cylinder diaphragm, lateral screw, prismatic and micrometer screw; with double nosepiece, objectives Nos. 3 and ya ; eyepieces I. and III. £25 11 0 £19 10 0 1234' Reichert's Microscope (Stand C), No. 1231, with triple nosepiece, objectives 3, 7a, oil-immersion, numerical aperture 1.30, eyepieces II., IV., magnifications 40 — 1200 n. 1235T Reichert's Microscope (Stand H III.), without condenser, with large cylinder diaphragm.. lateral screw and new pattern Austrian foot, with double nosepiece, objectives Nos. 3 and ja, eyepieces I. and III. .. .. .. .. .- •• .. 1236' Reichert's Microscope (Stand H III.), similar to No. 1235, but without condenser, handle, and tilting lever ; with round tilting pillar, large cylinder diaphragm, and lateral screw, objectives Nos. 3 and 7a, eyepieces I. and III., and double nosepiece . . . . £17 7 0 £7150 £14 0 0 £7 10 0 £8 5 0 249 BAIRD &TATLOCK (LONDON) LTD. 1238 Erected for use. 1238 In portable case. 1 ' 1238r Reichert's New Travelling Microscope. This stand is inclinable and has an upper body of magnalium. The frame is bowed so as to form a convenient handle, and is fitted with a rack and pinion coarse adjustment and with tli£ new encased micro- meter adjustment as in stand AI. The illuminating apparatus consists of an Abbe condenser, Type B, with a lateral helical focussing screw and plane and concave mirrors. The microscope is accommodated in a very small case, its dimensions being 29 by 19 by 9 cm. = ii'! by 7| by 3? inches, and its weight about TO Ibs. Withyitt objectives, eye- pieces, and nosepiece £9 4 0 1239T Reichert's Microscope, as above, but with micrometer screw adjustment as in Stand C. . £7 14 0 1240' Reichert's Travelling Microscope, No. 1238, with doubje nosepiece, objectives 2, 4, 6af, 8af, Jj in. oil-immersion N.A. 1.30, eyepieces II., IV., magnifications 20 — 1200 . . £22 15 0 12411' Reichert's Travelling Microscope, No. 1238, with double nosepiece, objectives 3, 7a, jV in. oil-immersion, N.A. 1.30, eyepieces II., IV., magnifications 40 — 1200 . . £17 14 0 1242' Reichert's Travelling Microscope, No. 1239, with double nosepiece, objectives 3, ya, Jj in. oil-immersion, N.A. 1.30. eyepieces II., IV., magnifications 40 — 1200 . . . . £16 4 0 1243' Reichert's Travelling Microscope, No. 1239, with double nosepiece, objectives 3, '/a., eyepieces II., IV., magnifications 40 — 650 .. .. .. .. .. £11 4 0 CROSS STREET • HATTCTrSr GARDETST, E'C BAIBD &.TATLOCK (LONDON) LTD. 1245 1249 Mechanical Stages (a) for Stands AI. 1244* Mechanical Stage for attachment to the fixed stage of the microscope by a screw. The instrument gives a large motion, the travel being 30 mm. = i J- inches in one direc and 85 mm. = 3f inches at right angles to it (see fig. 1209, page 246) 1245- Circular Mechanical Stage, divided into 360 degrees. This stage is readily interchangeable for the ordinary stage supplied with the microscope. By means two milled heads aa', arranged in close proximity, the object may be displaced with case and precision within a range of 40 mm. = i? inches in one direction, and 21 mm. = | inches at right angles to the latter £450 £500 1249' Reichert's New Medium Sized Dissecting Microscope, with handle for the convenient use of the instrument and prolonged base, rack and pinion adjustment, large brass st and base, movable plane mirror and two hand rests, covered with leather, s £2 10 doublets magnifying 10 times, in mahogany case . . 1250' Ditto, but with large glass stage plate and movable lens carrier for examining large pre- ^ ^ parations without moving them . . 1251 ' Reichert's Large Dissecting Microscope for the examination of brain sections and other large or small Objects. The stand has a large stage with glass plate (10 by 10 cm = 4 by 4 inches), which may be replaced by a metal plate. The lenses magnify 6 and 10 ^ ^ times. In mahogany case 1252' Reichert's Huyghenian Eyepieces for Achromatic Objectives. Number of Eyepiece I. II. III. IV. V. Foca! Length inches mm 2 50 If 40 i*1 30 i 25 f 20 Eyepiece magnification Price 3 5/- 4 5/- 5-5 51- 5/- 9 51- BAIRD &TATLOCK (LONDON) LTD. 1253T Reichert's Achromatic Objectives. Number of Objective. Equivalent Focus in millimetres. Equivalent Focus in inches. Numerical Aperture. Price. ( OO 50.0 2* £0 13 0 o / 1 £090 la j- 40.0 if 1 £0 17 0 ib 39—27 if-i* 0.06 — o.io £150 I 1 < £090 2 I 30.0 ij 0.17 -( £0 17 0 3 18.5 3 0-34 £0 15 0 4 8 i O.50 £150 " Dry " Objectives 4b 4c f I2.I i 0-35 £150 £0 17 0 5 5-2 A 5 0.77 £150 6 I £1 10 0 6a| 4-3 I £2 12 0 6b| I £1 10 0 7a 3-2 * 0.88 £1 10 0 8a 2.8 i7 0.90 £200 8af 2.8 17 0.90 £2 12 0 - 9 9* 2.O A 0-95 ) £2 12 0 £3 12 0 Water Immersion Objectives 10 10* I ,.8 A 1. 10 — 1.20 | £3 12 0 £4 12 0 / 18 1.8 i T3" | \ £750 New Semi-apochromatic if) i-3 A 1 T-35 1 £10 0 0 Objectives i6b 2.25 A I £450 (homogeneous immersions) :8b r.8 A 1.30 J £500 igb 1.25 A 1 I £7 10 0 * With cover glass correction. f With extra long working distance for counting blood corpuscles. J With fluorite lenses. PRICES AND MAGNIFICATIONS Of Reichert's Apochromatic Objectives and Compensating Eyepieces No. 1255. 1254' Reichert's Apochromatic Objectives. Magnifica- Magnifications of Objectives with Focal length. Numerical Objectives Compensating Eyepieces. Price. Aperture. without inches mm Eyepieces. 2 4 6 8 12 18 f § i6f 0.30 15.5 31 62 94 125 I87 281 £300 " Dry " i 8ft 0.50 31 62 125 186 250 375 ^62 £450 Objectives. J 4tt* 0-95 63 125 250 372 500 750 1125 £650 i 3tt* 0-95 85 I/O 340 502 680 IOOO 1800 £6 15 0 Immersion 1 ^ 2ttt I.30—I.35 125 250 500 75« IOOO 1500 2250 £12 10 0 Objectives. j ¥ 2ttt i-5ttt 1.40 I.30—I.35 125 165 250 330 500 650 750 IOOO IOOO 1300 1500 2000 2250 3000 £17 10 0 £15 0 0 * With coverglass correction. t- tt> ttt» indicate respectively the number of fluorite lenses present in the objective. CROSS STRET • HATTOTST GARDE1ST, E-C BAIRD &.TATLOCKL (LONDON) LTD. 1255' Reichert's Compensating Eyepieces. Numbei .... 2 4 6 Price .. £0 16 0 £0 16 0 £0 16 8 6 12 5 0 £0 16 0 £160 £150 A1255' Compensating Eyepiece 6 with fixed glass micrometer, 10 mm. divided into 100 parts. 1256' Reichert's Eyepieces for Photomicrography and Projection. Number of Eyepiece . . . . 2 4 0 Price £2 2 0 £2 0 1257 1258 12571' Polar F/4. Reichert's Universal Anastigmatic Objective for Photo -micrography, Projection, and Cinematograph Work. Number i 2 inches . . i i 2 mm. 30 £3 0 0 £3 50 4 0 £3 3 3 75 16 0 4 4 100 £4 5 Focal length Price Diameter of field of view = focal length. 1258T Reichert's Abbe Spectroscopic Eyepiece with direct vision Amici prism. The eye-lens can be accurately focussed upon the slit and the latter is adjustable in length and width. The instrument is provided with a comparison prism, side stage, mirror, and detachable wave-length scale. When the slit is opened the object may be seen with the eyepiece. Complete with specimen tubes, in case . . . . . . . . . . each 1259' Reichert's Double Revolving Eyepiece, II. and IV. 1260T Reichert's Triple Revolving Eyepiece, II., III., IV. 1261' Reichert's Double Nosepiece £1 £1 18 0 £9 0 £0 16 £0 19 0 £0 15 0 A 1262 B 1262T Reichert's Triple Nosepiece, either pattern A or B . . . . each 1263T Reichert's Quadruple Nosepiece Microscopes fitted with nosepieces should have a rack and pinion coarse adjustment. They are not intended for the smallest stands. £100 £150 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 253 BAIRD &. TATLOCK (LONDON) LTD. Bausch & Lomb's Microscopes and Accessories. I 1264-1267 BAUSCH & LOMB'S MICROSCOPE, PATTERN BH. Base. Horse-shoe form. Pillar. Round ; provided with inclination joint, having vertical and horizontal stops. Arm. Handle type ; grooved at base for attachment of mechanical stage A ; provides ample space for manipula- tion of object. Body Tube. Outside diameter, 35 mm. ; provided with society screw thread ; standard size eyepieces are used ; draw tube graduated in single millimeters with every tenth line numbered, adjustable in cloth-lined sleeve, or in metal fitting, if so specified and provided with society screw thread for the use of low power objectives. Focussing Adjustment. Coarse adjustment by standard rack and pinion ; fine adjustment of our lever type with two-sized milled head for slow and rapid movement. Stage. Of metal, covered with vulcanized rubber ; measures 103 by 101 mm., with a distance of 59 mm. from centre to base of arm ; provided with spring clips, and iris diaphragm so mounted as to be readily detached if desired and screw threads for attaching a substage ring to hold an Abbe condenser. Mirror. Plane and concave, 50 mm. in diameter ; adjustable in two planes in a fork, mounted on a swinging arm for oblique illumination. Finish. Body tube, with connections, and pinion, milled heads in light lacquer ; other parts, including draw- tube, unless metal fitted, in black. Black body tubes will be furnished in .place of light lacquer, if so specified, without additional cost. Case. Of hard wood with polished finish ; fitted with brass lock and key. No. Objectives. Eyepieces. Nosepieces. Price Dry. 1264' BH 1 1 6 mm. 4 mm. 7-5 X £5 14 6 1265' BH 2 16 mm. 4 mm. 7-5 X Circular Double £699 1266' BH 3 16 mm. 4 mm. 5X 10 x £5 19 6 1267' BH 4 16 mm. 4 mm. 5X 10 x Circular Double £6 14 6 Microscope BH will be furnished with a substage ring and Abbe condenser, 1.20 N.A., at an additional cost. CROSS STREET • HATTCTN GARDEN, E-C 254 BAIRD &TATLOCK (LONDON) LTD 1270-1275 Microscope BB. (Bausch & Lomb's). 1268-1269 Microscope BH, with Screw Substage. BAUSCH & LOMB'S MICROSCOPE, PATTERN BH 6 & 8. This instrument is the same as our regular microscope BH with the addition of a substage, adjustable for ith the objective if desired i ne su No. Objectives. Eyepieces. Nosepiece. Abbe Condenser. Price. Dry. Oil Immersion. 1268T 1269' BH6 BH8 i6mm. 4mm. i6mrn. 4mm. 1.9 mm. 5X 10 X 5X 10 X Circular Double Circular Triple 1.20 N.A. 1.20 N.A. £846 £13 9 6 BAUSCH & LOMB'S MICROSCOPE, PATTERN BB. No. Objectives. — " Eyepieces. Nosepieces. Abbe Condenser. Price. Dry. Oil Immersion 1270' 1271' 1272' 1273' 1274' 1275r BB 1 BB 2 BB 3 BB 4 BB 6 BB 8 16 mm. 4 mm. 16 mm. 4 mm. 16 mm. 4 mm. 16 mm. 4 mm. 16 mm. 4 mm. 16 mm. 4 mm. 1.9 mm. 7-5 X 7-5 X 5X 10 x 5X lox 5X 10 x 5X 10 x Circular Double Circular Double Circular Double Circular Triple 1. 2O N.A. 1.20 N.A. £7 12 0 £870 £7 17 0 £8 12 0 £9 17 0 £15 2 0 Special Swing-out Condenser The last two prices above include an Abbe condenser .^ "^^ swing-out mounting with upper and lower ins diaphragms will be subst When ordering this mounting, please specify screw substage with swing- A in the new ^ost of 21,-. J BAIRD &TATLOCK (LONDON) LTD. Base. Horse-shoe form. 1276-1281 MICROSCOPE BBH (BAUSCH & LOME'S). Pillar. Round ; provided with inclination joint, having vertical and horizontal stops. Arm. Handle type ; grooved at base for attachment of mechanical stage A ; provides ample space for manipu- lation of object. Body Tube. Outside diameter, 35 mm. ; provided with society screw thread ; standard size eyepieces are used (No. 1344) ; draw tube graduated in single millimetres with every tenth line numbered, adjustable in cloth-lined sleeve, or in metal fitting, if SO specified, and provided with society screw thread for the use of low power objectives. Focussing Adjustment. Coarse adjustment by standard rack and pinion ; fine adjustment of our lever type with double milled micrometer screw head for slow and rapid movement, the larger part graduated into 100 divisions, each equal to .0025 mm. in vertical movement, and provided with a hinged indicator, which may be turned back from the head. Stage. Of metal, covered with vulcanized rubber ; measures 120 by 107 mm., with a distance of 70 mm. from its centre to base of arm ; provided with spring clips. Substage. Adjustable for focus by a quick-acting screw ; consists of a mounting for the Abbe condenser aad an iris diaphragm, which comes into the plane of the stage when the screw is turned up as far as possible, allowing the condenser to be used in immersion contact with the objective, if desired ; substage is swung to the left of the optical axis when screw reaches the limit of motion downward. No. Objectives. Eyepieces. Nosepieces. Abbe Condenser. Price. Dry. Oil Immersion. 12761 BBH 1 16 mm. 4 mm. 7-5 x £8 13 0 1277' BBH 2 16 mm. 4 mm. 7-5 x Circular Double £980 1278T BBH 3 16 mm. 4 mm. 5X 10 x £8 18 0 1279' BBH 4 16 mm. 4 mm. 5X 10 x Circular Double £9 13 0 1280' BBH 6 16 mm. 4 mm. 5X 10 x Circular Double 1.20 N.A. £10 18 0 1281' BBH 8 16 mm. 4 mm. 1.9 mm. 5X 10 x Circular Triple 1.20 N.A. £16 3 0 Special Swing-out Condenser. The last two prices above include an Abbe condenser in ordinary mounting. An Abbe condenser, 1.20 N.A., in the new swing-out mounting with upper and lower iris diaphragms, will be substituted for the regular one at an additional cost of 21/-. When ordering this mounting, please specify "screw substage with swing-out condenser." CROSS STREET • HATTCW GARDE1ST, E-C 256 BAIRD &TATLOCK (LONDON) LTD. Base. Horse-shoe form. 1282-1286 MICROSCOPE CAM (BAUSCH & LOME'S) Pillar. Rectangular in section ; provided with inclination joint and clamping lever to secure instrument in any position, and with stops in the vertical and horizontal positions. Arm. Handle type ; of enlarged design, providing ample space for manipulation of any object desired ; grooved at base for mechanical stage A. Body Tube. Outside diameter, 39 mm. ; provided with society screw thread ; standard size eyepieces are used No. 1344; draw tube graduated in single millimetres with every tenth line numbered, adjustable in cloth- lined sleeve, or in metal fitting, if so specified, and provided with society screw thread for the use of low power objectives. Focussing Adjustment. Coarse adjustment by standard rack and pinion ; fine adjustment of our lever type with knurled micrometer screw head in two parts of different diameter for slow and rapid movement, the larger graduated into 100 divisions, each equal to .0025 mm. in vertical movement, and provided with a hinged indicator, which may be turned back from the milled head. Stage. Of metal, covered with vulcanized rubber ; measures 125 by 115 mm. with a distance of 75 mm. from its i iMitre to base of arm ; provided with spring clips. Substage. Complete with swing-out condenser, and so arranged that all substage accessories, inserted into the upper sleeve, may be easily employed ; adjustable by standard rack and pinion ; upper iris diaphragm of dome shape, self-locking, combined with Abb6 condenser, the whole easily removable from substage ; Abbe condenser removable from optical axis by a double swing movement to one side, releasing upper iris diaphragm for use; lower iris diaphragm adjustable laterally by rack and pinion for oblique illumination, revolvable about its own axis and mounted on a swinging arm, allowing it to be swung entirely out of the optical axis. No. Objectives. Eyepieces. Nosepieces. Abbe Condenser. Price. Dry. Oil Immersion. 1282' CAH 1 16 mm. 4 mm. 7-5 x 1.20 N.A. £15 16 9 1283' CAH 2 16 mm. 4 mm. 7-5 x Circular Double 1.20 N.A. £16 11 9 1284' CAH 3 16 mm. 4 mm. 5X IQX 1.20 N.A. £16 1 9 1285' CAH 4 16 mm. 4 mm. 5X 10 x Circular Double 1.20 N.A. £16 16 9 1286' CAH 8 16 mm. 4 mm. 1.9 mm. 5X 10 x Circular Triple i. 20 N.A. £22 1 9 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 257 ST. BAIRD & TATLOCK. (LONDON) LTD. 1287-1289 CHEMICAL MICROSCOPE M (BAUSCH & LOME'S). SPECIFICATIONS. Base. Horse-shoe form. Pillar. Round ; provided with inclination joint, having vertical and horizontal stops. Arm. Handle type ; provides ample space for manipulation of object. Body Tube. Outside diameter, 35 mm. ; provided with society screw thread ; draw tube graduated in single millimetres with every tenth line numbered, adjustable in cloth lined sleeve, and provided with society screw thread for the use of low power objectives. Focussing Adjustment. Coarse adjustment by standard rack and pinion ; fine adjustment of our lever type with two-sized knurled head for slow and rapid movement, ceasing to operate if objective touches the slide. Stage. Circular, revolving with knurled edge, graduated on circumference in single degrees, with every tenth line numbered, and read by a conveniently placed pointer ; measures 88 mm. outside and 78 mm. inside graduations with a distance of 58 mm. from centre to base of arm ; has vulcanite top and is provided with spring clips and centring screws. Substage. Adjustable for focus by quick-acting screw of long range ; consists of a mounting for the polarizer, which is swung to the left of the optical axis when screw reaches the limit of motion downward Analyzer. Consists of a Thompson prism mounted in a revolving collar graduated in two-degree divisions with every tenth line numbered ; collar revolves smoothly in cylindrical mounting fitting over draw tube and is slotted to engage stud for zero point ; can be easily removed for insertion of microscope eyepiece. Polarizer. Consists of a high grade Nicol prism mounted with a revolving ring graduated in two-degree, divisions, with every tenth line numbered, and having an indicating pointer ; entire mounting securely supported in sub- stage and fixed for zero point by stud which engages corresponding slot. Mirror. Plane and concave, 50 mm. in diameter ; adjustable in two planes in a fork, mounted on a swinging arm for oblique illumination. Finish. Brass Lacquered with block stand. Case. Of hard wood with polished finish ; fitted with brass lock and key. No. Objectives. Dry. Cross Hair Eyepieces. Quick changing Nosepiece. Price. 1287'' 1288' M 1 M 2 16 mm. 8 mm. 16 mm. 8 mm. 10 x 15 x 10 X 15 X With Two Rings £17 10 9 £18 17 9 1289' M 4 32 mm. 16 mm. 8 mm. I 5X 7-5X1 jiox 15x7 With Three Rings £20 16 8 CROSS STREET : HATTCTlSr GARDEN EC 258 " BAIRD &.TATLOCK (LONDON) LTD. 1290-1294 Doublet Magnifiers (Bausch & Lomb's) . Composed of two separated piano convex lenses in three styles of metal mounting. Give satisfactory results and are recom- mended for use wherever a good lens is wanted at a very reasonable cost. F F Working Diameter of No. Magnification. Distance. Field. Mounting. Price. mm. in. mm. in. mm. in. 1290' 1 38 I A 7X 2O.3 H 18 » For Dissect. Micro. £029 1291' 2 25 I 10 X 20.1 H 16 iii .i ii ii £029 1292' 1293' 1294' 3 6 n M M H vO O vO j t 1 t J 14 X I4X 8.9 8.9 8.9 eoiojrtocwlco 10 IO 10 1 I l Hand Magnifier with Hex- agonal Handle Folding Pocket Case £029 £029 £039 E. F. = equivalent focal length. 1295-1302 Coddington Magnifiers (Bausch & Lomb's) . Composed of a cylinder of glass, with a deep groove cut in at equal distance from the ends, acting as a diaphragm. The ends of this cylinder are ground spherically to form the lens surfaces. These magnifiers give good definition and wide field, although, owing to construction of the lens, the corrections are not of the order of the Hastings Triplets or Triple Aplanats. Furnished in two styles of metal mounting, engraved " Coddington " with the focus. No. E.F. Magnifica- Working Distance. Diameter of Field. Mounting. Price. mm. in. mm. in. mm. in. 1295' 163 38 I* 7X 28. I* 30 iA Folding Case £056 1296' 162 25 I 10 x 18.8 20 iT;k £056 1297' 161 ! 14 X 14.1 0 14 A tt it £056 1298T 160 13 I 20 X 8.4 6 8 A tt it £056 1299' 163A 38 Ii 7X 28. ij 30 H For Dissect. Micro. £049 1300' 162A 25 I iox 18.8 i 20 11 tt tt £049 1301r 161A 19 1 14 x • 14.1 A 14 8 T* tt tt >.- £049 1302' 160 A 13 i 20 X 8-4 A 8 A •> il f> £049 1 EMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 259 BAIRD &TATLOCK. (LONDON) LTD. 1303-1310 Triple Aplanats (Bausch & Lornb's) . Composed of two meniscus lenses of flint glass, separated by a double convex lens of crown glass. Field is large and has a perfect correction for chromatic aberration, as well as for flatness, astigmatism and distortion. These magnifiers are of new construction, and we recommend them for the highest class of work. Their working distance is a little short of a simple lens of the same focus. Furnished in two styles of metal mounting, engraved " Triple Aplanat " with the focus. Working Diameter of No. Magnifica- Distance. Field. Mounting. Price. tion. mm. in. mm. in. mm. in. 1303T 168 34 ii 7-5 x 29-5 IT"* 28 I* Folding Pocket Case £0 15 0 1304T 167 25 i 10 x 22.0 I 20 tt a » » £0 15 0 13051 166 17 1 15 X 15.0 *f 14 8 TW >i t> a £0 15 0 1306* 165 13 i 20 X II. 0 A 8 I IV a >t a £0 15 0 13071 168 A 34 i| 7-5 x 29-5 rft 28 4 For Dissect. Micro. £0 15 0 1308T 167 A 25 i 10 X 22. 0 i 20 « a a a £0 15 0 1309T 166 A J7 1 15 X 15.0 ^ M A ,i a a £0 15 0 1310T 165A 13 i 20 X II.O A 8 5 Tff ,, £0 15 0 E. F= equivalent focal length 1311-1317 Hastings Aplanatic Triplet Magnifiers (Bausch & Lomb's). After formulae by Prof. Charles S. Hastings, Sheffield Scientific School, Yale University. These magnifiers are among the most perfect produced. Their excellent corrections have always been appreciated by scientists. The angle of view embraced is very large and the working distance almost equal to that of a simple lens of the same focus. Furnished in two styles of metal mounting, engraved " Hastings Triplet " with the focus. ET? Working Diameter of No. Magnification. Distance. Field. Mounting. Price. mm. in. mm. in. mm. in. 1311' 173 38 4 7X 33-6 IA 30 iA Folding Pocket Case £183 1312r 172 25 I 10 X 22.0 I 20 H »» » » £1 8 3 13131 171 J9 1 14 x 16.5 I* 14 a TV » » tt £183 1314' 170 13 i 20 X II. 2 A 8 T? »» >J » £183 1315' 173 A 38 Ij 7X 33-6 IT5* 30 IT3F For Dissect. Micro. £183 1316' 172 A 25 I 10 X 22. 0 g 20 « » >i i» £183 1317T 171A 19 I 14 X 16.5 H- 14 e Ttf i> » Ji £183 260 BAIBD ^lATLOCK (LONDON) LTD. 1319 (Stand TU) 1319' Stand for Dissecting Lenses (Bausch & Lomb's) Price £0 11 3 Base. Of heavy metal, 98 mm. in diameter. Post. Height, 172 mm. ; polished to permit easy sliding adjustment of lens arm connection. Lens Arm. One piece with spring clamp at end which will hold any lens not more than 38 mm. in diameter ; maximum distance from centre of pest to centre of lens, 205 mm. ; may be rotated vertically to place lens at any desired angle. Adjustments. Two, vertical on post for focus, and lateral, both controlled by convenient thumb screws. 1320 (Stand TUS) 1320T Stand for Dissecting Lenses (Bausch & Lomb's) Price £1 13 9 Base. Of heavy metal, 122 mm. in diameter. Pillar. Round metal, 95 mm. from top to base. Lens Arm. In three parts with three joints ; attached to triangular post by strong joint with broad bearing surface ; maximum distance from centre of pillar to centre of lens, 340 mm. ; spring clamp will hold lenses not exceeding 38 mm. in diameter. Adjustments. Vertical, for focus, by rack and pinion, with range of 48 mm. ; first two joints of lens arm con- trolled simultaneously by single winged nut at first joint ; third part of lens arm, the lens holder, adjustable through 30 mm. to and from second part of arm, and secured in any position by thumb screw ; may also be rotated vertically to place lens at any desired angle ; entire arm revolves about the pillar. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &. TATLOCK. (LONDON) LTD. 1321 1321T Pocket Dissecting Microscope S. (Bausch &Lomb's). With one doublet lens Stand. Mahogany box, measuring 102 by 65 by 45 mm. ; reversible cover slides in groove, with stage and lens mounting on under side — inverted, microscope is in position for use, right side up, box is closed. Lens. Doublet, No. i, 2 or 3 regularly supplied ; lens arm also will hold any of our regular magnifiers — Hastings, Triple Aplanat or Coddington (see Nos. 1290-1318). Lens Arm. Swings across field on revolving post, adjustable for focus ; distance from centre of post to centre of lens, 35 mm. Stage. Glass, 44 by 40 mm. ; fits in grooves in wooden supports, attached to cover ; black and white metal plate also supplied for use as opaque background. Mirror. Plane, 44 by 40 mm. ; set at proper angle beneath stage, in same wooden supports. £076 1322-1323 Dissecting Microscope T. (Bausch & Lomb's). After design of Dr. Charles R. Barnes. 1322T No. T 1. With one doublet lens .. 1323T No. T 2. With two doublet lenses Stand. Block of wood, neatly finished and fashioned to provide hand rests ; bottom measures 250 by 90 mm. ; base is hollowed and hinged to constitute suitable case for accessories. Lens. Doublet No. i , 2, or 3 regularly supplied ; lens arm also will hold any regular magnifier — Hastings, Triple Aplanat or Coddington. Lens Arm. Swings across field on revolving post, adjustable for focus ; distance from centre of post to centre of lens, 50 mm. Stage. Glass, 80 by 70 mm., removable ; black and white metal plate also supplied for use as opaque back- ground. Mirror. Plane, 75 by 72 mm. ; mounted at proper angle in grooves beneath stage and removable. £096 £0 12 3 CROSS STREET • HATTQN GARDEN, E-O 262' BAIRD &TATLOCK (LONDON) LTD. 1324-1329 Dissecting Microscope W. (Bausch & Lomb's). This model is similar to Model U in its dimensions, differing in its focussing adjustment and in being regularly supplied with hand rests, as shown in the illustration. The focussing adjustment is by standard rack and pinion, with a knurled head on either side, giving a range of 60 mm. The hand rests are of metal, neatly covered with leatherette, 95 mm. in length and detachable. The Compound Erecting Body can be satisfactorily used with this stand, being substituted for the lens arm. We only recommend stands with rack and pinion adjustments for use with this instrument. Folding pocket rests are included in prices quoted. Lenses. M. Focal Lengths. Formulas. 1324T W 1 25 mm. Doublet £1 17 6 1325' W 2 38 mm. 19 mm. Doublet £2 0 3 1326' W 3 25 mm. Coddington £1 19 6 1327r W 4 38 mm. 19 mm. Coddington £2 4 3 1328' W 5 25 mm. Triple Aplanat £2 9 9 1329' W 6 25 mm. 13 mm. Triple Aplanat £3 4 9 |f]CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. '. ^TO-_ ^5=5«fe"«^^ BAIRD &TATLOCK (LONDON) LTD. 1330-1337 Dissecting Microscope Y. (Bausch & Lomb's). Base. Metal ; horse-shoe form. Pillar. Round; of metal ; 114 mm. from top to base. Lens. Doublet, Coddington, Triple Aplanat or Hastings Triplet regularly supplied. Lens Arm. Jointed so that entire field of stage can be covered ; maximum distance from centre of pillar to centre of lens, 90 mm. ; arm may be removed for substitution of erecting body ; extra removable support provided for attachment of Abbe Camera Lucida, which may be raised or lowered to get full field of view. Focussing Adjustment. By standard rack and pinion, with a knurled head on either side ; range 60 mm. Stage. Plate glass, 90 by 80 mm., removable ; second set of grooves beneath stage for black and white metal plate, supplied for use as opaque background ; extra long spring clips attached to stage support ; holes for hand rests in edges of stage support. Hand Rests. Mahogany, 160 mm. long ; attached to edges of support and steadied by metal frames ; detach- able but included in outfits. Mirror. Plane and concave, 65 mm. in diameter ; mounted on swinging arm. Case. Of wood, neatly finished and fitted with catch. Lenses. No. Price. Focal Lengths. Formulae. 1330T Y 1 25 mm. Doublet £3 10 9 1331T Y 2 38 mm. 19 mm. Doublet £3 13 6 1332* Y 3 25 mm. Coddington £3 12 9 1333* Y 4 38 mm. 19 mm. Coddington £3 17 6 1334* Y 5 25 mm. Triple Aplanat £430 1335* Y 6 34 mm. 17 mm. Triple Aplanat £4 18 0 1336* Y 7 38 mm. 19 mm. Hastings Triplet £646 1337* Y 8 38 mm. 19 mm. Hastings Triplet £820 264 BAIRD &TATLOCK (LONDON) LTD. 1338 Revolving Nosepieces. 1339 1340 1341 Uuless otherwise ordered, we supply nosepieces of circular form, which are absolutely dust-proof in any position of the objectives, revolve easily, register accurately, are of light weight, engraved with the equivalent focus of the lives to be used and finished neatly in durable black lacquer-to prevent reflections. A great advantage is found in the fact that on these nosepieces we adjust our objectives so that they are accurately centred and par-focal, enabling the user to change from one to the other with only a slight amount of re( 1.02 mm. 0.90 mm. 0.83 mm. 0.85 mm. 0.67 mm. A Q 215 x 275 X 320 X 430 X 560 X 43 0.48 mm. 0.43 mm. 0.39 mm. 0.40 mm. 0.32 mm. £*7 285 x 365 x 420 X 570 x 740 X 57 0.36 mm. 0.32 mm. 0.29 mm. 0.30 mm. 0.24 mm. 10 AC 475 X 6iox 720 X 950 X 1260 X 1.9 95 0.22 mm. 0.19 mm. 0.17 mm. 0.18 mm. 0.14 mm. I c 128 640 X 802 x 960 X I280X 1650 X J 0.17 mm. 0.15 mm. 0.14 mm. 0.14 mm. o.n mm. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &.TATLOCK (LONDON) LTD. POLARIZING APPARATUS, &c., FOR BAUSCH & LOME'S MICROSCOPES. 1346-1347 1348 1349 1345' Stage Micrometers. These micrometers consist of glass slides, measuring 75 by 25 mm., upon which scales are mounted. A. Ruled to o.i and o.oi mm. B. Ruled to o.oi and o.ooi inches In order that the microscopist with only a regular microscope model may work with polarized light, we offer these polarizers and analyzers. We list them separately so that any outfit may be made up ; both are necessary in combination to produce the desired results. £0 11 £0 7 Polarizers. These are designed for use in the substage ring and are so mounted as to be interchangeable with an Abbe condenser. The best type of Nicol prism is used in fixed mounting. We supply two styles. Style C has one removable selenite ; style D has three, interchangeable and mounted in metal rings, engraved to indicate the colours to be obtained with polarized light. 13461 No. 2035. Style C 1347' No. 2035. Stvle D £250 £2 16 3 Analyzers. We also furnish two styles of analyzers. Both contain prisms of the Thompson type, cemented with linseed oil, which gives the widest field of all forms of polarizing prisms. Style A is attached immediately above the objective. It has a prism so mounted as to be revolved, placing the prism at any angle with reference to the polarizer. A society screw thread attaches the mounting to the body tube of the microscope while the objective screws into another society thread at the lower end of the mounting. Style B is used above the eyepiece. The Thompson prism is placed in a mounting to which is attached a collar graduated in two-degree divisions, with every tenth line numbered. The prism also is adjustable vertically with a suitable range, to get the proper field of view. It allows the full field of the eyepieces to be utilized up to, and including, the 7.5 x , but cannot be expected to do so with the 10 x and 12.5 x because of the very wide field ot those eyepieces. The cylindrical base of the analyzer fits over the draw-tube and is securely attached by means of a set-screw, which permits a fixed zero point to be established. The prism mounting, including the graduated collar, is removed from the base to permit the insertion of the eyepiece of the microscope ; it is then replaced in the smoothly fitting outer collar. 1348'' Style A 1349' Style B £1 17 6 £2 16 3 CROSS STREET • HATTON GARDEN, E-C 268 BAIRD &IATLOCK (LONDON) LTD. 1350 1351-1355 1350' Filar Micrometer (Bausch & Lomb's) . . . . . . . . . . ..£4100 This micrometer, which is intended for the most accurate measurements, is constructed after the same general plan that we use in the micrometers for our surveying and astronomical instruments. A micrometer screw acts on a slide that carries the movable wire. One revolution of this screw moves the wire 0.5 mm. across the field. This screw has a drum head divided into 50 parts, one part, therefore, being equal to o.oi mm. One tenth of this interval (equal to o.ooi mm. — i p) can easily be estimated. A fine line running through the centre of the field, parallel to the axis of the screw, serves as a guide in orienting the object with reference to the direction of motion of the movable wire. A glass scale placed in the field and ruled in intervals of 0.5 mm. each serves for counting the full revolutions of this screw. Every second interval of the scale is numbered. The eyepiece, which can be focussed on the move- able wire and scale, is of the Ramsden type and has an equivalent focus of 20 mm. (12.5 x ). The Filar Micrometer may be attached to any microscope. It fits into the draw tube and is secured by a set- screw, shown at the left in the illustration. When ordering, the exact inside diameter of the draw tube should always be given. The instrument is finished in black in all exposed parts, except the screw heads, and is supplied in a velvet-lined morocco case. Bausch & Lomb's Drawing Apparatus. This will be found a very useful accessory in all departments of biological work. It is designed for drawing from microscopic specimens where magnified images of from 50 to 430 diameters are desired, the full diameter of the image circle being utilized for all magnifications within that range. It enables one to work with the eye at its normal reading distance from the pencil, a feature greatly appreciated by anyone doing much work of this character. The apparatus is very simply but accurately constructed and is thoroughly satisfactory in use. Adjustments are reduced to a minimum, the standard image distance of 250 mm. (10 in.) from mirror to drawing surface being fixed. While illustrated with a microscope, it is not so furnished unless specified, as it is designed to accommodate almost any standard instrument. SPECIFICATIONS. Microscope Support. Of wood, substantially constructed and neatly finished ; permanently attached to base which is one piece with drawing board ; top surface 128 by 175 mm., height 90 mm. .assuring standard image distance of 250 mm. with microscope in position ; provided with simple metal clamp to hold microscope rigidly in place. Drawing Board. Provides smoothly finished drawing surface 282 mm. (nj in.) square with light shield in position. Light Shield. Sheet metal, neatly finished in black to avoid reflections ; of a size and form to shade effectively three sides of the drawing surface. Mirror. 50 mm. in diameter ; hinged, with stop at angle of 45° to direct image perpendicularly to drawing surface ; mounted on metal clamp which can be readily attached to microscope draw tube in any desired position ; mirror can be raised for changing eyepieces without removing. Lamp. Special hand-feed 90° arc, protected by metal hood having small observation window ; provided with bull's-eye condenser, adjustable in tube for giving parallel or converging beam of light as desired ; entire lamp mounted on support and adjustable vertically and laterally. Rheostat. Of fixed form, accommodating no volts, 5 amperes of current ; must be used with arc lamp to regulate the current 135 11 Complete Drawing Apparatus, as described, without microscope .. .. .. £550 1352T Drawing Board, with microscope support and clamp, and light shield .. .. £0 14 6 1353T Mirror, complete with clamp .. .. .. .. .. .. .. £0 10 6 1354T Special Hand-Feed 90° Arc Lamp, with bull's-eye condenser, as described (requires rheostat also) . . . . . . . . . . . . . . . . ..£300 1355' Rheostat, fixed form, no volts, 5 amperes . . . . . . . . £1 0 10 Note. — Please specify voltage of wiring when ordering. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. Watson's Microscopes. Models made exclusively for Baird & Tatlock (London) Ltd 1356 (with accessories). The aim in the construction of these Microscopes has been to combine the qualities and conveniences of the English and Continental types, and a reference to the illustrations will show the manner in which this has been done. The Tripod Foot is the well-known English pattern, imparting a steadiness to the whole structure, which is obtained by no other design. No matter to what angle the instrument may be inclined it is always firm. The Coarse Adjustment, which is by diagonal rack and pinion, gives a very long working distance between the nosepiece and the stage, enabling low magnifications to be used for lar^e sections, Entomology, etc. The Fine Adjustment is effected by a vertical lever, which is entirely free from complicated mechanism. By this means an exceedingly slow and sensitive movement is obtained, one rotation of the milled head moving the body .1 mm., but movements so minute as TJrr of a turn can be produced, representing .001 of a millimetre, readings for which are obtained on the divided drum attached to the milled head. (Continued on page 271, with prices). CROSS STREET • HATTON GARDE1ST, E- C- f 270 BAIRD &TATLOCK (LONDON) LTD. The Limb is shaped so as to form a convenient handle for carrying and no working part is touched when so used. I A clamping handle is provided to the axis joint. I lii-, instrument is figured under No. 1356, and has a stage with an ebonite surface 4 in. by 4 in. A mechanical | stage can be attached and any other necessary fittings added at a subsequent date to purchase. (For illustration see page 270). Watson's Microscope, B. & T. Model. Stage covered ebonite with clear working surface, 4 in. by 4 in. ; with plain underfilling tube to carry condenser, arranged to lift aside out of the optical axis. 1356r Microscope, Stand only, in mahogany case £7 10 0 Complete Sets, consisting of above microscope, mahogany case with lock and key, and the following accessories : — 1358' Microscope, with two objectives, J in. and choice of i in., § in., or £ In. ; i ocular, No. i, 2, 3 or 4 £9 15 0 i!359T Microscope, with two objectives, Jin. and choice of i in., § in. or i in. ; 2 oculars ; double nosepiece . . . . . . . . . . . . . . • • £10 7 6 1360' Microscope, with two objectives, J in., and choice of i in., f in., or \ in. ; 2 oculars ; double nosepiece ; improved Abbe illuminator with iris diaphragm .. .. .. £11126 1361' Microscope, with two objectives, \ in., and choice of i in., § in. or i in. ; 3 oculars; double nosepiece ; improved Abbe illuminator with iris diaphragm with spiral focussing underfilling .... .. £12 10 0 1362' Watson's Microscope, B. & T. Model, for Bacteriology, with three objectives, \ in. and choice of i in., f in. or i in., and T^ in. oil-immersion 1.30 N.A. ; 3 oculars ; triple nosepiece ; improved Abbe illuminator with iris diaphragm . . £17 5 0 1363' Microscope, with three objectives, \ in. and choice of i in., § in. or i in., and -^ in. oil- immersion 1.30 N.A. ; 3 oculars ; triple nosepiece ; improved Abbe illuminator with iris diaphragm with spiral focussing underfitting 1364' Attachable Mechanical Stage with divisions to movements, for above 1365' Compound Substage, with screws to centre and rackwork to focus, for above . . £17 17 6 extra £376 £1 17 6 B. & T. MICROSCOPE. 1366. This is figured and described under No. 1366 on page 272, and is precisely similar to No. 1356, but has the addition of a mechanical stage and a compound substage. The mechanical stage is constructed as a part of the whole instrument and gives a range of movement of 2 in. horizontally, and I in. vertically. The Compound Substage which carries the Condenser has rackwork to focus and screws to centre. The Body Tube is of large diameter (ij in.) rendering the instrument suitable for Photo Micrography. In the ordinary way Student's eyepieces would be used, but if it were desired to employ large sized eyepieces, the diameter of the body allows of sufficiently large draw-tube to be supplied to accommodate them. The Fittings are all of the Royal Microscopical Society's standard size. The Microscopes are substantially constructed for continuous work, and will maintain their permanent working efficiently, notwithstanding continuous usage. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMlCALS-jf BAIRD & TATLOCK (LONDON) LTD. ' .u „, 1366 (with accessories). Watson s M1Croscope, B. & T. Model (as described page 271) T°der i S tO Centre ™* ™*™* *> «— It can be turned 1366' Microscope, Stand only, in mahogany case mahogany case with lock and key, 1368' Microscope ^with tVoTbjIctrves, J in. and choice of i in., | in. or | fa, ; i eyepiece, 1369" Microscope with .two objectwes.^ in. and choice of i in., f in. «; i in. ; 2'eyepiece; ; double 1370- Microscope with two objectives, j'in. and'choice of 'i in., f'in. or I in • 2' even Fo^BacterioTdgy = impr°Ved Abb<§ illuminat^ with iris diaphragm for substage .' 1371' Microscope with three objectives, J in. and choice of i in., | in. or | in., and oil-immersio, fofsubstage2 OCUlarS'.tnple n°seplece ; imProved Ab^ illuminator with iris-dSphr"gm £12 7 6 £15 2 6 £15 15 0 £17 15 9 £23 2 6 Selection of Microscopes and Accessories. Manufactured by Messrs. SWIFT & SON, London. (Any other Microscope or Fittings of Messrs. SWIFT & SON'S make obtained to order at their list price). 1373 Swift's Petrological Microscope. This instrument has lately been constructed to meet the requirements both of the advanced student and the professional mineralogist. The coarse adjustment is by diagonal rack and pinion. The fine adjustment is by a micrometer screw reading to .01 millimetre. The rotating stage is divided on the edge and reads to 5' . The analyser is of the " Dick " pattern. It is fitted over the ocular, and can (together with its divided circle) be swung aside, out of the optic axis. The prism is of the latest ' ' Glan-Thompson " type, and embraces a very wide & riffle The ocular is slotted to take the micrometer, wedges, etc. It has an adjustable eye-lens to allow of the accurate focussing of its cross webs. A Bertrand lens is fitted in the optical tube. It can be focussed and thrown in or out of the optic axis at will. A centring nosepiece of specially rigid design is provided. Immediately above this is a slot, with a dust excluding cover, cut at 45° to the cross webs, for the reception of wedges, plates, and other compensators. A convergent system of lenses with an iris diaphragm is mounted on a lateral screw focussing adjustment immediately below the stage. When screwed right down the whole of this apparatus automatically swings aside, out of the optic axis. The top lens of the convergent system can be removed when light of very low convergence is required. The polariser is mounted on an independent swing-out arm. The prism is particularly la^e, and will than fill the field. Its mount is divided on the flange, and clicks when the prisms are crossed. 1373' Microscope, as described, with cross-webbed, slotted ocular, in mahogany cabinet A. Extra Bertrand lens, at lower end of body B. Millimetre scale on coarse adjustment, for refractive index work, etc. Millimetre scale on focussing Bertrand lens C. D. Double nosepiece £16 0 0 £0 10 0 £0 10 0 £050 £0 15 0 See page 274 for other accessories. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICAL 273 See page 273 (or Microscope. The following objectives are specially suited for mineralogy : — Nominal Focus. E. .. .. .. .. I in. F. .. J „ G .. | .. H. TV „ Miner alogical Accessories for Microscope No. 1373. I. Ocular fitted with Bertrand's quartered quartz, for extremely accurate reading J. Quartz wedge K. Gypsum plate L. Mica undulation plate (J wave) in vulcanite M. Klein's quartz plate N.A 0.25 £1 13 0 0.88 £3 0 0 0.1)2 £2 10 0 1.30 £5 0 0 •ate reading . . £2 10 0 . . • • £0 18 0 . . • • £0 10 0 . . • • £0 5 0 £0 10 0 SWIFT'S NEW METALLURGICAL MICROSCOPE Designed from suggestions given by Prof. HERBERT JACKSON, King's College, London, and BERTRAM BLOUNT, Esq., F.I.C. 1374 13741 Microscope, Swift's Metallurgical, with one ocular, without objectives, in mahogany cabinet .. .. .. .. .. .. .. £13 !0 o For objectives see Nos. 1399 and 1400. A. Collar Adjustment to high-power objectives For description see page 275. extra £100 BAIRD &.TATLOCK (LONDON) LTD. Description of Microscope No. 1374. See page 274 /or prices. This microscope is the outcome of a number of experiments undertaken to produce an instrument for metallo- ihic work at once simple and efficient. Messrs. Swift & Son believe the design to be the most convenient yet otiered to Metallurgists, Engineers, and others whose work necessitates the examination of the microscopical structure of metals and alloys. The base of the microscope is a strong and heavy horseshoe tripod on which the instrument is exceptionally well balanced. The optical tube is carried by a strong crane arm which gives great firmness and steadiness to the whole body under the highest magnifications. The shape of the arm also makes the microscope one which is very easily handled. The body is moved in a solid fitting similar to that adopted by Continental makers, with the spiral rack and pinion originally patented by the firm of James Swift & Son. The rectangular stage is large and very strong and steady. It is fitted with quick and slow focussing move- ments. The quick adjustment is by spiral rack and pinion worked by the milled head (F) shown in the figure. The slow movement to the stage is obtained by the firm's modification of their well-known lever fine adjustment. The milled head (E) for putting this in action is on the same shaft as that of the rack motion. By this arrangement the greatest convenience is secured as there is no need to shift the hand from one part of the instrument to another in changing from rapid to slow focussing. The application of a strong, steady, and yet delicate fine adjustment of the stage, instead of to the optical tube, is practically a necessity in an instrument designed for the examination of opaque substances under vertical illumination. The stage, as shown in the figure, is solid, but it can be made with an opening, and supplied with a chuck fixed to its under surface so that pieces of rod, etc., may be rapidly adjusted for examination. The illuminator is entirely novel In Its construction. It possesses several new features^which distinguish it from any form of vertical illuminator which has yet been fitted to microscopes for metallographic work. The arrange- ment of its constituent parts will be understood by reference to the figure. It is detachable as a whole from the body tube at (A), so that small photographic lenses may be used when it is desired to obtain a general picture of a large lield. (B) is a milled head for adjusting the angle of the reflector, which consists of a rectangular plate of glass with surfaces worked optically flat and parallel. All chance of any distortion of the image by the reflector is thus prevented. The smaller milled head (c) is the end of a short fitting which passes through (B) and carries small circular stops of various sizes. These are designed to cut out reflections from the lenses of the object glasses. When dealing with bright polished metallic surfaces they are seldom necessary, as the light reflected from such objects sufficiently overcomes that thrown back from the glass surfaces of the lenses. In the case of dull etched surfaces, however, the stops will be found very useful to prevent a general haziness over the image, and to ensure an illumination which will give photographs with clear contrasts. (D) is a handle for moving an Iris diaphragm which works above the reflector, and which will often be found necessary for reducing the aperture of an objective, for cutting off any stray reflections, or for increasing the apparent depth of focus when photographing somewhat uneven surfaces. The whole illuminator can be rotated, round the vertical axis of the microscope, so that the source of light can be placed at the side of the instrument, in front of it, or at any point between these positions. The opening for admit- ting light to the reflector is of sufficient size to clear the aperture of the largest back lens of any objective made. No diaphragm or stop is fitted to this opening, as all modifications in the size or shape of the beam of light thrown on to the reflector should be made by a diaphragm placed close to the radiant source itself, which, when properly adjusted, should be in the same optical focus as the object to be examined. This is effected by making the distance from the radiant to the reflector equal to that from the reflector to eye-lens of the ocular, or to the diaphragm of the ocular if it is of the positive form. It will be seen from this description that the vertical illuminator contains all that is required to secure perfect illumination, and absence of all false light, together with the greatest freedom of adjustment and manipulation, and that the various parts are arranged in a compact form of great strength and steadiness. Messrs. Swift & Son believe that this new illuminator will give the best results obtainable in the examination and photography of metallic and other surfaces where vertical illumination has to be employed. It should be used with objectives properly corrected for uncovered objects, as supplied by Messrs. J. Swift & Son for use with this instrument. If desired, however, a screw adjustment could be fitted to any of their high-power objectives for use with covered or uncovered objects. JAMES SWIFT & SON'S "Universal," " I.M.S.," "Research," and "Army" Microscopes. These four instruments, which have only recently been introduced, form the finest and most comprehensive series of Microscopes yet constructed. Usually they are mounted on massive claw tripods, as illustrated, but a horse-shoe foot can be substituted at the same cost. They incline to the horizontal, in which position they are accurately stopped. The limbs, which are shaped to form a handle for carrying, are milled out of extremely hard phosphor bronze castings, and all bearings are ground and fitted solid. Coarse Adjustment by diagonal rack and pinion on a solid milled and ground in slide. Fine Adjustment by Swift's " Improved Climax " vertical lever, which was introduced and patented by them over thirty-five years ago, and which has recently been widely copied. With this adjustment loss of time or back- lash on reversing the action is absolutely impossible, moreover, there is practically no chance of either the cover glass or objective being injured through careless focussing. The adjustment is operated by two milled heads, one on each side of the limb ; one of these carries a divided drum, one division of which corresponds to a movement of the tube of .001 mm. As the entire adjustment is contained in a cavity milled out of the limb, there is no liability to injury through dust or reagents reaching the working parts. The Draw Tube, which is nickelled, is divided and figured in millimetres. The Substage, which carries the regular Abbe condenser with iris diaphragm and stop carrier, is focussed by a rack and pinion. The optical part can be swung right out of the optic axis. As it is held central by a spring catch, it can instantly be brought back to that position with absolute truth. As they are unnecessary with an ordinary Abbe condenser, centring screws are not provided, but they will be fitted without any extra charge should they be desired. See pages 276 and 277 for prices ot above Microscopes. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 275 BAIRD &.TATLOCK. (LONDON) LTD. cr 1375 1378 Swift's " Universal " Microscope. The coarse and fine adjustments and general construction of this instrument are as described on page 275. It is fitted with the most complete mechanical stage yet designed. The cross motion is effected by a steel worm of new and original design, and the vertical motion by a fine rack and pinion. As the clips which grip the slide are movable against a scale and vernier, it is possible systematically to search over the entire surface of a 3 in. by t in. slide. The entire stage rotates through an angle of about 270° and has centring screws by which its centre of rotation can be set absolutely true to any objective. Both the vertical rackwork movement and the rotation are provided with effective clamps to prevent creeping due to vibration. The horizontal mechanical movement is removable to allow of the use of a Petri dish. For rough work the entire mechanical stage can be taken off the instrument, and be replaced by a plain vulcanite covered stage 1375' Stand as described, in mahogany cabinet, with the following accessories : — Objectives f in. N.A. 0.30 ; | in. N.A. 0.85, and T^ in. oil-immersion, N.A. 1.30 . . Oculars II. and IV. Abbe Condenser with iris diaphragm and stop carrier, dustproof triple nosepiece 1376' The same set as above, but without T\- in. oil-immersion objective Although the sets are quoted with g in. and ^ in. objectives, the jj in. may be replaced by a i in. or J in., and the i in. by a J in. or I in. ; also any of the Huyghenian oculars I.-V. may be taken in place of those named. 13771 Plain vulcanite covered rotating stage, to interchange with mechanical stage . . extra Swift's " I.M.S." Microscope. This Stand, which was specially constructed for use in the Indian Medical Service, was built to meet the requirements of Col. Sir W. B. Leishman. It is intended for bacteriology, haematology, and the most advanced medical research work.. The coarse and fine adjustments and general construction of this instrument are as described above. The mechanical stage is the great feature, as with it it is possible systematically to search over and examine the entire surface of a 3 in. by i in. slide. The cross motion is effected by a steel worm of new and original design, and the vertical motion by a fine rack and pinion. There are three scales and verniers reading to -fa mm- The entire cross movement can be instantly removed when the stage will accommodate a full-size Petri dish. 13781 Stand as described, in mahogany cabinet, with the following accessories : — Objectives § in. N.A. 0.30 ; £ in. N.A. 0.85 ; TV in. oil-immersion N.A. 1.30 Oculars II. and IV. Abbe Condenser with iris diaphragm and stop carrier, dustproof triple nosepiece . . 1379T The same set as above, but without ^ in. oil-immersion objective Although the sets are quoted with § in. and J in. objectives, the f in. may be replaced by a i in. or J in., and the J in. by a J in. or J in. ; also any of the Huyghenian oculars I.-V. may be taken in place of those named. £26 0 0 £21 0 0 £150 £23 0 0 £18 0 CROSS STREET • HATTON GARDEN, E-C 276 BAIRD &TATLOCK (LONDON) LTD. 1380 Swift's " Research " 1382 Microscope. This instrument was designed to meet the special requirements of advanced workers in all branches of scientific research, particularly bacteriology and analysis. The coarse and fine adjustments and general construction of this instrument are as described above. The mechanical stage, which is built in as an integral part of the stand, is of particularly strong and massive construction. The large top plate itself moves in both directions, and its surface can be instantly entirely cleared to accommodate a Petri or other dish. Scales reading by verniers to ^ mm. are fitted to both horizontal and vertical movements. The top plate of the stage is so designed that it can never run foul of the condenser. 1380 Stand as described, in mahogany cabinet, with the following accessories :— Objectives | in. N.A. 0.30 ; J in. N.A. 0.85 ; T\ in. oil-immersion N.A. 1.30 Oculars II. and IV. Abbe Condenser with iris diaphragm and stop carrier, dustproof triple nosepiece 1381' The same set as above, but without ^ in. oil-immersion objective Although the sets are quoted with § in. and J in. objectives, the f in. may be replaced by a i in., or J in., and the J in. by a J in. or J in. ; also any of the Huyghenian oculars I.-V. may be taken in place of those named. Swift's " Army " Microscope. The original instrument, of which this is a modern and improved form, was designed to meet the requirements of Sir A. E. Wright, late of Netley Hospital. The War Office authorities have selected it as one of the standard microscopes for the Army Medical Department. The coarse and fine adjustments and general construction of this stand are as described above. It has a very large plain stage, which will easily accommodate a full-sized Petri dish. The stage is engraved with a Wright's Finder for instantly re-locating any particular part of a specimen. 1382' Stand as described, in mahogany cabinet, with the following accessories :— Objectives f in. N.A. 0.30 ; J in. N.A. 0.85 ; ^ in. oil-immersion N.A. 1.30 Oculars II. and IV. . . . . Abbe Condenser with iris diaphragm and stop carrier, dustproof triple nosepiece 1383' The same set as above, but without TV in. oil-immersion objective Although the sets are quoted with § in. and J in. objectives, the § in. may be replaced by a i in. or J in., and the \ in. by a j in. or £ in. ; also any of the Huyghenian oculars I.-V. may be taken in place of those named £21 0 0 £16 0 0 1384" Attachable Mechanical Stage, horizontal range 3 in. 1385' 2 in. For " Army " Microscope extra £18 0 0 £13 0 0 £350 £2 10 0 277 BAIRD &T*TLOCK. (LONDON) LTD. 1386-1387 Swift's Continental Pattern Microscope which wert S^^^^ and is mounted on a taller pillar than us/al The horse the stand steadier and more rigid than others of this ' t, but with the following improvements, ^ , , Stag6 B °f 6Xtra large size' Partlcularly Iar8e sPread- which renders ' optical tube is replaced bv °ne 3« ii adjustment by diagonal rack and pinion Fine adjustment by isolated direct-acting micrometer screw The draw-tube is nickelled and divided into millimetre 1386' ,387- Stand with ,' in.. J in N.A. 0.85, oil-immersion A in., N.A. 1.30, two oculars, Abbe con- and ttipie £15 £10 0 0 1388' Mechanical Stage Swift's Dele pine Microscope ^^^r^^^L^^^^^^^^ »™* pr- ^epine, Professor of ior those who wish to do post-graduate work istrument for the student in Bacteriology, and Coarse adjustment by diagonal rack and pinion Fine adjustment by isolated direct-acting micrometer screw of a spiting ': Hh VUlCanUe' and is enSraved with ^right's finder for re-.ocating any particu.ar part P^SSSWjiSS^J&J^^ d— ^ *™t Point, may, to- £2 10 0 1389' Stand with in. in., N.A. 0.85, and oil-immersion ^ in., N A denser with iris diaphra gany cabinet 1390' As above, but without ^ in. oil-immersion . objectives or 1391' Mechanical Stage £15 £10 0 0 0 0 ' a i in. extra £2 10 BAIRD &.TATLOCK (LONDON) LTD. 1392 1393 1392' Swift's Diagnostic Outfit, designed by Col. Butler, Army Veterinary Department, War Office This chest was originally designed for use in the Army veterinary service, the idea being to provide the observer with all those materials which he would ordinarily require for microscopical diagnosis in a compact and portable case The contents can be altered, the idea modified to suit any special requirements, and the details of the case and mode of packing are specially carried out with a view to use in all climates.* The contents as at present arranged are :— Delepine, microscope fitted with Abbe condenser with iris diaphragm, triple nosepiece, spiral focussing adjustment, two oculars and §, J, and ^ in. objectives. •The microscope and reagents are so packed that they cannot become displaced during transit. 3 Metal Handle Scalpels. 2 Pairs of Forceps, curved and straight. 2 Needle Holders. 1 Blowpipe. 2 Pipettes. 1 Pair of Scissors. 2 Platinum Needles, i Spirit Lamp. i Nest of Porcelain Dishes. 2 Tubes Methyl Blue. 2 , Eosin. 6 Watch Glasses. I sec. Measure. J Gross Slides. J oz. Cover Glasses, No. i. I Pair of Cornet Forceps. J oz. Cedar Oil. | oz. Balsam in Chloroform. J oz. Anilin Oil. | oz. Potass. Hydr. | oz. Picric Acid. The above outfit has been highly commended by both medical men and veterinary surgeons who have worked in extreme climates. Fuchsin. Gentian Violet. Romanowsky. Leishmann. 4 4-oz. Stoppered Bottles i Leather. i Selvyt. 1393' Swift's Workshop Microscope. Designed by J. E. Stead, Esq., F.R.S. As supplied to the Royal Arsenal, Woolwich, and to most of the great Iron, Steel, and Shipbuilding firms at home, on the Continent, and in America. Price complete, with objective, ocular, * reflector, lamp, and battery This instrument has been designed {or the convenience of engineers, iron and steel founders, and other workers in metals who occasionally require, in their workshops, the use of a compound microscope of x simple form. As the metal objects examined are opaque, the necessity of any substage apparatv The Stand as may be seen from the illustration, is mounted on a tripod base. The legs of this tripod may be lengthened or shortened by rotating the milled heads on them, in order to compensate for any uneven the surface of the object under examination. The lower ends of the legs are fitted with hard steel poi The Optical Tube slides in a cloth lined fitting through the centre of the plate of the tripod, for focussins when the focus has been found the tube may be fixed by a small clamp-screw. The Silvered Reflector is placed in an angular slit in the objective, to which a small electric lamp i attached that when the current from a portable dry battery is turned on, the object is perfectly illumm I The battery is contained in a small wooden case fitted with a switch £21 0 0 £400 279 X BAIRD &. TATLOCK (LONDON) LTD. 1394 Packed in Box. 1394 Ready for Use. Swift's Improved Portable Clinical and Field Microscope ^IS^SsS^SSSSs^!>fsst^ssfsffa the Stand only, in leather case, o by ?i bv ? i' with lla, s»£ '» ^^^^•r'-saa 3 B. Focussmg adjustment for condenser by quick-acting 'screw C. Adjusting screws for centring the condenser E. Abbe condenser, with iris diaphragm VJT» H. Live box (Rousselet's) I. Small live box Other accessories page 281. £500 £2 10 0 £0 17 6 £0 10 0 £1 10 0 £1 10 0 £0 10 0 £0 10 0 £050 280 BAIR.D &TATLOCK (LONDON) LTD. J. Stage forceps K. Pliers L. Eyepieces, i to 5 M Double nosepiece N. Stops for dark ground illumination and oblique light with blue glass modifier See No. 1400 for Objectives. each £0 4 £0 1 £0 6 £0 10 £0 7 6 0 0 0 0 1395-1396 Swift's Discovery Microscope. This is the ideal instrument for the student. It is very strongly built, and the tripod upon which it is mounted renders it extremely steady. Coarse adjustment by diagonal rack and pinion. Fine adjustment by isolated direct-acting micrometer screw. The stage will carry a full-size culture dish. It is engraved with Wright's finder, for re-locating any particular part of a specimen. The understage fitting is of standard size. It can be replaced by a racking and centring substage at any time The draw-tube is nickelled and divided into millimetres. Plane and concave mirrors are fitted. 1395' Stand with f in. and J in., N.A. 0.85 objectives, ocular and iris diaphragm, in mahogany cabinet 1396' Stand with § in. and J in., N.A. 0.85 objectives, two oculars, double nosepiece and iris diaphragm, in mahogany cabinet Although the sets are quoted with j in. and ^ in. objectives, the f in. may be replaced by a i in. or 4 in. and the i in. by a J in. or J in. objective. Accessories for above Microscope — A. Mechanical stage B. Racking and centring substage C. Small Abbe condenser extra £6 15 £7 10 £2 10 £1 15 £0 10 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 281 BAIED &TATLOCK (LONDON) LTD 1 1398A 1398B 1397 13971 1398c microscope, sloping from the stage to ) suit the convenience of the operator. Price A. Iris diaphragm . . B. Cabinet for microscope extra £10 0 0 £100 £0 10 0 £150 13981 A. Double Nosepiece for two objectives B. Triple „ three C. Quadruple „ four £0 15 0 £100 £2 10 0 BAIRD &TATLOCK (LONDON) LTD. 1399' James Swift & Son's New Apochromatic Objectives. Equivalent Focal Length Initial Magnifi- cation. Numeri- cal Aperture. Magnifications with Compensating Oculars. Tube Length — 160 mm. Image Distance — 250 mm. l>rice. Ins. | mm. X2 X4 x6 X8 XI2 Xi8 X24 X28 Aii Bi C j D i E J i- ! T'*| 2 121 i-35 242 484 726 968 1452 2178 2904 3388 £8 10 0 L Al 2 121 1.40 242 484 726 968 1452 2178 2904 3388 £10 10 0 1400' James Swift & Son's Improved Achromatic Objectives. Equivalent Focal Length. Numerical Aperture. Initial Magnifi- cation. Magnifications with Huyghenian Oculars on 160 mm. Tube. Price. I. II. in. IV. V. A 5 in. O.O6 2 6 8 ii 14 18 £150 B 4 „ 0.09 2-5 7-5 10 13-5 17-5 22.5 £150 C 3 ,, 0.09 3-5 10.5 14 19-5 24-5 31-5 £110 D 3 ,. 0.12 3-5 10.5 14 19-5 240 31-5 £1 13 0 E 2 „ 0.14 5 15 20 27-5 35 45 £1 1 0 F 2 ,, 0.17 5 15 20 27-5 35 45 £1 13 0 G ii ,, 0.16 7 21 28 38.5 49 63 £1 1 0 H ii „ 0.20 7 21 28 38.5 49 63 £1 13 0 I i" „ O.2O 10 30 40 55 70 90 £1 1 0 J i -, 0.25 10 3» 40 55 70 90 £1 13 0 K i „ 0.30 IO-5 31-5 42 57-5 73-5 94-5 £250 L 2, ,, 0.30 17 42 58 74 9i 153 £1 1 0 M i „ °-35 20 60 80 no 140 180 £1 10 0 N 1 „ 0.50 20 63 84 H5 147 189 £200 O * 0.50 3« 9° 120 165 2IO 270 £1 10 0 3 ** P 1 0-75 42 126 168 231 294 378 £1 10 0 4 ' ' Q 1 „ 0.85 43 129 172 236 301 387 £200 R t „ 0-95 43 129 172 236 301 387 £300 s -i „ 0.65 60 1 80 240 330 42O 54» £1 10 0 T i , 0.85 60 180 240 330 420 54« £1 10 0 D 1* u j „ 0.95 61 183 244 336 427 549 £300 v i „ 0.85 81 243 324 445 567 729 £1 10 0 w i „ 0.92 82 246 328 45i 574 738 £2 10 0 x i „ °-95 82 246 328 451 574 738 £400 OIL IMMERSION SYSTEMS. Y i 1.30 83 249 332 456 581 747 £400 2 _i 1.30 1 02 306 408 561 714 918 £400 \A ^ 1.30 125 375 500 687 875 1125 £500 BBTV,, 1.30 1.30 165 204 495 612 660 816 907 1122 "55 1428 1485 1836 £7 10 0 £10 0 0 DD Adjustable Cell to any system above \ in. extra £100 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 283 BAIRD &. TATLOCK (LONDON) LTD. 1401' Swift's Compensating Oculars. For Continental Tube, 160 mm. Magnification Price Magnification Price 1403T Swift's Huyghenian Oculars. Designation Magnification Price . . X2 20/- X4 20/- X6 20/- X8 30/- XI2 30/- Xi8 251- s. For Long English Tube, 10 in. X4 251- X6 25/- X8 35/- XI2 30/- Xi8 30/- X24 30/- X28 25/- • • I. II. III. IV. V. X3 61- X4 6/- X5-5 61- xy 6/- X9 61- 1404 1404T Swift's New Dark Ground Condenser. This dark ground Condenser was designed, and is primarily intended for, the examination, under high powers, of living unstained bacteria. As it brings the rays to a focus by reflection only, and not by refraction, it is absolutely free from chromatic aberration and, owing to the design and disposition of the two reflecting surfaces, the various forms of spherical aberration are reduced to a minimum. They are present in a far less degree than in the most carefully ground paraboloid, which surface it is mechanically impossible to polish absolutely true to figure. The condenser is computed to work through slips varying from i mm. to 1.25 mm. in thickness, and to give satisfactory results with a comparatively weak source of light. A descriptive leaflet will be sent on application. Full instruc- tions accompany each condenser Dark Ground Condenser, with R.M.S. standard screw Centring Adjustment for same Stop for reducing aperture of immersion objectives . . . . £0 1 6 to The internal diameter of the Substage should be given when a Centring Adjustment is ordered. CAMERA LUCID,*. 1405T Swift-Ives Camera Lucida. This is a modification of the well-known Abbe pattern in which the large mirror is replaced by a small total reflecting prism. It can be used with the Microscope either vertical or inclined 1406T Wollaston's Camera Lucida with two adjustable lenses for rendering the object and pencil equally visible 14071 Wollaston's Camera Lucida as above, without lenses POLARISING APPARATUS. 1408T Polariser to fit Substage and Rotating Analyser 1409T Ditto ditto Fixed ditto.. 1410T Smaller ditto ditto 141 1T Analyser fitted to slide in and out of body of Microscope £1 10 £0 10 £0 2 £1 5 £1 5 £0 17 £200 £1 10 0 £150 £1 10 0 When a Polariser is ordered the inside diameter of the substage of the Microscope should be given. 14 -CROSS STREET • HATTON GARDEN, E- C BAIRD &TATLOCKL (LONDON) LTD. Microscope Cover Glasses, Slides, FULL SIZES. 1420 1421 in. in. I in. i in. i] in. 1421 i J by | in. 2 by J in. 1420 Microscope Cover Glasses, circles, finest English glass. No. i. No. i. Selected extra thin for oil-immersion lenses. Ordinary. Thickness about . . . . ^ .^>v Price per oz. . . . . 6/6 4/- Price per oz. for 6 oz. quantities 6/- 3/6 The following sizes stocked in £ oz. boxes : — |, J, £, i, and Any size cut to order. 1421 ' Microscope Cover Glasses, squares, finest English glass. 2 by i{ in. No. 2. 31- 2/9 in. diameter. No. i. Selected extra thin for oil-immersion lenses. Thickness about . . . . -^v Price per oz. . . . . 5/6 Price per oz. for 6 oz. quantities 5/- The following sizes stocked in No. I. Ordinary. i 3/6 No. 2. 2/9 oz. boxes : — |, |, |, i, ij in. square, and i J by J, 2 by J, 2 by Any size cut to order. No. 3 2/6 2/3 No. 3. rihs '' 2/6 2/3 in. .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 285 BAIRD &TATLOCK (LONDON) LTD. 1422 1422s Microscope Cover Glasses, circular, with square in centre divided into sixteen parts, and each division numbered for use with Bottcher's slides, Fig. 1435 . . . . each £0 1 1423 (full size) 1424 (full size) 1423 (in £ gross box). A1424 (full size). 1423 Microscope Slides, extra clear glass and uniform, edges ground and smoothed, 3 by i in. (No. i quality) i 5 I0 20 gross. 4/6 4/3 4/- 3/10 per gross. 1424 Microscope Slides, clear glass and uniform, edges ground and smoothed, 3 by i| in. (No. i quality) . . ' . . . . per gross £066 A 1424 Microscope Slides, clear glass and uniform, edges ground and smoothed, 3 by 2 in. (No. i quality) . . per gross £070 1425 Microscope Slides, clear glass and uniform, edges ground and smoothed, 3 by i in. (No. 2 i 3/6 5 3/4 10 3/3 20 gross. 3/2 per gross. 1426 Microscope Slides, clear glass and uniform, edges ground and smoothed, 3 by it in. (No. 2 quality) . . .. . . . . 'per gross £056 A 1426 Microscope Slides, clear glass and uniform, edges ground and smoothed, 3 by 2 in. (No. 2 quality) .. .. . . . . . . . . . . per gross £060 CROSS STREET- HATTON GARDEN, E-C 286 BAIRD &TATLOCK (LONDON) LTD. 1427 Microscope Slides, thin greenish glass, 3 by i in. (No. 3 quality) i 5 10 20 2/9 2/8 "2/7 2/6 1428 Microscope Slides, thin greenish glass, 3 by i£ in., (No. 3 quality) M428 ,, „ „ „ „ 3 by 2 in. 1429 Microscope Slides, ground and smoothed edges, 3 by i in. (" special quality "), extra hard clear glass, suitable for use in hot climates. Per gross Ten gross 50 gross lots. 2/4 per gross. per gross £046 £050 £046 per gross £043 1431 A 1430 1435 1436 1437 1430 Microscope Slides, thin greenish glass, selected, 3 by i in., specially suitable for use in tropical climates. i 5 10 20 gross 3/6 3/4 3/3 3/2 per gross. A1430 Bottled in alcohol 4/9 4/7 4/6 4/5 1431s Microscope Slides, Dr. C. L. Birmingham's pattern, 3 by i in., thin greenish glass per gross Extract irom British Medical Journal. — Dr. C. L. Birmingham (Westport, co. Mayo) writes to draw attention to a form of micsoscope slide which he has used for some years, and which he regards as both convenient and time- saving. The device consists in having about half an inch of one extremity of an ordinary slide bent upwards at an angle of 40 degrees. When such a slide is used for smear work it will be found, he says, that (i) the fingers do •not get stained, (2) the slide can be dried by simply inverting it, and (3) there is no doubt as to which side contains the film. He adds that it is specially convenient for taking sputum specimens at the bedside, and that they can easily be fixed at once, preferably by " spiritine." £060 1432s Tins of Spiritine for above each £006 1433 Microscope Slides, extra thin half white glass and uniform, edges ground and smoothed, 3 by i in. (No. 2A quality) i 5 10 20 50 gross lots. 3/- 2/10 2/9 2/8 2/6 per gross. 1434 All Microscope Slides and Cover Glasses used in hot climates should be stored in alcohol. Extra cost of bottle and alcohol (see Fig. Ai43o) for 3 by i in. slides per gross slides £013 1435 Microscope Slides, Bottcher's, with 15 millimetre ring for moist chambers each, 7d. ; per doz. £066 1436 Microscope Slide, with cell 15 millimetres, plate cemented on I to 2 millimetres thick each, 7d. ; per doz. £066 1437 Dr. Eternod's Plate, with circular cavities for a series of sections, each hole 25 millimetres diameter and 7 millimetres deep ; bottom plate cemented on. (See Zeitschrift fur Wissenchaftliche Mikroskopie und fur Mikroskopische Technik, Band VIII., 1892, pp. 13, 14.) 10 holes . . . . . . . . . . . . . . each £0 10 0 .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 287 BAIRD &TATLOCK (LONDON) LTD. 1438 14,59 1440 1438 Microscope Chambers, for the cultivation of hanging drop cultures in different gases each, 1/3 ; per doz. £0 14 Microscope Cover Glasses (see Nos. 1420-1421). 1439 Microscope Slide, 3 by i in., 3 millimetres thick, with hole and rim in order that specimens may be observed from both sides. Price per dozen Price each £0 4 £0 0 1440 Microscope Slides, Ranvier's, 3 by i in., 2 to 3 millimetres thick, upper side ground, with round polished depression of 12 millimetres diameter, surrounded by a i to 2 milli- metres broad groove. (Damp chamber.) Price per dozen Price each 1441 1442 1443 1442 Glass Plates, with polished cavities. Size . . . . . . 120 by 60 Cavities . . . . . . 9 Price each . . . . 3/6 160 by 130 millimetres. 12 m/m diam. 5/6 1443 Cuvettes, oval shape, with loose drop on cover, bottom and top polished, for microscopical purposes, 83 by 45 by 19 millimetres. Price per dozen £036 £004 1444 1441 Compressors for Meat Research, consisting of two thick glass plates, with two screws. Size, 210 by 50 millimetres, divided into 24 spaces numbered . . each £0 2 £066 1444 Cylinders, with small dish inside, with cover polished, 7 by 3J centimetres. Price per dozen Price each £0 9 £0 0 0 10 1445 (side view) 1445 Moist Chamber, by Geissler-Klebs. Price per dozen Price each 1445 (top view) £0 13 0 £0 1 2 CROSS STREET • HATTOTST GARDEN, E-C BAIRD &TATLOCK (LONDON) LTD. -* 1446 (side view) 1446 Moist Chamber, by Geissler-Recklinghausen. Price per dozen Price each 1446 (tup view) 1447 £0 15 0 £0 1 4 1447 Ward's Tubes, ground on both sides, for the examination of organisms on micro slides in a current of gas . . . . . . . . . . each 6d. ; per do?.. £056 1448 1449 1450 1448 Microscope Slide, with ring and two gas-leading tubes, with cover plate, by Fritsch. Price per dozen . . .. £0 18 0 Price each . ., . . £018 1449 Microscope Slide, 3 by i in., with end ground for writing on. Price per dozen £009 Price per gross . . £086 1450 Glass Rings, for micro slides, ground flat both sides. Diameter, external ..... 15 18 20 22 millimetres. Height .. .. --3 5 7 9 Price per dozen .. ..1/4 1/9 2/3 2/6 A 1450 Aluminium Rings, for micro slides, as Fig. 1450 . . f 6/- J in. external (Hum. 6/- per gross. f .„ ' ' '.($ 5 1451A 1451B 1451C 1451 Moist Chambers for observing hanging drops, size 3 by i in., ij millimetre thick, ground edges, with round polished depressions. ABC 123 depressions. Diameter of depressions . . . . 15 15 15 millimetres Price per dozen .. .. .. 9d. 1/2 1/8 Price per gross . . . . . . 8/6 13/- 19/- 1452 1453 1452 (Section) 1452 Moist Chamber, by Eilhard Schulze, consisting of thick glass plate, 50 millimetres square, with 3 millimetres broad groove and perforated cover plate . . each, 1/8 ; perdoz. £0 1453s Indiarubber Mats, for draining cover glasses, after staining, 8 by 5j in. . . each £05 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS.™ ^ A A' 1454 1455 1454 Pith, for mounting microscope and botanical objects, etc. per bundle, 6d. ; perdoz. bundles 1458-1459 1458 Boxes for sending Slides by Post to hold one 3 X i in. slide 1459 ,, „ ,, „ ,, „ to hold two 3 X i in. slides 1460 Boxes for sending Slides by Post, with rack for slides. For 2 4 211- 281- 1460 per gross 6 slides. 35/- per gross. £056 1455T Microscope Warm Stage, heated by water. This stage has the advantage of being very simple in construction, and being specially thin it can be fitted by means of two screws to almost any microscope. A simple condensing lens is included, which enables the highest magnifications to be used with it, even oil-immersion objectives . . . . £2 0 0 1456 A1457 1456 Microscope Slide Heater, with clips for holding slide on the stage of microscope, each £019 1457 Turntable, brass disc with two clips fitted, revolving on mahogany block . . . . £086 A14571 Turntable for ringing cover-glasses, with clips for holding the slide .. .. .. £0 10 0 £0 11 6 £100 290 BAIRD &TATLOCK. (LONDON) LTD. 1461 1462 (Open) 1462 (Closed) 1461 Oak Cabinets, for microscope slides, with 25 trays, for 20 slides, each 3 by i in., in all 500 slides .. .. .. .. .. .. .. . . £1 12 0 1462 Cloth Covered Cardboard Boxes, book form, to hold 3 by i in. microscope slides. Size, ii by 8 in. by ij to 2 in., for 100 slides £040 1463 1464 1465 1465 (Envelope) 1467 1463 Cloth Covered Cardboard Boxes, book form, to hold 3 by i in. microscope slides. Size, 8 by 5 in. by if to 2 in., for 50 slides 1464 Cloth Covered Sliding Boxes, for microscope slides, 3 by i in. A. To hold 12 slides B. 25 £026 each £009 £0 1 1 1465 Microscope Slide Cases, with sliding envelope to hold 12 slides 3 by I in., suitable for pocket .. .. .. .. .. .. each, 1/3 ; per doz. £014 0 1466 Microscope Slide Cases (Fig. 1465), to hold 6 slides 3 by i in., suitable for pocket each, I/-; per doz. £0 11 0 1467 Boxes, to hold slides 3 by i in., grooved, of plain white wood. 1236 dozen. Price each .. 4d. 7d. 9d. 1/2 Price per dozen . . 3/9 6/6 8/6 13/- BAIRD &TATLOCK (LONDON) LTD. 1468 ,,,Q 1469 Trays, for slides, of strong cardboard, with folding flaps, to hold slides 3 by i in Price each No. of Slides 6 14 Price per dozen 1470 Trays, for slides, of strong cardboard, with folding flaps, to hold 10 slides 3 by 2 in. each, 9d. ; per doz. £0 8 6 Trays, for slides, of strong cardboard, with folding flaps, to hold 10 slides 3 by ii in. each, 9d. ; per doz. £086 Trs *» pa* „ „ . 1472 1472 Cabinets, varnished pinewood, for holding slides. 3 by i in. A. To hold i dozen slides each E- 3 4 6 12 £0 1 3 £020 £026 £030 £0 3 6 £066 292 BAIRD &.TATLOCK (LONDON) LTD. 1473-1474 1475-1476 1473 Cabinet, for slides, wood covered with cloth, with cardboard trays, to hold 2 gross 3 by i in. slides .. .. .. .. .. .. .. .. £010 6 1474 Cabinet, same as above, to hold i gross 3 by i in. slides . . . . . . . . £076 1475 Cloth Covered Cardboard Boxes, with 12 cardboard trays, for 108 slides (3X1 in.) each £020 1476 Cloth Covered Cardboard Boxes, with 6 trays, for 54 slides (3x1 in.) .. ,, £016 1477-1478 1479 1477s Cabinets, for microscope slides, polished mahogany, with lock and key, trays numbered i to 500. The bottom of the trays are made of aluminium, and in each division of tray two ridges are formed along the bottom, on which the slides rest. They are thus more readily picked up than when lying flat. To hold 500 slides, 3 by i in. 1478s Cabinets, as above, to hold 1,000 3 by I in. slides . . 1479s Microscope Slide Cabinets, of japanned iron, black outside, white inside, with glass panelled door and slide trays to carry 3 by i in. slides, for hot climates. The trays are made entirely of aluminium, and in each division of tray 2 ridges are formed along bottom of tray on which the slides rest. They are thus more readily picked up than when lying flat. For 200 500 i.ooo slides, 3 by i in. Each £250 £2 18 0 £440 iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 293 BAIRD &.TATLOCK (LONDON) LTD. 1480 (Open) 1480 (Closed) 1481 1480 Microscope Case, wood, weighing only about 6 oz., with indexed cover corresponding to index inside of box, for 50 slides, 3 by i in. . . . . each, 1/6 ; per doz. 1481s Microscope Slide Cabinet, to carry 240 slides 3 by i in. The cabinet consists of cardboard trays fitted m polished pitch pine cabinet with hinged back, folding down front lock and handles £0 17 0 £1 1 0 1482 1483 1482s Microscope Slide Cabinet, superior finish, to carry 500 slides 3 by i in., arranged with 24 trays The trays are made of teak, with aluminium bottom. All trays are The cabinet is strongly made of teak, with hinged back and drop down front, and is fitted with handle and lock . 1483 Paraffin Block Cases, for holding paraffined sections- Size of paraffin block . . . . 2 For . . . . . . . . 98 Price .. .. ..6/6 3 4 cm. squares. 154 98 preparations. 10/- 14,'- each. 3 0 294 BAIRD &TATLOCK (LONDON) LTD. 1484 1484 illustration of Tray. 1484 Microscope Slide Cabinets of oak, with trays having aluminium bottoms and grooved vertically to hold 3 by i in. slides, glazed doors, with lock and key, trays numbered. To hold 1,000 2,500 5,ooo 10,000 slides, 3 by i in. Price each £5150 £880 £12 0 0 £17 10 0 1485 I486 1487 (illustrations full size) 1485 Forceps, Cornet's, with vertical points, for holding cover glasses each, 1/3 ; per dcz. 1486 Forceps, nickel-plated, with smooth tips for cover glasses, etc., specially suitable for plugging test tubes .. .. each, 1 /6 ; per doz. 1487 Forceps, Bulldog pattern. Size Nos. 35 36 37 38 1/6 1/9 2j- 2/6 each £0 14 6 £0 17 0 295 BAIRD oks containing 200 labels. See No. 3438 for detailed list .. per book £0 1 0 (See also Gummed and Varnished Labels in Chemical Section, Nos. 3436-3442). Surgical and Dissecting Sets. 1533 " 1533 (Pouch) sdssors' °ne pair each £086 pked i , °ne Pair f°rcePs' OIle P"be, one pair scissors e ftWrtf one straight needle in case, two cannufce, all in nickel case, with leather pouch for the pocket o , = sfcl O U JOO BAIRD &.TATLOCK (LOM)ON) LTD. 1534 1535 1534s Dissecting Set, containing six scalpels (in ebony handles), blowpipe, chain hooks, spring forceps, scissors, and needles, in mahogany case .. .. .. .. .. £0 17 6 1535s Dissecting Set, containing blowpipe, cartilage knife, catlin, chisel, "saw, all fitting one handle ; spring forceps, three scalpels in ebonised handles, scissors, and needles, in brass- bound mahogany case . . . . . . . . . . . . . . ..£200 1536 1537 1536s Dissecting Set of finest Sheffield manufacture, specially arranged for botanical work, etc. in polished mahogany case. Price per set . . . . • £0 17 6 List of Contents. One pair large scissors. One pair small scissors. One pair large forceps. One scalpel, i| in. blade. One scalpel, 2 in. blade. One scalpel, 2} in. blade. Two needles in handles. Two razors. 1537s Dissecting Set, containing one section razor, two scalpels, one spatula, one pair scissors (bent), one pair scissors (straight) four needles and seeker mounted, suitable for micro- scope work, in leather case £0 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 301 BAIRD &TATLOCK. (LONDON) LTD. 1538 1539 ' 1538s Dissecting Set, containing blowpipe, bowel scissors, cartilage knife, catlin, saw, chisel, forceps, hammer, six scalpels, scissors, spine chisel, chisel, and needles, in mahogany case brass-clipped . . . . . . . . . . . . . . . . ..£476 1539s Dissecting Set, containing bone forceps, brain knife, cartilage knife, chisel, forceps, mallet, needles, saw, wrench, two scissors, six scalpels, in plain mahogany case . . . . £4 4 0 1540 1541 1540s Dissecting Set, containing three scalpels, scissors, saw, cartilage knife, catlin, and chise), all fitting one handle ; forceps, hammer, and blowpipe, in brass-bound mahogany case £330 1541s Dissecting Set, containing skull rest, scissors, two scalpels, saw, catlin, chisel, and cartilage knife, fitting one handle ; forceps, hammer, blowpipe, and needles, in mahogany brass- bound case .... £330 CROSS STREET • HATTOTsT GARDEN, E-C 302 i ST u BAIRD &.TATLOCK (LONDON) LTD. 1542 542» Dissecting Set, containing two scalpels, bowel scissors, scissors, saw, hammer, wrench, forceps, needles, blowpipe, spine chisel, cartilage knife, and catlin, in brass-bound mahogany case . £440 1543 1543s Dissecting Set, containing skull rest, six scalpels, two scissors, forceps, bone forceps, bowel scissors, hammer, saw, chisel, cartilage knife, catlin, brain knife, needles, and wrench, in plain mahogany case . . . . . . . . . . . . £6 6 0 305 BAIRD &TATLOCK (LONDON) LTD. 1544 1544s Dissecting Set, hospital and infirmary pattern, containing bowel scissors, scissors, saw, two forceps, tripod head rest, hammer, boxwood mallet, skull coronet, wrench, chain hooks, six scalpels, brain knife, two cartilage knives, catlin, needles, and blow-pipe, in strong mahogany box with brass clips on corners SINGLE INSTRUMENTS AS FITTED IN CASES, 1532 to 1544. A 1544s Blowpipes, German silver . . . . . . . . . . . . each 1545s Bowel Scissors 1546s Brain Knives .. 1547s Cartilage Knives ., 1548s Chain Hooks .. .... .. .. .. set 1549s Chisels .. .. .. .. .. .. ,. .. each 1550s Forceps 1551s Hammers . . . . . . . . . . . . . . . . „ 1552s Mallets 1553s Saws 1554s Scalpels (see Fig. No. 1523) . . 1/3, 1/6, and 1555s Scissors . . . . . . . . . . each, 5 in., 1/9 ; 5! in., 2/- ; 6 in. 1556s Skull Coronets 1557s Spine Wrenches 1558s Tripod Head Rests each £0 £0 1 ' 7 I £0 5 I 4 : 1 : 2 I 1 I 7 I £0 £0 £0 £0 £0 £0 2 I £0 15 I £0 1 ' £0 2 i £1 5 i £0 5 I £0 16 I 1560 1560s Forceps, with slightly hooked points, specially suitable for large dissections £0 8 14 • CROSS STREET • HATTOTST GARDE1ST, E- C 304 BAIRD &T&TLOCK. (LONDON) LTD. Microtomes and Accessories. 1561a 1562-1563 1562 (Clamp) 1561s Microtome, Cathcart's, with spray bellows, ether points, double clamp, ether bottle, and L shaped moulds for embedding, price complete A. Razor, ground flat on one side (Sheffield make) . . each, 1/6 ; per doz. B. Spray bellows . . . . . . . . . . . . each C. Ether points (extra sets) 15629 L Moulds for embedding with paraffin, brass, large . . 1563s small per pair £1 1 0 £0 17 0 £026 £020 £026 £0 1 6 1564 1565 1564s Cathcart's Microtome, improved pattern, with knife carrier, razor, and register of thick- ness, arranged both for freezing and embedding . . . . . . . . ..£1106 1565s Plane Blades for microtomes, 3 in. broad, with wooden handle . . • • each £046 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 1566 1566T Microtome, Williams', for freezing with ether spray. It can also be used for cutting sections of tissues in paraffin . . . . . . . . . . . , ..£350 1567 15671 Swift's Freezing Microtome. Price complete, to freeze with ice . . This apparatus can be used for embedding with paraffin, celloidin, or other medium. £2 17 6 CROSS STREET • HATTON GARDETST, E- C 306 BAIRD &TATLOCK (LONDON) LTD. 1569 1572 1568 1568r Cambridge Rocking Microtome, igoo pattern, with simple object holder, orientating object holder (Fig. 1572), and knife The advantages of the new microtome are : — • 1. Increased rigidity. 2. Impossibility of tearing sections on the upward movement of the object. 3. Increased uniformity in cutting sections. 4. Graduated arc for showing the thickness of the sections. 5. Catch for holding the object above the razor edge. 6. Improved method of fixing the cord. 7. New object holder. (See Nature, 3Oth November, 1899.) Accessories for the above Microtome. 1569' Object-Holder for Wooden Blocks, including six hard wood blocks of two different sizes 1570' Spare Hard Wood Blocks, 22 mm. square .. .. .. . . per doz. 1571' ,, ,, „ ,, 16 by 22 mm. .. .. .. .. ,, 1572' Orientating Object-Holder — Simple Pattern 1573r „ „ —With Adjustments 1574' Spare Simple Object-Holder .. 1575' Knife, best Sheffield make 1576' Best quality Hone, 7 in. long, in polished mahogany case £4 15 0 £0 £0 1 £0 1 £0 6 £0 16 5 6 0 0 I) 0 £0 1 0 £026 £080 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 307 BAIRD &TXTLOCKL (LONDON) LTD. -•;. General view of Large Sliding Microtome. 1577 Fig. 3. Section through the adult human leg. Full Prepared and cut with the Large Sliding Microtome a Anatomy School, Cambridge University. Sliding Microtome, new pattern, large, capable of cutting sections embedded in celloidin and measuring 150 by 120 mm. (6 in. by 4| in.). General. This Microtome has been designed for cutting flat sections up to 150 x 120 mm. (6 in. x 4| in.). It is capable for cutting through decalcified bone or cartilage, and is being found extremely useful for cutting sections which are too large to be cut with either of our two rocking microtomes. Fig. 3 is an illustration, full size, of a complete section of the human leg six inches above the ankle, prepared and cut with this new micro- tome at the Anatomy School, Cambridge University. Capability of the Instrument. The microtome will cut sections measuring up to 150 x 120 mm. (6 in. x 4$ in.) in either paraffin or celloidin. The thickness of the sections can be varied from o to 0.06 mm., each division on the scale being equal to 0.002 mm. The total distance through which the microtome will automatically feed the object-holder is 21 mm. Advantages. Some of the principal advantages of this microtome are : (1) It is extremely powerful and will cut through decalcified bone and cartilage. (2) It will cut sections from very large objects. (3) It will cut either paraffin or celloidin sections. (4) It is designed on geometric principles so that even after many years' wear it will still cut true sections. Complete Pamphlet with directions for use on application. 1577' 1578T Large Sliding Microtome complete with knives " A " and " B," Nos. 1580 and 1581. The knives are supplied in a suitable case and the necessary stropping attachments and one interchangeable handle are included. Three hard-wood blocks of different sizes suitable for use in the object-holder are also included . . . . . . . . £40 10 0 Large Sliding Microtome with knife "B" only, No. 1581. Case for knife, stropping attachment, handle and three hard-wood blocks included (see note top of page 309) . . £38 1579T Ditto, but with knife " A " instead of " B " . . . . . . £38 8 0 8 0 Accessories for the above Microtome. 1580T Spare Knife, " A," 30 cm. long, in case 1581T Spare Knife, " B," 30 cm. long, in case 1582' Stropping Attachment for Knife No. 1580 1583' Stropping Attachment for Knife No. 1581 1584T Spare Handle. For use with either Knife No. 1580 or 1581 . . 1585T Spare Hardwood Blocks. As used in the object-holder. A. Large size, 150 by 120 mm. . . B Medium size, no by 90 mm. C. Small size, 80 by 60 mm. each £240 £240 £026 £026 £036 £0 1 6 £0 1 3 £0 1 0 CROSS STREET • HATTOTST GARDETST, E- C 308 BAIRD &TXTLOCK (LONDON) LTD, 15861 Large Best Quality Hone. Surface dimensions 320 by 70 mm. .. .. .. £1 12 0 1587' Strop, four-sided, with handle. 23 cm long .. .. .. £056 KB.— All cases are made to hold two knives. When one knife only is ordered, knife " 13 " is the one found most generally useful. 1588 1588T Cambridge Rocking Microtome, for flat section cutting, with double lever as in small pattern, to prevent cutting thin and thick sections, complete with simple object-holder, orientating object holder, simple pattern and knife .. .. .. •• .. £10 8 0 Accessories for above Microtome. 1589' Object Holder for wooden blocks, with six hardwood blocks of two different sizes each £076 1590' Spare Hardwood Blocks, 32 mm. square . . . . per doz. £016 1591' „ „ ,. 25 by 32 mm. .. ,,£016 1592' Orientating Object Holder, simple pattern .. £0 11 0 1593' „ „ „ with adjustments .. £0 18 6 1594' Spare Simple Object Holder .... £010 1595' Knife, best Sheffield make . . . . . . ..£026 1596' Hone, best quality 7 in., in polished mahogany case . . ..£080 ,n CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICAL; 309 BAIRD &TATLOCK. (LONDON) LTD. 1599 1597 1598 1597 Hones for sharpening razors, best quality Length . . 6 8 q Each 2/6 4/- 8/- 12/- 1598 Microtome Razor, with handle, all steel, in wood case, with leather strop 1599 Razor Strops .. 1600 Strop for Razors, Zimmer's equilateral pattern 1600 10 in. 15 - £036 each £0 1 6 £056 1601 1601 Grindstone, for sharpening tools and' grinding sections of hard bone and teeth, with iron hood. A. 6 in. diameter . . . . . . . . . . . . . - • • £070 B. 8 in. ..£086 1602 In tliis microtome there are two slides, one of which, the object-slide, ascends gradually towards the knife- slide. Upon the object-slide there is a clamp fastened to a carrier, and in this clamp the paraffin or celloidin block is fixed ; upon the knife-slide there is a heavy carrier to which is clamped the knife. By means of a micrometer screw the object can be made to gradually ascend the slide, and thus by drawing along the knife, sections are cut. This microtome can be used for tissue embedded either in paraffin or celloidin. 1602' Jung's Slide Microtome, consisting of— Iron stand, 40 centimetres long A. Slide for object with simple clamp . . B. Micrometer screw with divided head for exact cutting to o.ooi mm. C. Thoma's knife, 24 centimetres, in case D. Setting and stropping bevel for knives £7 i i i o o o 6 o 6 £12 13 0 CROSS STREET • HATTCflSr GARDE1ST, E-C BAIRD &TATLOCK (LONDON) LTD. 1603 1604' Jung's Slide Microtome, pattern Fig. 1602, consisting of— Iron stand, 40 centimetres long A. Slide for objects with clamp, rack and pinion and vertical adjustment B. Micrometer screw with automatic ratchet C. Two Jung's knives, 24 centimetres (A) for celloidin cutting, at £ 6 o D. Two Thoma's knives, 17 centimetres (B) for paraffin cutting, at £i E. Case for three knives, 24 centimetres F. Case for three knives, 17 centimetres G. Knife holder H. Handle for knives, nickelled I. Section stretcher to fasten on knife, by Prof. Mayer J. Apparatus for regulating flow of spirit K. Two setting and stropping bevels for knives Jung's Slide Microtome, pattern Fig. 1602, consisting of— Iron stand, 27 centimetres long A. Object slide with movable clamp and simple vertical adjustment B. Freezing apparatus, with blower and bottle . . C. Micrometer screw to cut exactly to o.ooi mm. . . • D. Three Jung's knives, 17 centimetres (a, b, and c), at I3/- E. One case for three knives . . F. Knife holder G. Handle for knife, nickelled H. Two setting and stropping bevels for knives . . cL £75° 4 15 o 2 15 O 2 12 O 2 O O 070 046 O K) O 040 0 12 6 1 7 o 046 £4 10 o 2 IO O I 8 6 i 15 o I 19 o 046 O 10 O 040 046 1605' Jung's Slide Microtome, consisting of — Bronze Stand, 27 centimetres long A. Object slide, with vertical movement of object, by Prof. Mayer and E. Schobel B. Micrometer screw, capable of adjustment within intervals of 1 mikron with quick return motion C. Two Jung's knives, 17 centimetres (b) for paraffin, at I3/- D. Case for knives . . E. Knife holder with adjustment to turn the knife around its edge F. Handle for knife, nickelled G. Section Stretcher (Prof. Mayer's) H. Long thumb screw for knife block, in conjunction with plates . . I. Setting and stropping for knives J. Zimmer's strop, quadrilateral, large pattern, 23 centimetres K. Strop paste, red or black . . L. One set of three plan parallel plates to lay under knife holder . . £"t> 5 o 300 2 l6 O i 6 o 0 4 1 IO o 4 O 12 O 2 O 2 0 0 0 O o 0 6 6 5 6 1 o 2 6 £22 16 6 £13 5 6 1605 £16 11 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 311 1607T Schanze's Microtome. 1607 A. B. C. D. E. F. G. H. I. J- Length of cutting plane, 25 centimetres ; size of clamp 4 by 3 centimetres Freezing apparatus Embedding arrangement . . Arrangement for cutting to i mikron Mechanical adjustment of knife Adjustment to two angles One knife, 17 centimetres . . One knife for paraffin, with adjustable handle Two cases for knives One clamp for knife, simple form Polished mahogany case . . 1608' Schanze's Microtome, same style as No. 1607. Length of cutting plane, 30 centimetres ; size of clamp 6 bv 4 centimetres A. Freezing apparatus B. Embedding arrangement . . C. Arrangement for cutting to i mikron D. Mechanical adjustment of knife E. Adjustment to two angles F. One knife, 20 centimetres . . G. One knife 20 centimetres, for paraffin, with 'adjustable handle ti. Iwo cases for knives I. One clamp for knife, with adjustment J. Polished mahogany case . . £800 i 5 o o i 17 6 300 350 1 5 o i 2 6 0 12 O 090 1 8 o £io I I 2 0 15 15 10 0 0 0 6 4 3 I 0 15 12 o 6 i o i 10 J7 5 15 o 6 0 0 £23 11 0 — £30 15 6 BAIRD &TM1OCK (LONDON) LTD. 1609 1609' Schanze's Microtome. This microtome can be used for cutting sections in paraffin, celloidin, or in frozen gum. Schanze's microtome differs from Jung's microtome in the following way :— The object-carrier is fixed at the commencement of the knife-slide, so that the knife can be used throughout its entire length. The object-carrier consists of a clamp with two adjustable axes at right angles to each other, thus permitting of adjustment in any position • it is moved vertically by means of a micrometer screw to which a large disc is attached. The edge of tl disc is milled, and graduated, each degree of the graduation representing an elevation of the object-earner by I mikron. Stand suitable for cutting sections of 20 centimetres, size of clamp 4 by 2 centimetres A. Freezing apparatus B. Embedding arrangement . . C. Arrangement for cutting to I mikron D. Adjustable to two angles . . E. One knife, 14 centimetres . . F. One case for ditto G. One knife for paraffin, 17 centimetres, with adjustable handle . . H. One case for one knife and handle . . I. Clamp for knife .. J. Polished mahogany case . . £5 o 0 I 5 o I 7 o 1 17 6 2 15 0 0 15 o o 4 6 I o o 0 5 o 0 9 0 I 5 o £16 3 0 Any other pattern of Microtome obtained specially to order. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &TATLOCK (LONDON) LTD. 1610-1611 1610' Minot's Microtome, Model No. I. Having a length of 45 millimetres, and giving a surface for cutting of 40 by 50 millimetres, and 35 millimetres long, cutting sections of :•&> sV 71*. Tib. T*O. and I ^o, millimetre thick. Total size. 17 by 20 by 18 centimetres, weight 8 kilo. Price, in polished mahogany case with one set cement plates, 20, 30, and 40 millimetres diameter, with one knife 15 centimetres 1611' Support for sections, Fig. D .. .. .. .. .. .. extra In this instrument the knife is fixed, and the block of paraffin containing the object is successively raised, pushed forward, and lowered, by turning the handle. This microtome is most suitable for cutting rapidly along series of sections in paraffin. (See No. 1613 A to H for Accessories.) £11 14 6 £126 1612 1612' Minot's Microtome, Model No. II. This Microtome is same as No. 1610, but has automatic fine adjustment and is capable of cutting sections to I mikron. To cut the finest section remove the capstan wheel (G) and raise the lever (j) by unscrewing (K) until the wheel (c) is in contact with wheel (B), The capstan wheel (E) is now turned until the required stroke is reached, allowing sections to be cut, i, 2, 3. 4, 5 or 6 mikrons. To cut larger sections, lower lever (j) until wheel (c) is out of contact with (B), replace capstan wheel (G) and proceed as before. The shortest point on capstan (E) -^ revolution of wheel (c). Price, in mahogany case (See No. 1613 A to H for Accessories.) £14 10 0 CROSS STRET • HATTCHSr GARDETST, E- C BAIRD (^IXTLOCK (LONDON) LTD, 1613 1614 1613' Minot's Microtome, Model No. III. Of larger dimensions than Model I., having a length of 62 millimetres, and giving a surface for cutting of 55 by 60 millimetres and 45 millimetres long. With automatic adjustment for half and whole mikron, and a second knife stand for oblique lying knife, including one set cement plates, and one object clamp for wooden block. Also suitable for celloidin preparations. Sections cut from J to 40 mikrons. Price, in polished mahogany case £16 16 0 Accessories, extra — A. Support for sections . . . . . . . . . . . . ..£126 B. Microtome knives with handle, length 15 centimetres, back thickness 9 millimetres £0 14 0 C. Microtome knives with handle, length 15 centimetres, back thickness II millimetres (for hard objects) . . . . . . . . . . . . ..£0156 D. Case for one knife . . . . . . . . . . . . ..£030 E. ,, ,, two knives . . . . . . . . . . . . ..£040 F. Object clamp for cork . . . . . . . . . . . . ..£076 G. Object clamp for wooden piece . . . . . . . . . . . . £0100 H. Cement plates, set of three (20, 30, and 40 millimetres) . . . . . . £040 1614' Minot Microtome, by I.eitz, with ribbon conveying attachment .. .. ... £900 A1614-1615 A16141 Reichert's Medium Sized Sledge Microtome B, with automatically rising object- holder. The track is 300 millimetres^ 12 inches long £5 19 0 BAIRD & TXTLOCK (LONDON) LTD. 1615' Reichert's Microtome as above, with Naples object-holder instead of the ordinary holder, fitted with ball and socket joint £750 1616r Jung's Knife, fitted in case 12 cm. 10/- 1617' Thoma's Knives in case. 12 cm 14 cm. 14 cm. 14/6 16 cm. 12/9 each. HIT. 1618 CO., Freezing Microtome (A. Becker's), as used by Prof. Aschoff. used in conjunction with a C02 cylinder. (See page jiy for prices). The microtome is In this Microtome the knife is supported by a radial arm, pivoted between two centres, and made to describe an arc of a circle. The object rises automatically by means of a micrometer screw, provided with a toothed wheel, which advances at intervals of one to ten teeth. Any paraffin cutting knife having a length of not less than 6 cm. may be employed. It is important to note that the knife may be shifted laterally and that, accordingly, it can be utilized throughout the greater part of its blade. The clamp can be turned about a vertical axis. Obviously, the preparation must be so adjusted that the line of its greatest resistance is at right angles to the cutting edge. The object block is roughly adjusted with respect to the knife-edge by lifting or depressing the clamp in its sleeve, whilst the fine adjustment is effected bv turning the micrometer screw one way or the other by means of the crank fitted to the lower end of the screw. Before this can be done the knife-carrier should be swung right forward, otherwise the screw can only be moved upwards, but not downwards. The pointer should in this case be turned into its leftmost position. 14- -CROSS STREET • HATTOI GARDE1ST, E-C 316 BAIRD &TATLOCK (LONDON) LTD. To freeze with ether the microtome should be equipped with its ether spray apparatus. The latter is provided with a spray tube, which tapers towards the front so as to dimmish its tendency to clog, and to enable the operator to readily clean it at any time from the back with the aid 01 a tine orobe. The tubes, especially the one admitting tin: ether, should fit tightly, otherwise the atomizer will not work satisfactorily. The highest level of the ether in tin- spray-bottle should be 2 or 3 cm. above the plane of the freezing stage. It should also be noted that before m Txing preparations hardened in 10% formol, these should be lightly washed in 5%, or even more dilute, solutions ni [ormol (obtainable by the simple addition of water), since the presence of a strong solution of formol renders it nit, especially in summer, to reach the freezing point by the ether spray method. The supply of CO2 is regulated by a lever fitted to the freezing apparatus itself. Before turning this lever (lie valve of the cylinder, which should always be in an inverted position, should, of course, be opened slightly. A fresh cylinder should be stood quietly in its stand for half to one hour before using it. The valve should then be opened to expel any water which may have collected in the dome to obviate its passage to the freezing apparatus and consequent congealing within its interior. 1618T Microtome, of iron, with nickel-plated fittings, clamp and stage, and automatic adjustment £426 1619T Ditto with adjustment by hand . . . . . . . . . . . . £3 10 0 1620T Freezing Apparatus with ether spray, complete .. .. .. .. £0 16 0 1621r Additional Knife-clamp for tangential cutting . . . . . . . . £0100 1622T Knife .. .. .. .. .. '.. .. ..£056 1623r Case and Honing and Stropping Tube . . . . . . . . . . £036 1624T Carbonic Acid Freezing Apparatus .. .. .. .. £1 12 6 1625' Folding Stand for carbonic acid cylinder .. .. .. .. .. .. £0 10 9 1626' Box fitted with lock .. .. .. .. £0 10 6 1627 Aug. Becker's Small Student's Microtome for freezing by ether. It is, in particular, fitted with the same form of knife guide, seeingthat this has proved eminently satisfactory, microtome is provided with a simple form of automatic advance, and is available for use with an ether freezing ratus, an object clamp, and a disc to which the object may be luted. The automatic advance is much the .is that of microtome No. 1618. 1627T Automatic Microtome of iron with nickel-plated fittings, including an ether freezing apparatus, clamp, disc and knife . . . . . . . . . . . . £2150 1628T Box fitted with lock and key . . ..£086 1629r Aug. Becker's Small Student's Microtome with hand feed-ratchet No. 2 with object clamp and disc for celloidin and paraffin, including one knife . . . . . . £186 1630T Ether Freezing Apparatus for use with ditto . . . . . . £0110 1631* Box fitted with lock and key . . . . ..£060 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &.TATLOCK (LONDON) LTD. 1632-1635 1636-1638 1640 Microtome Knife, Thoma's model, plano-concave, with handle adapted for clamping to the knife carrier of the microtome. 1632T Length of cutting edge 36 centimetres .. .. .. .. ..£300 1633- 24 .. £1 13 0 1634- 17 „ £100 1635- „ „ „ 12 „ . . . . £0 14 0 Microtome Knife, Jung's model, plano-concave (requires knife-holder). 1636T Length of cutting edge 24 centimetres .. .. .. .. ..£16 1637- „ „ „ 17 .- £0 13 0 1638T „ „ „ 12 .. .. .. £0 11 0 1639' Microtome Knives of finest English steel (Sheffield make). 4f in. 6J in. 8 in. gj in. 12/6 16/6 25/- 30/- each. 1640T Bardeen's Small Microtome by Leitz. This microtome consists of a hollow cylinder, terminating below in "a. hexagonal nut by which it should be screwed to the gas cylinder. A hollow freezing stage with a spiral channel rises above. The interior of the cylinder communicates with the external air through a fine hole, through which the carbon dioxide rushes against the inner surface of the freezing stage after passing along the entire length of the spiral channel. The cylinder first described has sliding upon it another, carrying the knife-guides. These consist of two narrow strips of glass upon which the knife should be rested during the operation of cutting The desired thickness of the section is obtained by turning the graduated disc. Each interval corresponds to a thickness of o.ooi millimetre. In this form of instrument the freezing stage is fixed, whilst the knife-guiders rise and fall under the action of the micrometer screw and a counter spring. The microtome is attached to the gas cylinder in the following manner. After unscrewing the cap on the gas cylinder, remove the hexagonal nut screwed upon the lateral thread for its protection. Screw the microtome upon this thread, and draw it up tight with a spanner. Price £1 15 0 14 -CROSS STREET- HATTCHsT GARDEN, E-C 318 BAIRD &TATLOCK. (LONDON) LTD. 1641 1641T Demonstrator's and Student's Microtome. This handy microtome is chiefly adapted for rapidly preparing sections tor demonstrations or diagnosis. The knife is carried in a circle about an axis, journalled between two pointed screws, and the knife is so fixed as to give an oblique cut. The workmanship of the microtome is such that in point of stability and certainty of action, it satisfies the highest requirements, so that embedded objects and frozen objects may be cut with equal precision. Freezing may be effected with the aid of carbon dioxide and ether. Being simple in construction and management, and correspondingly inexpensive, it is well adapted for the use of students. It is attached to a table by means of a rectangular screw clamp, which is continued above into a rigid casting provided with two hardened centre screws, between which swings the axis of the knife-holder. This arrangement lias proved entirely satisfactory in the case of small microtomes. Should the knife-holder show any signs of play, loosen the nut at the upper centre by means of a tommy, take up the slack between the points, and re-tighten the nut. The knife-holder has the form of a bridge, and by reason of its outer form is extremely rigid, so that the knife cannot yield or vibrate. The knife is fixed by means of set screws in two recesses on the right and left side of the knife-holder. The vertical branch of the teeth clamp carries the object slide, which moves within dovetails. The micro- meter screw, for raising and lowering the slide, is journalled within a rectangular frame. The nut of the micro- meter screw is bi-valve and adjustable by a screw. The spindle carries a serrated disc. During the rotation of t lie knife-holder, the serrated wheel advances after each cut through a number of teeth, determined by the position of the stop. The adjustment is effected by the displacement of the lever, which carries the pointer. Each tooth corresponds to an elevation of the object, amounting to 0.005 millimetres. By turning the milled head below, the object may also be raised by hand. In this case the thickness is indicated by divisions inscribed on the disc. Each interval on the wheel corresponds to o.ooi millimetres. To return the slide to its original position, the ratchet pawl should be disengaged, whilst with the other hand the screw should be worked back. The object clamp slips into the hole bored into the object slide, and fixes with the aid of a set screw. With knife, blade 8 cm., and without freezing apparatus 1642T Carbonic Acid Freezing Apparatus for microtome No. 1640. This apparatus is attached to the cylinder by means of a flexible metal tube. By its means any preparation may be frozen within a few minutes. Over the ether freezing apparatus it has the advantage, that the state of congelation is reached much more rapidly, and may also be maintained for a longer period than is the case with ether. The connection between the gas bottle and cylinder is established by means of a flexible metal tube, which greatly facilitates the attachment and detachment of the apparatus. The gas cylinder, with its valve downwards, is placed on its stand. Any water which may be present is thus made to collect, and may be blown out after an hour's standing. The tube may then be attached to the gas cylinder by means of its union. In the case of freshly filled gas cylinders the elimination of the water should never be omitted, since in the event of its passing into the apparatus it would interfere with its proper working. After use the valve on the gas cylinder should promptly be closed £3 17 0 £1 10 0 SO CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS BAIRD &TATLOCK (LONDON) LTD. 1643 1644-1649 1643T Hand Microtome by Leitz. Consists essentially of an iron slide-like frame which is attached to the table by a stout screw clamp. The frame is fitted on top with two narrow glass strips 70 millimetres long, which serve as guides for the knife. The object carriage moves at right angles to this within a V track, and is raised and lowered by a micrometer screw fitted below with a milled head having divided sleeve. Each division conforms to an elevation of the object of o.oi millimetre. The object slide has attached to it a hollow cylinder with clamping screw for fixing the object clamp and paraffin stage. All parts are enamelled or nickel-plated. Price without knife 1644T Minot Automatic Rotary Microtome, without knife 1645T Ribbon Carrier 1646T Object Clamp . . 16471 Object Disc, 25 millimetres 1648r Knives, 125 millimetre blade, without handle .. .. .. .. each 16491 Adjustable Knife Block for celloidin The Rotary Microtome was designed by Dr. Charles S. Minot, of the Harvard University Medical School. Kiom time to time improvements suggested by continual use and developed by us under Dr. Minot's directions have been added to the original instrument, until now it represents the highest attainment of mechanical excellence and accuracy in this line. It has been strengthened by the addition of a guard for the feed-wheel, which serves to protect it, and which at the same time, presents a very attractive appearance. All clamps and milled heads are easily operated and accessibly placed. The slides and working parts are fitted with the utmost nicety, with provision for taking up wear. The fly-wheel is so perfectly balanced that the instrument operates with the utmost smoothness and the least expenditure of energy. The object carrier is adjustable in three planes and can be rigidly clamped. The knife is adjustable in three planes — to and from the object, from side to side, and the edge of the knife can be tilted with reference to a vertical plane. This last adjustment is secured by means of a carefully-fitted socket, which carries the knife, and which with the knife can be rotated in any position and fastened by set-screws. An adjustable screw for serial ribbons attaches to the knife carrier, if desired. The feed is controlled by an adjustable cam, giving cuts from i to 25 microns in steps of one micron, and is absolutely reliable for all these various thicknesses. The impact on the cam is by roller, and both this and the cam are of hardened steel, accurately ground. A great saving of time is effected by the split nut (with handles) and the releasing lever. The carriage may thereby be instantly brought to the beginning position or to any intermediate position and then held. The fly-wheel can be turned either forward or backward and there is no way of damaging the screw even if operated after it has been fed out to the last thread. This microtome is regularly supplied with three object discs, to which the objects to be cut can be cemented. A clamp for holding specimens mounted upon blocks is furnished at an extra cost. We can furnish, also on special order, an object clamp having the sides open and the back closed. This clamp ran be attached by its post in place of the discs and orientated by means of the regular holder. An extra knife carrier with adjustable clamp for holding the knife edge at any angle with reference to a hori- zontal plane, for celloidin cutting, is also furnished at an extra cost. This microtome is limited, however, for celloidin work, to objects one-half inch square. Dimensions : Length of base 200 mm., height 178 mm. The instrument is packed in a strong wooden box with handle. £1 10 -CROSS STREET • HATTOTST GARDEN, E'C Section V BALANCES & WEIGHTS Balances, Assay Becker Bunge Lecture Oertling Physical or Student Ruprecht Sartorius Specific Gravity Spring Weights, Analytical Assay Physical 353-360 334, 34 l.and 353 335-339 327-330 342.347. 354-361 321-326. 331 329-330 348-351 362-364 368-369 370-375 376 377-381 Balances cleaned and adjusted in our own Workshops. 14. CROSS STREET. JHATTON GARDEN. E.G. f^r* BAIRD &.TATLOCK (LONDON) LTD. The following are the different Sections Catalogue. Those marked * are also separately. Section No. 1.* Laboratory Fittings 2.* Bacteriological Apparatus 3. Chemical Physiology Apparatus 4.* Microscopes and Microscopical Accessories 5.* Balances and Weights 6.* Chemical Apparatus 7.* Botanical Apparatus 8. Gas Analysis Apparatus 9." Milk Analysis Apparatus 10. Refractometers 11.*' Oil Analysis Apparatus 12. Water Analysis Apparatus 13. Cement Testing Apparatus 14. Leather Testing Apparatus 15. Paper Testing Apparatus 16. Physico Chemical Apparatus 17.* Pyrometers 18.* Calorimeters 19.* Seed and Soil Analysis Apparatus 20.* Spectroscopes and Polariscopes 21. Volumetric Apparatus 22. Anatomical Models 23. Meteorological Apparatus 24.* Assay Apparatus 25.* Chemicals in our printed Pages NOE. 14-56 57-161 162-192 193-320 321-382 383-816 817-842 843-886 887-894 895-902 903-926 927-933 934-946 947-949 950-951 952-976 977-1006 1007-1022 1023-1042 1043-1078 1079-1087 1088-1105 1106-1124 1125-1172 1187-1246 CROSS STREET- HATTCTN GARDEN, E- C BAIRD &TATLOCK (LONDON) LTD. SECTION No. 5. BALANCES. Physical, Chemical, Assay, 6?c., Weights. 1660 1661 1660' Balances for Physical Experiments, etc., brass beam suspended on hook from iron pillar, on polished sole. To carry . . . . . . roo 250 500 grammes. Sensitive to .... 4 5 10 milligrammes. Price .. .. 10/- 11/6 14/- Specific Gravity Pan, 4/6 extra. 1661' Balances for Physical Experiments, etc., with arrangement for lowering and raising beam, on polished sole. To carry . . . . . . 100 250 500 grammes. Sensitive to .... 4 5 ™ milligrammes. Price .. .. 15/- 16/6 19/6 Specific Gravity Pan, 4/6 extra. BAIRD &TATLOCK (LONDON) LTD. 1662 1662" Balance, new pattern, for students, 250 grammes capacity, sensitive to 4 milligrammes, steel knife edge in centre of beam, double hooks for suspending stirrups and for specific gravity experiments, pans 10 centimetres diameter, levelling screws and plummet, mounted on polished wood base . . . . . . . . . . . . each 1663U Physical Balances, solidly constructed, with steel knife edges on agate planes, levelling screws and plummet, beam support and double hooks for suspension, on polished mahogany sole. To carry . . . . zoo 250 Sensitive to . . 2 2 Diameter of pans . . 8 10 Price .. .. £1 10 0 £1 17 6 £250 £0 18 6 500 5 12 £2 5 1 ,000 grammes. 10 milligrammes. 15 centimetres. £276 1664 1664" Balance, well made, to carry 250 grammes, sensitive to i milligramme, with agate knife edges and bearings, improved rest for beam so arranged that the knife edges are not in contact with the planes when balance is at rest, beam divided on one side, pillar fitted with plummet, on polished mahogany sole with levelling screws . . £1140 16651' Balance, as above, fitted in polished mahogany case with sliding glass door, so arranged that the balance can be lifted out when required (as Fig. 1667) • • ' • . £296 CROSS STREET • HATTCXN GARDEN, E-C 322 BAIRD &TATLOCK (LONDON) LTD. 1666" Physical Balances, solidly constructed with agate knife edges on agate planes, levelling screws and plummet, etc., as No 1663. To carry Sensitive to Price 100 2 £1 13 6 250 grammes 2 milligrammes. £220 1667 16671 Physical Balances, similar to Fig. 1663, in polished mahogany case, with sliding door. Arranged so that balance can be taken out of case if required To carry Price 100 250 500 £220 £2 12 0 £330 1,000 grammes. £3 12 0 1668L Physical Balances, all agate knife edges, similar to No. 1666, in polished mahogany case (as in Fig. 1667). To carry Price 100 £260 250 grammes. £2 16 6 BAIRD &TATLOCK (LOM)ON) LTD. Section of improved form of beam support (Fig. 1669). The links are not suspended from knife edge when Balance is at rest. 1669 1670 1669° Balances, Becker's, with open beam, all bearings of agate, with improved support for beam and links (see illustration). Specially designed for students' work. To carry . . . . 100 250 500 1,000 grammes. Sensitive to . . 2 2 5 10 milligrammes. Diameter of pans 8 10 12 15 centimetres. Price .. £1 12 0 £1 15 0 £2 10 0 £2 15 0 1670" Balances, as above, fitted in polished mahogany case with sliding door. Balance can be removed from case. To carry . . . . 100 250 500 1,000 grammes. Sensitive to . . 2 2 5 10 milligrammes. Pnce .. ..£270 £2 12 0 £380 £3 19 0 CROSS STREET • HATTO^rST GARDEN, E-C 324 BAIRD &TATLOCK (LONDON) LTD. 1671" Balances, Physical, new pattern with Magnalium beam and pillar. These balances are fitted with Magnalium beams, pillar, and pans (this metal in addition to being light and strong is not affected by acid fumes, etc.), and they are thus specially suitable for students' use. Beam open pattern, agate knife edges and planes, improved support for hangers, and plummet. To carry . . . . 100 250 500 grammes. Sensitive to . . 2 2 5 milligrammes. P"ce . . £1 8 6 £1 10 0 £1 15 0 each. 1672° Balance, Physical, Magnalium beam and pillar as above, but with beam divided one side as illustrated. To carry . . . . . . 100 250 500 grammes. Sensitive to .... 2 2 5 milligrammes. Pr)ce .. .. .. £1 11 6 £1 13 0 £1 18 0 each. 1673 1674 1673" Balance, Physical, to carry 250 grammes, and sensitive to 2 milligrammes. Steel knife edges working on agate planes, with plummet, on wooden sole with levelling screws, double pointer, and indices (back and front) for class demonstration . . . . . . £24 1674U Balance, Physical, same as above, but fitted in glass case with sliding door . . . . £31 0 if] CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 325 BAIRD &.IWLOCK (LONDON) LTD. SAJRD St TAT LOCK. LONDON)Lr 1675 1675" Balance, Physical, to carry 2 1 kilos, sensitive to 50 milligrammes, pans 18 centimetres diameter, with plummet and levelling screws on mahogany sole . . £3120 Al675u Balance, as above, in polished case with counterpoised sliding front. . £570 1676 1676U Balance, Lumsden's pattern, with double beam, suitable for physical and chemical use to carry 250 grammes, sensitive to i milligramme, fitted with agate knife edges and bearings, hooks for specific gravity, plumb bob and levelling screws, on polished sole DESCRIPTION. This balance has been designed by Mr. Lumsden specially for students' work. No free weights smaller than I gramme are required, the lower values down to milligramme are made in the shape of rings, and are permanently kept over the beams. The right arm of beam has ten divisions, and decigrammes are found by i-gramme rider and centigrammes by a decigramme rider. The riders when not in use, are supported on a hook screwed in brass block on top of centre rod. In order to make weighings such as 0.22 or 0.55 gramme possible, a groove is made on the larger rider so that the smaller one may rest on it. A light beam, one-fifth of the length of the main beam is used for milligrammes ; it is divided on each side of the centre into ten parts, and a 5-centigramme ring rider' is used This rests on the central division when not in use. Among other advantages claimed for this balance are the following : — (1) A saving of time, no small weights being used on the pans. (2) Great accuracy, the total weight being read off directly, and there can be no error due to addin» small weights together. (3) No loss or damage to small weights. The balance will carry 250! grammes in each pan, and weigh to I milligramme. £276 CROSS STREET ; HATTCJN GARDEN, E- C BAIRD &TATLOCK (LONDON) LTD. 1677 M. \J * I 1677" Balance, Lecture, to carry i kilo in each pan, sensitive to 10 milligrammes, steel knife edges on agate planes, movable pans 15 centimetres diameter, and extra pan with hook at base for specific gravity, provided with levelling screws and plummet, on polished mahogany sole . 1678 1678" Balances, as described No. 1679, mounted on mahogany sole, with levelling screws and plummet, etc. Capacity . . . . . . 2 5 kilos. Price £660 £7 15 0 £2 16 6 327 BAIRD &L TATLOCK. (LONDON) LTD. 1679 1679" Balances for Chemical and Technical Work, fitted with eccentric lever arrangement and beam support, and mounted in polished mahogany case with counterpoised sliding door. The beam is made of brass, lacquered, and is fitted with steel knife edges and adjusting screws. Balance is provided with agate planes, levelling screws, and plummet, also square pans without rim to enable large objects being weighed. The sensibility is equal to nnsW<5 PaT"t °f maximum load — Capacity Length of beam Width of stirrups Price 2 41 14 £880 5 kilos. 46 centimetres. 15 £10 15 0 14 -CROSS STREET • HATTCTN GARDEN, E-C 328 BAIRD &TATLOCK. (LONDON) LTD. 1680 1681 1680" Balance, Ruprecht's, for Chemical Lecture Demonstration, specially adapted for demon- strating the weight of gases and increase of weight caused by oxidation, etc. With a load of 5 kilos in each pan, the balance is sensitive to .02 gramme, and the deviation of the pointer can be observed at a distance of 50 metres. The balance is fitted with two glass cylinders of equal weight, and each having a capacity of about 2 litres, two polished glass discs for hermetically closing the cylinders, and two horse-shoe magnets of equal weight 1681L Hydrostatic and Experimenting Balance, to carry i kilo, sensitive to 100 milligrammes. Price of this balance, lacquered (inclusive of two brass weights of 200 grammes each and of 100 grammes) This balance is provided with a hinged beam-support and with a pair of long stirrups with pans, and a pair of short stirrups with pans, which are interchangeable. The beam has at each end two adjustable knife-edges and two suspenders between, above and below the plane level ; there is only one pointer and one scale. The tripod is of iron, but the beam, supports, pans and levelling screws of brass. Upon one of the three feet a spirit level is fixed to adjust level to balance. The following instructive experiments may be carried out with this balance : — Dividing the beam. Transposing the point of gravity. Elongatin" the beam. Suspending weights above and below the plane level of beam. Hydrostatic balance. ! ii £16 10 0 £6 10 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &.TATLOCK (LONDON) LTD. 1682 1682" Balance, Ruprecht's, for Class Demonstration, to carry i kilo in each pan, sensitive to .02 gramme, with two cylinders, discs, and magnets, as illustrated . . . . £7 15 0 CROSS STREET • HATTCTSr GARDEN, E-C BAIRD &TATLOCK (LONDON) LTD. 1684 1684" Balance, Student's .. This balance has been devised to meet the demand for a cheap and accurate balance suitable for students' work. It is thoroughly well made, all knife edges and bearings being of agate ; carrying a load of 100 grammes in each pan, it is sensitive to i milligramme ; no steel is used in the construction. It is fitted with beam support, double hooks "for taking specific gravities, level- ling screws and plummet. Pans 8£ centimetres diameter. Mounted in polished mahogany glass •case with counterpoised sliding front. £2 10 6 1685 1685" Balance, similar to above (No. 1684), but case fitted with drawer I £2 18 6 QCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS, H! BAIRD &TATLOCK (LONDON) LTD. 1686 1686'J Balance (as Fig. 1684) without glass case, mounted on mahogany sole with levelling screws • • 1687 1688 1687" Balance, Chemical, to carry 100 grammes, sensitive to | milligramme, in polished mahogany glass case with drawer, brass levelling screws and plummet, all knife edges and bearings of agate, no steel or iron used in construction. The beam is divided and fitted with rider apparatus. Gilt pans 10 centimetres diameter, double hook for taking specific gravities, with specific gravity table 1688" Balance, Analytical, to carry 100 grammes, sensibility ! milligramme. Magnalium beam, agate knife edges and planes, rider apparatus in glazed case of Magnalium £4 10 £3 17 6- CROSS STREET • HATTCTNT GARDEN, E'C 332 BAIRD &.TATLOCK (LONDON) LTD. 1689 1689" Balance, Chemical, short beam, of phosphor bronze, knife edges and bearings of agate, to carry 200 grammes, sensibility ^a milligramme. Length of beam 14 centimetres, mounted on black plate glass sole, in walnut case, glazed, without side doors 1690 1690" Balance, Analytical, with rigid brass beam 20 centimetres long, one side of beam gradu- ated and with rider apparatus, agate knife edges and bearings. Load, 200 grammes ; sensibility, 0.5 milligrammes. Case polished and glazed all sides, and with drawer at base for weights, etc. ; levelling screws and plummet £6 15 0 £4 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 333 BAIRD &TATLOCK (LONDON) LTD. 1691 1692-1693 1691" Student's Balance, Becker's, in polished mahogany glass case, with counter- poised sliding front, steel knife edges, and needle pointer, nickel-plated pans, to carry 30 grammes in each pan, and turn to | milligramme 1692U Balance, Becker's Chemical, in polished mahogany case, with counterpoised sliding front, movable pans, to carry 50 grammes, sensible to f milligramme 1693" Balance, Becker's Chemical, as above, with agate knife edges and planes 1694° Balance, Becker's Chemical, as Fig. 1692, but with rider arrangement and beam divided on one side 1695" Balance, Becker's Chemical, as Fig. 1692, with rider arrangement, beam divided, and agate knife edges and bearings 1696 1696U Balance, Becker's Chemical, to carry 50 grammes in each pan. In polished glass case, sliding front counterpoised, beam divided on one side in J parts of milligrammes. With new improved arrangement for arrest of pans. Provided with wood stand for taking specific gravity, sensible to ~ part of a milligramme with its full charge. Pans 6 centimetres in diameter. Pans and bows nickel-plated, provided with one rider apparatus, knife edges, and bearings of agate £290 £2 15 £3 5 £3 10 8 £408 £6 18 0 CROSS STREET • HATTCTK GARDETST, E-C BAIRD '&L TXTLOCK (LONDON) LTD. Bunge's Short Beam Chemical Balances. All genuine Balances have the name " PAUL BUNGE " stamped conspicuously on the beam. AGENTS : BAIRD & TATLOCK (LONDON), LTD. All Bunge's Balances have the zero point of scale at the left-hand end of the beam, so that the entire length of scale can be used uniformly throughout, and the mistakes frequently made through confusing " plus " and " minus " are obviated. The Balance should be counterpoised, and brought into action with the rider set at O. 1697 1698 1697° Bunge's Balance, 1 E, to carry 200 grammes, sensitive to i milligramme, beam of bronze, gold plated, all bearings and points of contact of the beam of agate. Case with two side doors, but only one sliding front (no slide at back). Length of beam 13 centi- metres, divided by notches for rider, each notch equals T3ff milligramme. All swinging parts are of finely polished German silver. Price, mounted on black glass sole . . 1698" Bunge's Analytical and Technical Precision Balance, 1 D, to carry up to 200 grammes, sensitive to T15 milligramme. Specially recommended for rapid and accurate analytical work. Beam, 13 centimetres long, of gun-metal, with round pointer ; in place of a rider scale the beam itself is divided and graduated in 100 divisions, so that moving a 5 milligramme rider the full length of the beam will cause an alteration of the equilibrium of the balance by one centigramme. In this way milligramme weights are not required, one notch corresponding to every 0.1 milligramme, and every ten notches to one milligramme. The time of oscillation, with a medium load, is only 9 seconds, this being the shortest time in which the oscillations can be read off with certainty. Owing to the low situation of the centre of gravity the sensitiveness is the same for any load. The knife edges and planes, as well as all contacts of the beam and pan suspensions, are of agate. Price, with polished mahogany case, with doors opening on all sides, and mounted on black plate-glass sole with levelling screws £900 £10 0 0 BAIRD &TATLOCK (LONDON) LTD. 1699 1699" Bunge's Balance, 1 F, similar to Fig. 1698, but with mirror reading arrangement, in polished mahogany case, opening all sides. Load 200 grammes, sensitive to T1g milli- gramme. Price, mounted on black plate-glass sole In order to be able to read tenths of a milligramme direct from balance, without extending the time of oscilla- tion, a mirror lens (achromatic object lens, silvered), magnifying five times, is arranged at the foot of the pillar so as to reflect, on a magnified scale, without any disturbing reflexes or distortions, an opal glass scale arranged about 20 millimetres above the ivory scale, and divided into fifths of millimetres. The result in milligrammes is read off on the ivory scale, and to determine tenths of a milligramme it is only necessary to glance at the glass scale reflected in the mirror lens. Seeing that it is therefore, only at the final reading that the mirror is made use of, and as both eyes are employed, the sight is not fatigued in any way, and the two scales can be worked with the greatest satisfaction. £10 10 0 1700 1700° Bunge's Balance, 1 F, with telescope reading arrangement to read minute divisions on micrometer scale, similar in all other respects to Fig. 1699, >n polished mahogany case Load 200 grammes sensitive to T15 milligramme. Price, on black plate-glass sole .. £11 17 6 14 • CROSS STREET • HATTCnST GARDEN, E-C 336 BAIRD &TATLOCK (LONDON) LTD. 1704 1704" Bunge's Analytical Balance, 1 A, to carry up to 200 grammes, sensitive to TV milli- gramme. Beam of hard-rolled German silver plate, gold-plated, all swinging parts of finest highly polished German silver ; the bearings and all contacts of the beam, pan suspensions, and pan supports are of agate. The pointer is stamped out triangularly to avoid vibration. Beam 13 centimetres long, with rider scale divided in tenths by notches, showing i° for every tenth of a milligramme for all loads up to the maximum. Mounted on black plate-glass sole, polished edge. Pans of finest German silver, highly polished M 1J '1 n t £15 0 0 BAIRD &TATLOCK (LONDON) LTD. 1705 1706 1705" Bunge's Analytical Balance, 1 C, to carry up to 200 grammes, sensitive to TV milligramme. Beam of polished magnalium, a material almost equalling aluminium in weight and bronze in strength ; all swinging parts of finest German silver. The bearings and all contacts of the beam, pan suspensions and pan supports of agate. Beam 13 centimetres long, with rider scale divided in tenths by notches, showing i° for every tenth of a milli- gramme with a medium load. Mounted on black glass sole with pans of German silver, gold-plated £13 0 0 1706" Bunge's Analytical Balance, No. 2, in polished mahogany case, to carry up to 500 grammes, sensitive to TV milligramme. Beam of finest German silver. Knife edges and planes, as well as the contacts of the beam, pan suspensions and pan supports of agate. Beam 17 centimetres long, with rider scale divided into tenths by notches, showing i° for every tenth of a milligramme, with a medium load. All swinging parts and pans of finely polished German silver, pans gilt. Price, on black plate-glass sole £20 0 0 14 • CROSS STREET • HATTO^T GARDEN, E'C 338 BAIBD &TATLOCK (LONDON) LTD. 1707 1708 1707V Bunge's Physical and Analytical Balance, No. li.with arrangement for mechanically placing and removing the weights while the case is closed. Price, mounted on black plate-glass sole, and polished mahogany case The considerable advantages afforded by this balance to experimenters determining weights, and more especially to the busy analyst, are not shared by any other system of balances, and are as follows : — The weights are deposited exactly in the centre, and are thus entirely uninfluenced by friction, concussion, or fall. This is effected by purely mechanical means : in the first place, by removing a rod marked with the equivalent of weight, to the left, until contact ensues ; secondly, turning the crank from the position, indicated by a spring catch, to a position to be determined by contact ; and thirdly, moving back the rod, until contact is established, to the right. In order to move the weights, the process is reversed. With some practice, a determination of weight within one centigramme can be carried out, with the aid of this arrangement, within one-third of the time required if the weights have to be manipulated with the forceps £24 15 0 1708 Balance, Kuhlmann's Short Beam, in glass case, with counterpoised sliding door in front, sliding door at back, and two side doors, black polished glass base plate, agate knife edges and planes, 13 centimetre beam, capacity 200 grammes, sensitive to ^ milligramme. Sensibility constant with all weights. Apparatus for arrest of beam and pans, improved rider movement, magnifying arrangement for pointer. The scale of 20 divisions is on the back of the ivory plate, and is reflected by means of a concave mirror to the eye ef the operator. Weights less than the decigramme are not used for the pans. Fractions of the milligramme are shown by the pointer £12 10 0 339 BAIRD &TXTLOCK (LONDON) LTD. A 1708 Al708u Balance, Oertling's No. 3b Chemical, with i2-in. beam, to carry 100 grammes in each pan, and turn with y1^ of a milligramme ; the beam support descends; the three knife edges are of agate, and work on agate planes ; apparatus for moving the rider ; polished mahogany glass case with counterpoise weights and adjusting screws, with pan supports, Circular pans supplied if required £11 11 0 B17081 Balance, Oertling's No. 3b Chemical, as above, with pan supports and plate-glass to bottom of case £13 13 0 CROSS STREET • HATTOlSr GARDEN, E-C 340 BAIRD &TATLOCK (LOM)ON) LTD. Becker's Short Beam Balances. 1709 1709U Balance, Becker's Short Beam, for a charge up to TOO grammes in each pan. In polished mahogany glazed case, front sliding frame counterpoised, beam divided one side in % part of milligrammes. With new improved arrangement for arrest of pans. Provided with wood stand for taking specific gravity, and sensible to -^ part of a milli- gramme. Pans 6 centimetres in diameter, width of bows q centimetres. Pans and bows nickel-plated, with one rider apparatus, agate knife edges and bearings £8 10 0 1710 1710° Becker's Short Beam Balance, in polished mahogany glazed case, front sliding frame counterpoised, for a charge up to 125 grammes in each pan, sensitive to r'n milligramme. With new improved arrangements for arrest of pans and beam. With divided beam and one rider apparatus, and arrangement for taking specific gravity. Nickelled pans 3 in. diameter, with agate knife edges and bearings .. .. .. .. £11 5 0 341 BAIRD &TATLOCK (LONDON) LTD. Oertling's Short Beam Balances. ' 1711 1711" Oertling's Short Beam Balance, No. 18, with 6-in. beam, with agate knife edges working on agate, to carry 100 grammes in each pan, and turn with 0.5 milligramme ; fitted with rider-slide traversing total length of beam ; pans 3^ in. in diameter and pan supports ; hooks for taking specific gravities ; circular spirit level ; polished mahogany glass case, with three levelling screws and front slide fitted with counterpoise weights £9 10 0 CROSS STREET • HATTOK GARDEN, E-C 342 BAIRD &TATLOCK (LONDON) LTD. 1712 1712U Oertling's Chemical Balance, Short Beam, No. 30, with 6-in. beam, to carry 100 or 200 grammes in each pan, and turn with o.i milligramme ; agate knife edges working on agate planes ; pan supports ; rider-slide, which traverses the entire length of the beam ; polished mahogany glass case, with counterpoise weights to front slide ; mounted on metal and plate-glass base ; three levelling screws and level. This balance is fitted with side-action Specially constructed to reduce to a minimum the effect of all surrounding vibrations. £17 0 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 343 BAIRD &TATLOCK (LONDON) LTD. 1715 1713" Balance, Oertling's Short Beam No. 1, with 8-in. beam, agate knife edges and planes, to carry 100 grammes in each pan, and turn with o.i milligramme. Fitted with double rider-slide, front of mahogany, glass case, with counterpoised weights, with pan supports 1714" Balance, Oertling's Short Beam, No. 1, as above, but with plate-glass to bottom of case 1715" Balance, Oertling's Short Beam, No. 2, with 6-in. be'am, to carry 200 grammes in each pan, and turn with o.i milligramme ; agate knife edges working on agate planes ; rider- slide, which traverses the entire length of the beam ; plate-glass to bottom of case ; polished mahogany glass case with counterpoise weights fitted to front slide, with pan supports If desired, this instrument can be made with a beam to carry 500 grammes in each pan, without extra cost. £13 13 0 £15 15 0 £18 18 0 CROSS STREET • HATTOTST GARDETST, E; C 344 BAIRD ^TXTLOCK (LONDON) LTD. 1716 1716' Balance, Oertling's No. 3, with 6i-in. triangular beam, to carry 500 grammes in each pan and turn with o.i milligramme ; agate knife edges working on agate planes : pan supports and rider-slide which traverses the entire length of the beam ; polished mahogany case with drawers and doors at each end as illustration ; counterpoised weights fitted to front slide £21 0 0 1717 Balance, as above, with plate-glass fitted to bottom of case £23 2 0 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCKL (LOM)ON) LTD. 1718 1718" Balance, Oertling's No. 5 Short Beam, with 8-in. 'beam to carry 250 grammes in each pan, and turn with o.i milligramme ; agate knife edges working on agate planes ; rider traverses entire length of beam ; support for pans ; polished mahogany glass case with counterpoise weights fitted to front slide 1719U Balance, as above, with plate-glass fitted to bottom of case £21 0 0 £23 2 0 STREET • HATTON GARDE'N, E-C BAIRD &TXTLOCK (LONDON) LTD. 1720 1720' Balance, Oertling's No. 6 Short Beam, with 61-in beam, to carry i kilo, in oach pan and turn with o.i milligramme ; agate knife edges working on agate planes ; rider-slide which traverses the entire length of the beam ; polished mahogany glass case with counterpoise weights fitted to front slide, fitted with pan supports 1721' Balance, as above, with plate-glass fitted to bottom of case . . £21 0 0 £23 2 0 BAIRD &TATLOCK (LONDON) LTD. Sartorius' Short Beam Balances. 1722-1723 1724-1725 1722 Balance, Sartorius' Short Beam, No. 8a, special pattern for Works Laboratories, with triangular beam of phosphor bronze; all knife edges and planes of agate ; pans of German silver ; black plate-glass sole with pan supports ; to carry 100 grammes, sensitive to .2 milligramme 1723' Balance, as above, to carry 50 grammes, sensitive to .2 milligramme £7 5 1724" Balance, Sartorius' Short Beam, No. 7, knife edges and agate planes, platinum-plated pans, base of black plate-glass, with pan supports, one rider apparatus, and beam divided into i milligramme. Length of beam, 18 centimetres ; sensibility, 0.2 milligramme ; to carry 500 grammes. . . . . . . . . ..£110 1725' Balance, as above, with beam 14 centimetres long, to carry 200 grammes, sensitive to 0.2 milligramme . . . . . . . . • . . . . . . . . . £715 CROSS STREET • HATTO^J GARDEN, E- C 34-8 BAIRD &TATLOCK (LONDON) LTD. •==811 1726 1727-1728 1726" Balance, Sartorius' Short Beam, U.S.A. Model, with triangular beam ; all knife edges and planes of agate, black glass sole and pan supports ; to carry 200 grammes, sensibility o.i milligramme, with one rider apparatus . . . . . . . . . . £8150 1727U Balance, Sartorius' Short Beam, No. 6, with beam of phosphor bronze, with agate knife edges and bearings, divided into 100 divisions on either side of centre, with rider- slide ; to carry 200 grammes, sensitive to .1 milligramme, on black plate-glass sole, with pan supports . . . . . . . . . . . . . . £9 15 0 1728U Balance, as above, to carry 500 grammes, sensitive to .15 milligramme £12 5 0 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 549 BAIRD &_ TATLOCK. (LONDON) LTD. 1729 1729° Balance, Sartorius' Short Beam, No. 5, with beam of phosphor bronze, divided for use with rider into 100 divisions on either side of beam, all knife edges and bearings of agate, rider apparatus and pan supports, on black plate-glass sole, to carry 100 grammes, sensitive to 0.05 milligramme . . . . . . . . . . £13 0 0 A1729 Balance, as above, to carry 200 grammes, sensitive to o.io milligramme 1730" Balance, as above, to carry 500 grammes, sensitive to 0.15 milligramme £13 5 0 £17 17 0 CROSS STREET • HATTOTST GARDE1ST, E- C 350 BAIRD &L TATLOCK (LONDON) LTD. 1731 1731U Balance, Sartorius' No. 3, Analytical Balance in hexagonal aluminium case, fitted with two doors. The Balance is made with phosphor bronze beam, adjustable end knife edges, and compensating suspensions, agate knife edges and planes and platinum plated pans, fitted with new rider lifting arrangement. Length of beam 14 centimetres, sensitive to .1 milligramme, capacity 200 grammes 1732U Balance, as above. Length of beam 12 centimetres, sensitive to .05 milligramme, capacity 100 grammes £23 0 0 £23 0 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 351 BAIRD &TATLOCK (LONDON) LTD. 1733 Balance, Short Beam, No. 4, for physical and analytical purposes. Simple but very precise construction with short-armed beam made of phosphor-bronze, constructed in one piece, with rider arrangement Cone-shaped pillar, concentric- arrester, improved compensating suspensions, scale pans platinum plated, knife edges and planes of agate. Suspensions densely gilt. In polished mahogany case, with side doors, back and spring or counterpoised front slide, mounted upon thick plate glass base. 1733" Balance, length of beam, 12 centimetres ; sensibility, o.i milligramme ; load, 100 grammes 1734U Balance, length of beam, 14 centimetres ; sensibility, o.i milligramme ; load, 200 grammes .... .... 1735U Balance, length of beam, 18 centimetres ; sensibility, 0.2 milligramme ; load, 500 grammes £986 £986 £13 1 0 In 14 -CROSS STREET • HATTON GARDEN, E-C 352 BAIBD &L TATLOCK (LONDON) LTD. Becker's Assay Balances. 1736 1736" Assay Balance, Becker's, in polished mahogany glazed case, sliding frame counterpoised, for a charge up to 10 grammes in each pan. Agate knife edges and agate planes, with new improved arrangement for arrest of pans and beam. Needle deviates on scale 30 divisions for i milligramme. Beam divided on both sides in fa parts of milligramme £16 16 1738 1738" Becker's Assay Balance, in polished mahogany glazed case, sliding frame counterpoised. Charge, 25 grammes in each pan. Needle deviates on scale 20 divisions for i milligramme. Agate knives with agate bearings. Apparatus for rider. Rider can be placed on centre of beam and used from the o point £10 8 0 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. 1739 1739° Balance, Oertling's No. 8a Assay, with lo-in. beam, to carry 50 grammes in each pan and turn with o.i milligramme ; the beam is constructed with agate knife edges working on agate planes, and is divided for the use of the rider ; double rider-slide, pan supports ; polished mahogany glass case with counterpoise weights to front slide. Pans with rigid suspension if required 1740" Balance, as above, with plate-glass fitted to bottom of case £18 18 0 £21 0 0 CROSS STREET • HATTOTST GARDEN, E-C BAIRD &TATLOCK (LONDON) LTD. 1741 1741° Balance, Oertling's Assay, No. 9, with 8-in. beam, to carry 10 grammes in each pan, turning most distinctly with 0.05 milligramme. The beam is constructed with three edges of agate, and the pans are supported by agate planes, apparatus for moving the sliding weight, pan rests £18 18 0 1742° Balance, Oertling's Assay, No. 9, as above, with plate-glass fitted to bottom of case . . £21 0 0 2A BAIRD &TATLOCK (LONDON) LTD. 1743 1743" Balance, Oertling's Assay, No. 12a, with a beam 10 in. long, of an improved construc- tion, to carry 2 grammes in each pan, and turn with' o.oi milligramme. The beam is divided, and has agate edges working on agate planes. Apparatus for the use of sliding weights. Plate-glass fitted to bottom of the case . . . . . . . . . . £30 o e CROSS STREET • HATTCTrSr GARDETST, E- C 356 BAIRD &TXTLOCK. (LONDON) LTD. 1744 1745 1744' 1745' Balance, Oertling's Assay, No. 14 (as used by the Royal Mint), with 6-in. horizontal beam, to carry I gramme in each pan, and turn with 0.005 milligramme ; the beam is constructed with agate knife edges working on agate planes, and is divided into 100 parts ; fitted with double rider-slide and also two achromatic lenses ; plate-glass to bottom of case ; polished mahogany glass case with counterpoise weights fitted to front slide This Instrument is richly gilt. Oertling's Balance, No. 12 S.B.A. (as used by the Royal Mint), with 6-in. horizontal beam, to carry 2 grammes in each pan and turn with o.oi milligramme. The beam is constructed with agate knife edges working on agate planes (which are all relieved when not in use), and divided into 100 parts. Double rider-slide, plate-glass to bottom of case ; polished mahogany glass case with counterpoise weights fitted to front slide £40 0 0 £31 10 0 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 357 BAIRD &TATLOCK (LONDON) LTD. 1746 1747 1746 Balance, Oertling's Assay, No. 12 B (new pattern), with 4-in. (10 centimetre) beam, divided into 100 parts. The beam is constructed with agate knife-edges working on agate planes, and the end knife-edges are relieved when not in action. Sensitivity .005 milligramme. The pointer makes one complete oscillation in 10 seconds, and with o.i milligramme on beam shows 10 divisions on scale. Lenses for beam and index. Capacity i gramme in each pan. Single rider apparatus. Full sub-base plate-glass covering entire bottom of case, including table-part. Polished mahogany glass case with counterpoise weights fitted to front slide 1747" Balance Oertling's Assay, No. 11 C (new pattern). Capacity i gramme, sensitivity ij^j milligramme, with 4-in. (10 centimetre) beam, .inverted type; divided into 100 parts ; 50 divisions each side. The beam is constructed with agate knife-edges working en agate planes, and all knife-edges are relieved when not in action. The pointer makes one complete oscillation in 10 seconds, and with o.i milligramme shows 10 divisions on scale. Lenses for beam and index. Double rider apparatus. Two levels fitted to base. Full sub-base plate-glass covering entire bottom of case including table-part. Polished mahogany glass case with counterpoise weights fitted to front slide, and with adjusting screws £40 0 0 £40 0 0 CROSS STREET • HATTOTST GARDEN, E-C 358 BAIRD &TATLOCK (LONDON) LTD. 1748U Balance (new pattern), to carry 10 grammes, sensibility ^, milligramme with hardened steel knife edges and bearings ; length of beam 5 in., pans 2 in. diameter, size of portable box for the balance, 5 by 6 by 7 in. In this instrument an arrangement is provided, whereby the pointer gives twice as large a deflection with the same swing of beam, and over-all dimensions as other balances of similar pattern. The balance can be used as a portable or a laboratory instrument for assay or general chemical work. It is fitted with pan rests and lifter for beam, and is provided with adjustment for sensibility. Bearings are of best quality cast steel, hardened, and edges ground ; they are of inverted V type so as to avoid dust settling on the edges or in the groove. The l>ase is of solid brass, giving a low centre of gravity, and the whole instrument is of solid and compact construction, able to stand any ordinary hard usage. Gilt and lacquered throughout. Balance is supplied in box with parts fitted for portability, but it can be supplied also in glass case at an extra charge. £17 10 0 1749 1750 1749 1750 Balance, Oertling's No. 15 Portable Assay, steel knife edges on agate planes, to carry 2 grammes in each pan, and turn distinctly with o.i milligramme. Outside dimensions of case, 8 in. square by 2 in. deep Balance, Oertling's No. 16 Portable Assay, to carry 2 grammes in each pan, and turn with o.i milligramme ; fitted with double rider-slide, levels, and three levelling screws, steel knife edges on agate planes ; outside dimensions of case, 8 in. square by 2 in. deep Leather Case, with shoulder strap, to carry above balance . . . . . . extra £7 10 0 £11 0 £1 10 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. : ^L 359 cr BAIRD &TXTLOCK. (LONDON) LTD. . -^-«=a. tiff, 1751 1751° Balance, Oertling's No. 17 Portable Assay, with 5-in. horizontal beam with agate knife edges, centre and ends working on agate bearings ; to carry 2 grammes in each pan, and turn with 0.05 milligramme ; fitted with double rider-slide, levels, and levelling screws ; outside dimensions of case, 8 in. square by 2 in. deep . . . . . . £15 0 Fitted in leather case with shoulder strap .. .. .. .. .. extra £1 10 1752 1752" Balance H, Oertling's Bullion, for weighing coin, constructed with knife edges working on agate, to carry 200 oz. in each pan .. .. .. .. £18 18 0 CROSS STREET- HATTOTST GARDEN, E-C RAIRD &.TATLOCK (LONDON) LTD. 1754 1754« Balance B. Oertling's Bullion, with 30-in. beam, to carry 1,200 oz. in each pan, and turn with $ grain . . . . . . £37 10 0 1755 17551 Balance C, Oertling's Bullion, with 3O-in. beam, to carry 1,000 oz. in each pan, and turn with i grain ; centre knife edge working on agate planes . . . . . . £32 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK: (LONDON) LTD. 1756 1756" Balance (Fig. 1755, page 361), packed for export in a zinc-lined case, of which the dimensions are Go by 24 by 19 in., and the gross weight about 300 Ibs., or 136 kilos . . £35 0 0 1757 1758 1757" Balance for taking Specific Gravities (Westphal's), with riders, plummet thermometer, and forceps, in polished box with directions 1758U Balance for taking Specific Gravities, with Mohr's modifications for solids and fluids, with plummet thermometer and set of riders DIRECTIONS FOR USE. After the instrument is mounted and the beam rests in equilibrium, the glass plummet which contains the thermometer is suspended from the right-hand knife edge of the divided beam and on the double-arm scale counter- poised by the weight included. The absolute weight of the plummet including platinum wire amounts to 15 grammes, and the displacement of its volume is equal to 5 grammes of distilled water at 15° C., at which normal temperature these weighings are based ; accordingly the unit rider is 5 grammes, and the smaller ones 0.5, 0.05, and 0.005 gramme. To use the balance, the larger rider is put on the same hook with the plummet, and the latter immersed into distilled water until the equilibrium is restored ; in this position the platinum wire twisted around the top of the plummet is always below the surface of the water. If the liquid is lighter than distilled water, i.e., lighter than i°. the large rider must be placed somewhere on the divided beam, where it will again produce equili- brium ; but when this occurs at some point between two notches on the beam, this rider must be placed on the notch of lower value of the two between which it rests, and then the next size rider applied to determine the difference. Should the position of this second rider also fall between two notches, the third and eventually the fourth or smallest is brought into use in the same manner as described above with the largest rider. If it happens that two riders come to rest at the same notch, the smaller is suspended from the larger one. In this way the specific gravity of a liquid can be read off down to the fourth decimal place from the divided beam. If a liquid heavier than distilled water is tested, the process is the same as described above, with the addition that one of the large riders is always hung from the hook with the plummet, while the other riders cross the beam at the proper points. It is obvious that all plummets have the same weight and volume ; broken plummets and lost riders can therefore te replaced without it. being necessary to return the balance. £1 £2 7 6 0 0 -CROSS STREET • HATTOTST GARDETST, E'C BAIRD &.TATLOCK. (LONDON) LTD. 1759 1760 17591 Sartorius' Mai nice for taking Specific Gravities, on adjustable stand, with levelling screws, and Rumann's float, displacing 10 cubic centimetres of water, all fitted in leather covered case. The riders are arranged for four places of decimals, weighing 10, I, ^, 1760U Sartorius' Specific Gravity Balance, with pan for weights, suitable for taking the specific gravity of solids and liquids o • Jin £326 £400 JlA 1761 1762' 1763 1761 1762 1763 Balance, Becker's, for Specific Gravities, with equal arms for liquids and solids, new arrangement for raising the beam 8 centimetres by means of a cogwheel movement, through which a total height of 28 centimetres can be obtained. Provided with Rumann's patent thermometer plummet, two pans for analytical work, two sets of riders, set screws, and plummet. Capacity 50 grammes in each pan, sensible to i milli- gramme with its full charge Thermometer Plummet, with platinum wire and suspension hook, for Specific Gravity Balances, Nos. 1757, 1758, and 1761 Rider Weights for Balances Nos. 1757, 1758, and 1761, two each, 5, .5, .05, .005 grammes. Per set of eight £250 £066 £026 [CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK. (LOM)ON) LTD, 1764 1764U Specific Gravity Balance for mineralogical purpose, for taking the specific gravity of samples of ore, etc. The balance is easily portable and is supplied complete in case as figured .. .. .. .. ... .. .. .. £2 10 100 grammes. 5 milligrammes. £100 1767U Paper Balance, with silvered scale, and adjusted to show on weighing one sheet the weight of 1,000, 500, or 480 sheets 1765 1765' Balance, Becker's, on French polished box with drawer. To carry Sensitive to Price 1766U Balance or Prescription Scale, Becker's, on French polished box with drawer, eccentric for lifting, bows, and movable pans, set screws and plummet. To carry . . . . . . 50 100 250 grammes. Sensitive to . . . . i i 2 milligrammes. Price £1 10 0 £1 17 0 £2 19 0 BAIRD &TATLOCK. (LONDON) LTD. 1768 1770 A 1772 1771 1768U Pocket Balance, in French polished mahogany box, for a charge up to 10 grammes in each pan, sensible to 2 milligrammes. With set of weights 5 grammes down to 2 milli- grammes . . . . . . . . . . . . . . . . .. 1769U Pocket Balance, same as above, for a charge up to 100 grammes in each pan, and sensible to 5 milligrammes. With set of weights 50 grammes down to 5 milligrammes . . . . 1770" Lever Balances, to weigh 50 grammes 1771" Lever Balance, with silver-plated scale, graduated to grammes — To carry . . . . . . . . . . 100 Price .. .. ..8/6 each, 1/2; per doz. 250 grammes. 10/6 each. 1772' Diamond Balance, in French polished mahogany box, can be charged up to 64 carats in each pan, sensible to ^ carat, with its full charge. With set of weights 64 carats down to T'T carat . . . . . . . . . . ' M772" Micro-Balance, as devised by Prof. Dr. W. Nernst DESCRIPTION OF BALANCE. A very fine quartz thread about 5 centimetres long is placed horizontally between the prongs ot a brass fork supported vertically on a pillar 16 centimetres high. Crosswise on it rests the capillary glass, 30 centimetres long, 0.5 millimetres diameter, which constitutes the balance beam ; this is fixed, by means of sodium silicate, to the quartz thread. On the shorter arm of lever, which is about 9 centimetres long, a platinum hook is fused ; on this the pan can be suspended. The long arm of lever is bent downwards at right angles, and tapers into a very fine thread, over a graduated glass scale, which is divided into 0.5 millimetres. By observing through a telescope under a good light, fa of each division is discernible. A brass fork is fitted to act as a support. On the left arm of the balance a platinum cursor is attached by means of sodium silicate ; this is to counterpoise the scale pan. This form of cursor has been devised to afford the required stability to the balance, without reducing its delicacy more than is desirable for the measurement to be effected. The small platinum pan weighs, including the sus- pension thread about 20 milligrammes. For weighing small crystals or for weights, a disc is supplied ; this is made of platinum foil 0.8 centimetres diameter by 0.015 millimetres thick ; for decimal weighings a small capsule is used of the same thickness as the round plate. The balance is supplied in a glass case, mounted on slate sole, fitted with three thumbscrews. By regulating these screws one can easily adjust the balance on the zero point. The balance is designed to weigh up to 2 milligrammes, sensitiveness ,-^5 to rfas part of a milligramme. Each balance is supplied with directions showing how to mount same ready for use. £109 £1 6 £0 13 0 0 £120 £750 BAIRD &TATLOCK (LONDON) LTD. 1773 1773" Balance, Jolly's Spring, with a series of springs of various strengths, and graduated mirror scale. Mounted on tripod base with levelling screws This balance is used for — (a) Determination of the weight of small bodies. (b) ,, ,, specific weight of solids. (c) ,, ,, specific weight of fluids. The balance consists of a spring suspended from the top of a sliding support ; the spring carries on its lower end a scale-pan and an index mark above the latter. The support has a mirror millimetre-scale on which the position of the mark can be read without parallactic error. A small glass pan and a solid glass body are to be used as described in the following instructions. A small table to carry a glass vessel filled with water or other fluid slides on the stand, and may be fixed in any desired height. Levelling screws serve to bring the instrument into a vertical position. The principle of the balance is founded on the law of elasticity that (within certain limits) the elongation of a spring is proportionate to its load. To prevent these limits being exceeded, and to enable the instrument to be used for different loads, a number of springs are supplied with each balance, each spring carrying up to 2, 6, and 10 grammes. (a) Determination of Absolute Weight. Let the index mark indicate any point " m " of the scale ; if a body is placed in the pan the mark will indicate another point "n." Then « — m is the absolute weight, measured in divisions of the scale. Should the body have a weight of 5 grammes and stretch the spring f. i. from 150 to 600 millimetres, then an elongation of 450 millimetres corresponds to a weight of 5 grammes 45 „ „ ,. 0.5 4-5 ,. °-°5 ., for the same spring. (b) Determination of Specific Weight of Solids. Fix the small glass pan below the metal pan ; place a glass vessel filled with distilled water on the sliding table, and during the whole experiment let the glass pan dip into the water, but take care that it does not touch the sides or bottom of the vessel. First determine the absolute weight of the body (which must be placed in the upper metal pan) as described above = n — n>. Then put the body into the glass pan (dipping into water); the table with the glass vessel must then be raised to a point " p." £250 14- -CROSS STREET • HATTON GARDEN, E- C 366 BAIRD & TATLOCK (LONDON) LTD. Then «- pis the loss ol weight in water, and n_ . is the specific weight of the body. For instance : First reading (m) =150 millimetres, second reading (n) =600 ,, absolute weight (n - m) =600- 150=450, third reading (p) =510 millimetres, loss of weight in water (« - p) =600— 510=90, n — m 450 specific weight — = — = 5. -p 90 (c) Determination of Specific Weight of Fluids. Remove both pans and fix the solid glass body to the spring. Determine for the body after the above- flescribeil method — the loss of weight in water, which may be = 90, ,, ,, the fluid to be examined, which may be = 108. 1 08 Then — - = 1.2 is the specific weight of the fluid. 1774 1775 1774L Balances, Hand Scales, brass beam and horn pans, suspended by silk cord — Length of beam . . . . 10 13 17 19 25 30 centimetres. Diameter of pans . . - • 3i 5 7 8 io£ 13^ Price each .. ..2/6 3/- 3/6 4/- 6/- 8/- 1775U Dispensing Scales, in oak boxes (with weights, 2 drachms to i grain) Length of beam . . . . . . 5 6 8 in. A. With brass pans . . . . . . 4/6 4/9 5/6 B. With glass pans . . . . . . 5/6 5/9 7/- 1776 1776" Balances, Beranger's principle, round brass movable pans. Diameter of pans To weigh Price On stained walnut box, with marble top, and two i 211- 7 2 24/- 8 in. 5 kilos. 28/- (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 367 BAIRD &TmOCK (LONDON) LTD. Spring Balances. 1777 1779 1783 1777" Spring Balances. Graduated in grammes, and provided with a hook and ring for suspension, flat brass dial. Jg. kilo up to 5 9d. 8/6 1778U Spring Balances, similar to above. 10 12 kilos. 3/3 5/9 each. 36/- 65/- dozen. Capacity Reading to . . 50 2\ 6d. 100 5 lOd. 100 2/9 250 10 2/6 500 10 1,000 gms. 10 gms. 6/6 each. 1779" Spring Balances, with circular brass case. kilo up to 1780" Spring Balances as above. Capacity Reading to . . 358 kilos. 2/- 2/6 3/3 each. 22/- 27/- 36/- per doz. 50 100 250 gms. 2\ i 10 gms. 2/2 4/6 4/9 each. 1781" Spring Balances, graduated in pounds and divisions of a pound, with brass scale and hook, as No. 1777. 2 Ib. by £ oz. 4 Ib. by \ oz. 6 Ib. by i oz. 8 Ib. by i oz. 10 Ib. by i oz. 12 Ib. by 5/9 5/9 5/- 5/9 6/6 9/- 1782" Spring Balances. As above, but with circular brass case as Fig. 1779. 2 Ib. by i oz. 4 Ib. by i oz. 8 Ib. by 2 oz. 10 Ib. by 4 oz. 20 Ib. b- 2/9 3/6 4/- 2/9 I OZ. each. 1783U Pedestal Spring Balances. With graduations on circular dial. A. 5 kilo 20 gr. 5 in. dial . . . . B. 10 „ 50 „ C. 15 „ 50 „ D. 20 „ 50 ,, E. 25 „ 50 „ 47- each 4 oz. each. £076 £076 £086 £0 12 0 £0 13 0 CROSS STREET : HATTOTST GARDEN, E-C 368 BAIRD &TATLOCK. (LOM)ON) LTD. 17841 Pedestal Spring Balances. Cast iron stand, enamelled round dial, as Fig. 1783. A. 7 Ibs. to J oz. 5 in. dial B. 14 £090 £090 £0 15 0 £0 10 6 £0 16 6 £1 12 0 1785 1786 1787 1785" Dispensing Balance, fine quality, brass beam, Board of Trade pattern, sensitive to ^ grain, continuous knife edges, loose steels in bows, giving freedom of action. Sight hole cheek, leaving indicating needle clear. Brass lever pillar, folding brass arm, brass weight pan and chains, removable glass pan. One spare pan. Solid mahogany box, complete with weights . . 1786' Balance, on polished mahogany box with drawer, and two glass pans. Complete with weights, i set J to 6 grains and i set from \ scruple to 2 drachms 1787" Balance, on polished stand with drawer, and glass pans. Complete with weights, as Fig*. 1786 £0 16 6 £126 £150 1788' 1788 1789-1790 Balance, for weighing samples, japanned and gilt, with steel knife edges and bearings. To weigh . . . . . . . . 7 14 28 Ibs. Price 17/6 19/6 25/- Triangular Glass Dessicators, suitable for placing inside balance cases. 1789' Large, 3^ bv 2j in. high . . 1790" Small, 2 by"ij in. high £0 1 3 £0 1 0 :HEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 369 BAIRD (ScTATLOCK (LONDON) LTD, Weights -Chemical, Assay, and Physical. 1791-1800 1801-1803 Weights, Analytical, best quality, in polished mahogany case, velvet lined. Fractions of a gramme in platinum, weights of 1 gramme and upwards gilt. 1791" 50 to .001 gramme 1792' 100 to .001 gramme .. 1793" 200 to .001 gramme 1794" 500 to .001 gramme Weights, Analytical, best quality, in polished mahogany case, velvet lined, weights of i gramme and upwards gilt. Fractions of a gramme in aluminium. 1795" 50 to .001 gramme 1796" 100 to .001 gramme Weights, Analytical, as above, best quality, but weights from 1 gramme upwards, platinum plated instead of gilt. Fractions of gramme in platinum. 1797' 50 to .001 gramme 1798l: 100 to .001 gramme Weights, Analytical, in polished mahogany case, velvet lined. Weights 1 gramme upwards brass, lacquered. Fractions of a gramme in platinum (as Figs. 1791-1800). 1799" 50 to .001 gramme 1800" 100 to .001 gramme Weights, Analytical, Sartorius' Make, in velvet lined mahogany case, the decigramme and centigramme weights are of platinum and the milligramme weights of aluminium, weights from 1 gramme upwards gilt. 1801" 50 to .001 gramme 1802U loo to .001 gramme 1803" 200 to .001 gramme £1 £1 13 £2 5 £2 18 £1 5 £1 10 £1 £1 5 9 £1 12 £1 17 £2 10 CROSS STREET • HATTOTST GARDEN, E- C BAIRD &TATLOCK (LONDON) LTD. A1803-C1803 A 1803" Weights, Standard Quality for Research Work, in sets, weights from 1 gramme upwards of rock crystal, smaller weights of platinum, in polished mahogany box, velvet lined. Set, 20, 20, 10, 5, 2, 2, i grammes, .5 to .001 grm. in platinum . . £650 B1803' Weights as above. Set, 50, 20, 20, 10, 5, 2, 2, i grammes, .5 to .001 grm. in platinum £900 c!803u Weights as above. Set, 100, 50, 20, 20, 10, 5, 2, 2, i grammes, .5 to .001 grm. in platinum £11 10 0 X T D1803-E1803 nl803u Weights, Paul Bunge's, in sets, weights i gramme and upwards gilt, fractions of aluminium, spiral form, in polished mahogany box. Set, 50 to .001 grammes . . . . £150 El 803" Weights as above. Set, 100 to .001 grammes £1 10 0 371 2 B BAIRD &TATLOCK (LONDON) LTD. •CERTIFICATE- OF- EXAMINATIOPi OF Sc T or G«A M WftsH rs FOR BAIRD & TATLOCK 1804-1805 Weights, Standard Analytical, in polished mahogany case, velvet lined. Fractions of a gramme in platinum, weights of 1 gramme and upwards gilt, with National Physical Laboratory Certificate. 1804" 50 to .001 gramme 1805" 100 to .001 gramme £286 £2 13 6 1806 1806° Weights, Analytical, medium quality in polished mahogany case, inside of case lined with white celluloid with fractional weights in celluloid tray with metal rim, removable. Weights 50 to i gramme gilt, 0.5 to .001 gramme of German silver . . . . per set 1807" Weights, Analytical, medium quality as above but weights 50 to i gramme nickel plated, 0.5 to .001 gramme of German silver . . . . . . . . . . per set £0 17 6 £0 14 6 CROSS STREET • HATTOTST GARDEN, E-C 372 BAIRD &TATLOCK (LONDON) LTD. 1808-1816 1817-1818 Oertling's Gramme Weights, in polished mahogany box, with riders and forceps. Weights of 1 gramme and upwards polished brass. Fractions of a gramme in platinised German silver. 1808' 50 to .001 gramme .. .. 1 809" 100 to .001 gramme Oertling's Gramme Weights in polished mahogany box with rider and forceps. Weights of 1 gramme and upwards polished brass. Fractions of a gramme in platinum. 18121 50 to .001 gramme 1813U 100 to .001 gramme 1814U 200 to .001 gramme 1815" 500 to .001 gramme 1816" 1,000 to .001 gramme Oertling's Grain Weights, in polished mahogany box, with riders and forceps. Fraction? of a gramme in German silver. 1817" 1,000 to .01 grain 1818U 10,000 to .01 grain 1819-1821 1819U Becker's Weights, 500 milligramme piece and down to i milligramme, in box . . 1820" Becker's Weights, 1,000 „ „ i „ „ 1821" Becker's Weights, Set of Platinum Weights, i gramme down to i milligramme, in box £1 15 0 £2 5 0 £2 10 0 £3 0 0 £3 5 0 £3 18 0 £4 10 0 £1 15 0 £3 12 0 £060 £070 £170 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD & TATLOCK (LONDON) LTD. 1822-1829 1827 Becker's Gramme Weights, in polished mahogany boxes, lined with velvet, every piece fitted separately ; the fractions of the gramme are made of aluminium, and are covered by glass slab. 1822" 20 gramme piece and down to i milligramme 1823" 50 „ i 1824" 100 „ „ „ „ i 1825" 200 i 1826U 500 ,,,,,,,,1,, 1827" i kilogramme piece and down to i milligramme Becker's Grain Weights, in polished mahogany boxes, lined with velvet, every brass piece fitted separately ; 10 grains and downwards are made of aluminium, and are covered by glass slab (Fig. 1822-1829). 1828U 1,000 grains down to Tgff grain .... .... 1829" 10,000 . . . . - . . ' £0 10 £0 12 £0 13 £0 15 £0 19 £1 3 £0 12 £0 19 1830° Set of Aluminium Grain Weights 1830 5, 2, 2, i 5, 2, 2, i 5, 2, 2, i (as in sets Nos. grams tenths hundredths 1828 and 1829) £047 14 -CROSS STREET • HATTQTST GARDEN, E-C 374 BAIRD &TATLOCK (LONDON) LTD. 1831-1833 Oertling's Gramme Weights, in mahogany boxes. Weights of 1 gramme and upwards polished brass. Fractions in platinised German silver. 1831'; i kilogramme to I milligramme, with riders 1832U 500 grammes to i milligramme, with rideis 1833" i kilogramme to 100 grammes £3 15 £33 £2 10 0 0 0 BULLION AND ASSAY WEIGHTS. 1834-1837 1834U Weights, Oertling's Troy, for bullion balances, in polished mahogany cases, set of 500, 300, 200, 100, 50, 30, 20, 10, 5, 3, 2, i oz. (with 0.5, 0.3, 0.2, o.i, 0.05, 0.03, 0.02, o.oi, 0.005, 0-003, 0.002, o.ooi, in small box) . . . . . . . . . . £20 0 0 1835" Set of 300 oz. to o.ooi, as above . . . . . . . . £16 0 0 1836° „ 200 oz. „ o.ooi, „ . . £12 10 0 1837" „ 100 oz. „ o.ooi, . . £10 10 0 375 BAIRD &TATLOCK (LONDON) LTD. 1838 1839 1838" Weights, brass troy cup form, in sets. o.i to 5 oz. 10 or.. 20 oz. 50 oz. troy. 7/- 9/- 14/- 32/- per set. 1839U Oertling's Assay Weights, 10 grains and its subdivisions in 1,000 parts, in platina, for assaying of silver 1840" Oertling's Assay Weights, i gramme and its subdivisions in 1,000 parts, in platina, for assaying of silver, as Fig. 1839 £250 £2 15 0 1841 1841" Oertling's Assay Weights, J gramme and its subdivisions in 1,000 parts for assaying of gold .. .. .. .. .. !. .. .. .. £1 10 0 1842 1842U Oertling's Assay Ton Weights, fitted in mahogany block with lid, 4 to 0.05 A.T. per set £1 15 0 A B C D Either: i AT=2g.i66 grammes ; i AT=32.666 grammes ; i AT= 291 f grains ; i AT ="326! grains. 1843" Becker's Assay Ton Weights, of 4 " A.T." down to ^V " A.T." .. .. .. £0 14 0 The Assay Ton Weights have been introduced by Prof. Dr. C. K. Chandler, of the School of Mines, Columbia College, New York, where they are now in use for convenience in the assay of ores. The weight denominated by Dr. Chandler I " A.T." equals 29.1666 grammes, and contains consequently as many milligrammes as there are troy ounces in a ton avoirdupois of 2,000 Ibs. Therefore if i " A.T." of ore assays i milligramme, the ton contains I ounce troy. CRO^S STRET • HATTCTK GARDEN, E- C BAIR-D &TATLOCK (LONDON) LTD. PHYSICAL WEIGHTS. 1844-1846 1847-1852 Weights, brass, in polished mahogany box with hinged lid, forceps, and glass plate to cover small weights, each piece fitted separately, fractions .5 to .001 grammes in German silver. 18441 50 to .001 gramme 1845" 100 to .001 gramme 1846" 200 to .001 gramme Weights, brass, in polished box with forceps, fractions .5 to .001 grammes in German silver 20 to .001 gramme 50 to .001 gramme 100 to .001 gramme 200 to .001 gramme 500 to .001 gramme 1847' 1848' 1849' 1850" 1851' 1852" 1,000 to .001 gramme £0 £0 £0 12 £0 £0 £0 £0 £0 15 £0 19 1856-B1857 1853-1855 Weights, brass, in block, with glass covering for fractions, and pair forceps 1853" 20 to .001 gramme 1854U 50 to .001 gramme 1855" 100 to .001 gramme Weights, brass, in wooden block without cover. 1856" 500 to i gramme 1857" 1,000 to i gramme A1857" 2,000 to i gramme Bl857u 5,000 to i gramme £030 £040 £050 £076 £096 £0 19 6 £1 18 0 1EMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. 1858 1858L Weights, in polished hinged box with cover. I to 100 grammes. 500 grammes. 4/6 9/- 1,000 grammes. 14/- per set. 1859-1860 Brass Weights, in polished walnut case, velvet lined, with lifter and forceps. 1859U i to 2,000 grammes I860" i to 5,000 grammes £200 £300 CROSS STREET • HATTOTST GARDETST, E-C 373 1861 1862 1861" Weights, suitable for students' use, in polished mahogany cases, i gramme and upwards" in brass, .5 to .001 gramme in aluminium, with glass cover for decimal weights, and forceps. From .001 to . . 50 100 200 500 1,000 grammes. Price 9/6 12/- 16/6 19/6 25/- per set. 1862" Weights, 500 milligrammes to i milligramme, in wooden box with sliding lid. per set, 1/6 ; per doz. sets £0 17 6 1863 18631' Weights, gilt, best quality, for analytical work, single, as in sets Nos. 1791-1800. i 2 5 10 20 50 100 grammes. Price .. ..I/- 1/1 1/4 1/6 2/- 2/6 3/6 each. JOO M C 1864 1866 18641 Weights, platinum, first quality, as in sets Nos. 1791-1794, &c. .5 .2 .1 .05 .02 .01 .005 .002 6/- 2/8 1/8 I/- 9d. 6d. 4d. 4d. The prices of all platinum weights are liable to alteration according to market value of platinum. .001 grammes. 4d. each. 1865" Oertling's Analytical Single Weights, platinised German silver, as in sets Nos. 1808-1809. A. 100 60 30 20 10 6321 .6 .3 .2 .1 .06 .03 .02 .01 grains. 2/6 2/3 1/8 I/- 8d. 4d. each. B. 5 2 i .5 .2 .1 .05 .02 .01 .005 .002 .001 grammes. 2/- 1/6 1/3 1/6 ~T]3 ~fJT~ 4d. each. 18661' Weights, Becker's aluminium, as in sets Nos. 1822-1827. .5 .2 .1 .05 .02 .01 4d. 4d. 4d. 4d. 4d. 4d. 3/6 3/6 3/6 3/6 3/6 3/6 1867" Watch Glasses, carefully tared, 2 J in. .005 .002 .001 grammes. 4d. 4d. 4d. each. 3/6 3/6 3/6 per dozen. . . per pair £013 BAIRD &TATLOCK. (LONDON) LTD. 1868 1868" Riders for Balances No. i 2 3 4 5 6 Oert ling's Oertling's As in Sets Becker's Bunge's Bunge's. 1791-1803 Weight Price .01 6d. .001 6d. .01 4d. .012 9d. •05 9d. .005 gramme. 6d. each 1869 1869" Weights, single, polished brass, ordinary quality, as Figs. 1844-1855. i 2 5 10 20 50 100 200 5°° grammes. Price I/- 1/3 1/9 2/- 3/6 5/6 9/- 15/- 27/- per doz. 1,000 2,000 5,000 10,000 grammes. 4/- 8/6 "17/6 31/- each. 1870 1870" Weights, German silver, .5 to .001 grammes, as in sets Nos. 1844-1855 . . per doz. £0 1871 1871" Weights, flat brass, in sets. From J oz. to \ Ib. Price 3/- i 4/6 1872" Weights, flat brass, single, Fig. 1871. J i i 2 4 Price 2d. 2d. 3d. 4d. 7d. 8oz. 4 Ibs. 13/6 1247 Ibs. 1/10 3/6 6/6 10/6 each. CROSS STREET • HATTCTNT GARDETST, E- C BAIRD &.TATLOCK (LONDON) LTD. 1873 1874 1875 1873" Iron Bar Weights, for use with rough Balances. J to 4 7 Price per set . . • • 2/6 3/6 1874" Iron Kilogramme Weights, with ring. i 2 5 lOd. 1/1 3/6 9/- 12/6 40/- i i i 1-875" Kilogramme Weights, iron cylindrical or hexagonal with ring for lifting. Weight & i 4 I 2 5 2d. 3d. 6d. 9d. I/- 2/3 1876' Weights, flat iron, unstamped, in sets. 4 oz. to i Ib. 2 Ibs. I/- 1/8 1876 14 Ibs. 5/6 10 kilos 6/9 each. 78/- per doz. 10 kilos. 4/- each. 7 Ibs. 4/- per set. 18771 Horn Scale Pans, accurately adjusted in pairs, for Balances. Diameter ..5 6 8 9^ ni 15 Per pair .. 1/2 1/3 1/9 2/6 3/- 5/6 17 6/3 20 centimetres. 6/9 1878 1878— Stool in use. 1879 1878" Stools of polished mahogany for use with Physical Balances for taking specific gravities. For 100 250 500 gramme balances. I/- 1/3 1/6 each. ll/- 14 f- 17 /- per doz. 1879U Porcelain Plate, with depressions for small weights, for placing inside balance case each, 1/3 ; per doz. 1880" Celluloid Plate, with depressions for weights .5 to .001 gramme each, I/- ; per doz. £0 14 6 £0 11 6 BALANCES GLEANED, REPAIRED, AND CAREFULLY ADJUSTED IN OUR OWN WORKSHOPS. 381 BAIRD &TATLOCK (LOM)ON) LTD. 382 Section VI. ENERAL CHEMICAL APPARATUS Basins, Beakers, etc. Bottles. Condensers Drying Ovens and Water Baths Furnaces Graduated Apparatus Kjeldhal's Apparatus Platinum Apparatus Retorts Silica Apparatus Stands. Filters, Retorts, etc. Stills and Condensers Pages. 371-398 408-422 433 441 477-502 543-573 593-607 686-689 45.3-460 719-722 461^473 734-747 437-441 Laboratories completely equipped. Estimates given, upon receipt of ground plan and full particulars. 14. CROSS STREET. HATTON GARDEN, EC BAIRD &TMLOCK (LONDON) LTD. The following are the different Sections in our Catalogue. Those marked * are also printed separately. Section No. 1.* Laboratory Fittings 2.* Bacteriological Apparatus Chemical Physiology Apparatus Microscopes and Microscopical Accessories Balances and Weights Chemical Apparatus Botanical Apparatus Gas Analysis Apparatus Milk Analysis Apparatus Refractometers Oil Analysis Apparatus Water Analysis Apparatus Cement Testing Apparatus Leather Testing Apparatus Paper Testing Apparatus Physico Chemical Apparatus Pyrometers Calorimeters Seed and Soil Analysis Apparatus Spectroscopes and Polariscopes Volumetric Apparatus Anatomical Models Meteorological Apparatus Assay Apparatus 3. 4.* 5.* 6.* 7.* 8. 9." 10. II." 12. 13. 14. 15. 16. 17.* 18.* 19.* 20.* 21. 22. 23. 24.* 25.* Chemicals Pages Nos. 14.56 57.161 162.192 193*. 320 321.382 383.816 817.842 843 . 886 887.894 895 . 902 903 - 926 927.933 934^946 947.949 950-951 952.976 977.1006 1007.1022 1023.1042 1043.1078 1079.1087 1088.1105 1106.1124 1125.1172 1187.1246 CROSS STREET- HATTON GARDEN, E-C cr BAIRD &TATLOCK (LONDON) LTD, Sr, SECTION No. 6. Chemical and General Apparatus. 1900 1901 1902 1903 1900 Adapters, small, for Liebig's condensers, straight or bent 1901 Adapters, bent form, of heavy Bohemian glass. Length . . . . . . 8 by ij 10 by 1903A each £004 Each 6d. 1902 Adapters, straight form, of heavy Bohemian glass. Length . . . . . . 10 by i Each 8d. 9d. 12 by i 9d. 12 by 2 in. I/- 14 by 2 in. lOd. 1903s Anemometer, Fletcher's, for measuring speed of flue gases. Price, in polished mahogany case This is a convenient apparatus for measuring the speed of draught in the flues of chemical works, where any fine mechanism would soon be ruined. It is based upon the movement of a column of ether in a U tube (described in " Lunge's Sulphuric Acid and Alkali," 1,330 ; in, 361). Illustration shows this in the simpler form, leaving out the microscopes, which are quite unnecessary for reading the divisions of the scale or vernier. The ends of the glass tubes, (a 6), should be placed rather less than one-sixth of the diameter of the flue from its inner wall. The straight end of (a) ought to be as exactly parallel as possible to the direction of the draughts ; the end of (fr) ought to be exactly at a right angle to this, and so that the current would blow right into it. Without this precaution a mistake is made, which is avoided by the arrangement shown in Fig. igo3A, and proposed by Hurter, viz., employ- ing tubes with ends bent in opposite directions. The tubes (a b) communicate with the ether tube (cd>, , the draught causes the ether to rise in (a) by aspiration, to fall in (6) by the pressure of the air blowing into the tube. The difference of level between (c) and (d) is read off by means of the scale and vernier. When the sliding disc («) is turned 180°, the currents are reversed. There will now be a difference of levels in the opposite direction, but equal in amount to the first, if the observation is correct. The sum of these two differences is meant by the " Anemometer Readings " in the tables. (See " Alkali Makers' Handbook," Lunge and Hurter, p. 87.) £3 10 0 1904 1904U Anemometer, inclined pattern, with levelling screws to stand, sliding verniers, and scale complete in portable case £330 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 383 BAIRD &T&TLOCK (LONDON) LTD. 1905 1906 1905 Arsenic Apparatus, Marsh's, complete on mahogany stand, with brass stopcock and jet £056 1906 Arsenic Apparatus, Tyrers (See Chemist and Druggist, 23rd March, 1901, p. 493-) 1907 Arsenic Apparatus, with drying tube, testing tube of Jena combustion ^lass. 1908 Testing Tubes of Jena glass, for above 1909 1909 Arsenic Apparatus, Kirkby-Gutzeit Directions (or using the Kirkby-Gutzeit Apparatus for Arsenic Testing. Dissolve 2, 5, or 10 grammes of the substance to be tested in about 10 c.c. of water in the flask, add 10 c.c. of pure arsenic-free H,SO4, and cool the mixture under the tap. Half fill the absorption bulbs with 5 % lead acetate solution. Tie firmly on to the thistle head of the apparatus a cap made of filter paper which has been moistened with 3 drops of a 5 % solution of mercuric chloride and dried. Then place 7 grammes of arsenic-free zinc in the flask and fix the upper half of the apparatus in position. If there is no evolution of hydrogen, water must be added to the contents of the' flask in quantities of not more than one c.c. at a time, until the gas is evolved at the rate of about one bubble per second. Further small additions of water should be made to maintain this rate of evolution, until all the zinc is dissolved, this usually taking from two to three hours. The depth of the stain produced on the cap of filter paper is then compared with stains obtained by using known quantities of arsenic in the apparatus. These standard stains are obtained by mixing 10 c.c. water and 10 c.c. cone. HSSO4 in the flask, cooling the mixture, and then adding a small and carefully measured quantity (2, 3 or 5 c.c.) of the dilute standard arsenious acid solution. Then 7 grammes of zinc are added, and the upper half of the apparatus, fitted with a dried cap of mercuric chloride paper, is placed in position. If to grammes of the substance have been taken, and have given a stain equal in intensity to that obtained from x c.c. of dilute standard arsenious acid solution, the substance contains x parts per million of As,O3. Two Standard Arsenic Solutions are prepared : I. Strong : by dissolving I gramme, As,Oa in a litre of water. II. Dilute : by diluting 10 c.c. of the strong solution to one litre (o.ooooi grammes, As,O, per c.c.). In order to obtain stains useful for estimation purposes it is desirable that they should not be more intense than that given by 0.00005 grammes As,O8 (=* 5 c.c. of the dilute solution). £046 14 -CROSS STREET • HATTCnST GARDEN, E-C BAIRD &TATLOCK (LONDON) LTD. . 1910 1910" Arsenic Apparatus, for the estimation of arsenic by electrolysis, standard pattern as used in the Inland Revenue Laboratory. (For description see/ourna/af Chemical Society , August, I903-) Price of glass parts, with platinum wire connection of 18 B.W.G. as used at the Govern- ment Laboratory, porous pot, and Bunsen burner Platinum electrodes extra, weight of the pair about i oz. troy, present price 218/- per oz. troy. (This apparatus requires a current of 8 volts, 5 amperes.) £1 15 0 1911 1913 1914 1911 Arsenic Apparatus, standard pattern, zinc and acid method, with Bunsen burner 1915 £090 1912 Arsenic Tubes of Jena Combustion Glass, standard pattern G., Fig. 1910, for use with apparatus Nos. 1910 and 1911 per doz., 1/3 ; per gross £0 14 6 1913 Arsenic Tubes, Clark's, with bulb, of Jena combustion glass, per doz., 9d. : per gross £086 1914 Arsenic Tubes, plain, of Jena combustion glass. A. 3 in. by f in. B. 2 in. by J in. 1915 Balloons, gold-beater skin. 18 per doz., 8d. ; per gross £070 5d. ; „ £046 27 32 36 42 48 in. circumference 1/6 2/- 2/6 3/6 4/6 each. iflCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 385 BAIRD &TATLOCK (LONDON) LTD. 1916 Balloons, collodion. 1917 Balloons, best soft indiarubber. 4 lOd. 6 I/- 2 2d. 1/10 8 II 14 in. length when flat. 1/6 2f- 3/- each. 3 4d. 3/6 6d. each. 5/- perdoz. ""• "J 1918 1919 1920 1921 1922 1918s 1919' 1920s 1921s 1922s Barometer, Bunsen's, syphon tube, graduated into millimetres, filled with mercury, and mounted on mahogany stand, with mirror back to avoid parallax when reading . . £1 Barometer, Bunsen's syphon, with plain tube and sliding millimetre scale on polished mahogany board for direct reading, suitable for school use . . . . . . £1 Barometer, designed by Mr. Gee, with boxwood millimetre scale and two sliding points . . £0 Syphon Barometer, consisting of an ungraduated Bunsen syphon tube, filled with mercury and mounted on a polished mahogany board fitted with a sliding millimetre scale for direct reading. The necessary adjustments and readings are made on the scale by means of two sliding indexes fitted with cross wires, and mirror backings at the upper and lower surfaces of the mercury column. This barometer is of thoroughly reliable construction, and as the height of the column can be read with fair accuracy to .1 mm., it is suitable for all ordinary purposes. The tube used in the instrument is provided with an air-trap, and fitted with boxwood scale . . . . . . . . . . . . ..£112 Barometer, with ivory scale, sliding vernier, thermometer, and adjusting screw on polished oak frame ...... . . £1 1 CROSS STREET • HATTOW GARDEN, E-C 386 BAIRD &TATLOCK (LONDON) LTD. 1924-5 Cistern of Fortin's Barometer. 1926-1928 1929-1930 1924 Barometer Tube, Bunsen's, with air trap, without mercury, graduated into millimetres . . £060 1925 Barometer Tube, Bunsen's, filled with mercury, and graduated into millimetres . . £0 16 6 1926s Barometer, Standard, Fortin's principle, superior instrument, polished mahogany frame, tube, .5 in. bore, scale divided into ^ in. on one side and millimetres on the other, with double vernier, reading to .002 in. and .05 millimetre, and thermometer divided into deg. F. and deg. C. . . . . . . . . . . . . ..£850 1927s Barometer, Standard, as above, graduated in millimetres, only with vernier reading to .05 millimetre, and thermometer in deg. C. on polished mahogany board . . . . £7150 1928s Barometer, Standard, Fortin's principle, same as No. 1926, but with National Physical Laboratory Certificate . . . . . . . . . . . . £8 15 0 1929s Barometer, Standard, as No. 1926, in polished mahogany case with lock and key, as illustrated . . . . . . . . . . . . . . . . . . £10 0 0 1930s Barometer, Standard, as No. 1929, with National Physical Laboratory Certificate, in polished mahogany case as illustrated . . . . . . . . . . . . £10 10 0 See No. A 1931 for Special Export Barometer. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 387 2 C BAIRD &.TATLOCK (LONDON) LTD. Al931s Barometer, Standard, Fortin's principle, tube .3 in. bore, scale divided in & in. and millimetres, with double vernier, thermometer divided into C. and F. degrees, on oak board in glazed teak case, screwed together (as Figs. 1929-1930) Special pattern designed for Export. £8 5 1931 I 1932 1933 1931s Barometer, Mountain, Fortin's principle, with portable tripod stand and gimbals, tube T^j in. bore, scale graduated in inches and millimetres, with double vernier, in leather sling case .. .. .. .. .. .. .. .. .. £10 10 1932s Standard Barometer, improved by Professor Collie, with mechanical device for tem- perature corrections by Dr. Shields, on polished mahogany board, with mirror back on which scale is graduated in millimetres . . . . . . . . . . ..£44 (See Philosophical Magazine for May, 1896, pp. 406-413.) 1933s Student's Pattern Standard Barometer, Fortin's principle, bore of tube .25 in., with double scales divided into ^ inches and millimetres, on polished board, double vernier reading to .01 in. and .1 millimetre, and thermometer graduated in C. and F. degrees . . £312 Al933s Student's Pattern Barometer, as No. 1933, in polished mahogany case, with lock and key .. .. .. .. . . .. .. .. .. £4 17 -CROSS STREET • HATTCW GARDEN, E-C 388 BAIRD &TATLOCK (LONDON) LTD. 1934* 1935s 1934 1935 1937 Fortin's Barometer (Student's pattern), a copy of the Fortiri's Standard Barometer, No. 1926, but with tube .25 in., with double vernier and scale divided to read .01 of an inch , and .1 millimetre, on polished board, with thermometer divided into deg. C. and deg. F. £3 12 6 Barometer, new design, bronzed brass frame, iron cistern, compensated scale, direct reading (without cistern adjustment), bore of tube J in., range of scale 27^ to 33 in., on polished mahogany board, specially designed for use in Mines, with vernier reading to o.oi in. . . . . . . . . . . . . . . . . £3 18 0 1936s Barometer, as No. 1935, but with vernier reading to 0.002 in. . . . . ..£440 .\1936S Polished Mahogany Case, glazed, with lock and key, for Nos. 1935 or 1936 . . . . £150 Barometer, Marine, Board of Trade pattern, bore of tube .26 in. in bronzed brass frame with iron cistern. Bracket, arm, and gimbals complete, compensated scale graduated in inches, vernier to 0.002 in., and attached thermometer, in stained wood travelling case with lock . . . . . . . . . . . . . . . . £4 17 6 National Physical Laboratory Certificate for above . . . . . . . . extra £0 17 6 « 1937* 389 BAIRD &TATLOCK. (LONDON) LTD. B1937 B19378 Barograph or Self-Recording Barometer. This instrument will record the variations of the atmospheric pressure for seven days without attention, when it is necessary only to replace the paper chart. Fitted in polished mahogany case, with plate glass front, and a sufficient number of charts to last a year . . . . . . price complete £5 Charts either inches or millimetres. c!937s Barograph in all metal frame, iron base, hinged copper cover. Specially suitable for use in tropical climates. Size 10 x 5 X 7! in. Charts either inches or millimetres. £4 17 6 D 1937s Charts, millimetres or TV in. A. Ink .. B. Pens . per box of 52 weekly charts per bottle each £040 £009 £0 1 0 CROSS STREET • HATTOTsT GARDETST, E-C 390 BAIRD &TATLOCK (LONDON) LTD. Evaporating Basins. ROYAL BERLIN, GERMAN PORCELAIN, ETC. 1938 1939 1940-1941 1942 1938 Basins for evaporating, with spout, Finest Royal Berlin Porcelain, for analytical purposes, with royal mark, No. oo to No. 5, glazed inside and out ; No. 6 to 12, glazed inside and partially outside (with Government mark in blue, see illustration). No. oo o i 2 3 4 5 6 7 9 Diameter 2f 3^ 3§ 3i 4 4§ 4! sf .7^ 8J- io| Capacity 50 80 100 140 175 210 300 385 765 1285 2200 Price 6d. 7d. 9d. lid. 1/1 1/3 1/6 i/11 2/7 3/3 4/9 5/6 6/3 8/- 10/- 11/9 13/6 16/3 21/6 29/- 36/- 54/- 10 12 II 14 3250 5700 7/9 10/9 90/- 126/- 12 15! in. 10,000 C.C. 23/6 each. 270/- doz. 1939 Basins, Royal Berlin Porcelain, deep form, with spout (with Government mark in blue, see illustration). No. .... o i 2 3 4 5 6 Diameter Capacity Price . 4f 300 1/6 5* 500 2/3 64 800 2/9 7* 1160 3/6 71 1725 4/6 81 2325 log m. 3400 c.c. 9/- each. 1940 Basins, Royal Berlin Porcelain, flat form, with spout (with Government mark in blue, see illustration). No. Diameter Capacity Price . I 2f 45 7d. 6/3 2 s~i 60 9d. 3 3l 95 1/1 11/9 4 160 1/4 14/6 5 4i 200 1/8 18/- 54 35o 21/6 7 6| 550 2/6 271- 8J in. 1150 c.c. 3/3 each. 36,/- doz. 1941 Basins, flat, with spout, Royal Berlin Porcelain, wholly glazed, suitable for milk analysis, etc. (with Government mark in blue, see illustration). No. .. 12 Diameter Capacity Price . , 45 1/2 12/6 34 60 1/5 14/6 3f in. 95 c.c. 1/9 each. 18/- doz. 1942 Basins, Royal Berlin Porcelain, with handle and spout (with Government mark in blue). No. .. .. ..i 2 3 4 5 6 Diameter . . 2 2f 3| 4^ 5j 6J in. Capacity . . . . 30 75 150 375 750 1250 c.c. Price.. lid. 1/2 1/6 2/3 4/2 5/3 each. 1943 Basins, best German Porcelain, similar in shape and sizes to Royal Berlin make No. 1938, and very durable. No. oo to No. 5, glazed inside and outside ; No. 6 to No. 12, glazed inside and partially outside. No. 00 O I 2 3 4 5 6 7 8 9 10 ii 12 Diameter 2) 34 3l si 4 4l 4* 6 7i 8k 10 12 14 i5f »n. Price 3d. 4d. 4d. 5d. 6d. 7d. 9d. 1/2 1/6 2/2 3/2 V' 6/6 12/- each. .. 2/6 3/3 3/6 4/6 5/6 6/6 8/6 13/- I7f- 241- 36/- 57,'- 75/- 140/- doz. 1944 Basins, best German porcelain, glazed inside, unglazed outside. No. Diameter Capacity Price . I 2 3 4 5 6 7 2§ 2f 3f 3& 4l 5 54 30 40 80 120 170 200 300 3d. 3d. 4d. 4d. 5d. 6d. 8d. 2/9 2/9 3/6 3/9 4/6 5/6 7/6 420 lOd. 9 6| in. 525 c.c. lid. each. 10/6 doz. BAIRD &TATLOCK (LONDON) LTD. 1945 Basins, best German Porcelain, flat form, similar to Royal Berlin make (Fig. 1940). No. .... i 2 3 4 6 Diameter .. 2% 3^ 3| 4i 4t Si- Capacity . . 30 35 60 90 125 175 Price ... .. 3id. 5d. 7d. 7d. lOd. lid. 3"/3 4/6 6/3 6/6 8/6 9/6 7 6 1 in. 250 c.c. 1/1 each. 11 /- doz. 1946 1947 1949 1946 Basins, evaporating, Meissen (Dresden) Porcelain, shallow, thin, with spout. No. ooo oo 012 34567 9 10 ii Diameter 16 14^ 13! iif lof 95 8| 7^ 6i si 4! 4J 3i 2-i- in. Capacity 8700 6200 4750 3750 2250 1700 iioo 870 525 280 190 120 50 20 c.c. Price 16/6 151- 10/- 7/6 5/3 4/9 3/10 3/- 2/4 1/6 1/2 lid. 5d. 5d. each. 118/- 88/- 61/- 56/- 45/- 35/- 27/- 17/- 13/6 10/6 4/9 4/9 doz. 1947 Basins, German porcelain, with lid and wooden handle. No. . . . . . . oo i 3 4 Capacity • • • • 125 275 750 c.c. i Diameter . . . . 8.5 n 14 16 Price .. .. .. I/- 1/6 2/9 3/3 1948 Basins, German Porcelain, with porcelain handle and spout, as Fig. 1942 No. . . . . . . oo o i 2 Diameter . . . . 85 95 105 115 Capacity, about . . . . 125 200 275 400 Price ". . .. .. 7d. 8d. 9d. 1/2 6/6 7/6 8/6 13/6 1949 Basins, evaporating, enamelled cast iron, with lip and wire handles. Diameter . . 6 8 10 12 14 Price .. .. 1/4 1/9 2/6 3/6 6/- 5 1.5 litre. 18 centimetres. 4/6 each. 3 135 700 1/7 18/6 16 7/6 160 mm. 1200 c.c. 2/3 each. 26/- doz. 18 in. 10/6 each. 1950 1951 1952 1950 Basins, evaporating, light enamelled steel, with rounded bottom and handles. Diameter .. .. 3$ 4^ 5* 7* gj Price .. .. .. 8d. lOd. 1/2 1/9 2/8 „ .. .. 7/6 9/6 13/- 201- 30/- n| m. 3/10 each. 44/- doz. 1951 Basins, pure nickel, Scheibler's, with brass counterpoise, as used in sugar analysis . . each £050 1952 Basins, glass, deep form, with spout, round bottoms, of light Bohemian glass. Diameter . . ij 2j 2| 3^ 4 4! 5 Capacity .. i 2 3 5 8 11 16 Price .. .. 2d. 3d. 4d. 5d. 6d. 7d. 8d. 1/9 2/9 3/6 4/6 5/6 6/6 7/6 5i 18 lOd. 6J in. 25 oz. lid. each. 10!- doz. CROSS STREET • HATTCTN GARDEN, E'C BAIRD &. TXTLOCK (LONDON) LTD. 1953 1954 1955 053 Basins, thin glass, finest Bohemian, flat bottom, without spout. Diameter . . i\ 2f 3& 3& 4 Price .. .. 3d. 3d. 4d. 5d. < 2/6 2/9 3/6 4/6 i '»54 Basins, thin Bohemian glass, flat form, with spout. i 2 34567 Piumeter i ij i| 2j af at • z\ Capacity 2 drm. 3 drm. i a 2j 3$ 4^ Price 2d. 2d. 2d. 3d. 4d. 4d. 4d. 1/9 1/9 1/9 2/9 3/6 3/9 3/9 4/6 5/6 5/9 6/6 7/6 9/6 doz. 1055 Basins, Resistance glass, specially suitable for water analysis, without spout. Diameter . . . . . . . • . . 80 100 ia5 millimetres. Price .. .. .. .. .. .. 8/- 10/6 15/- per doz. 41 5t 5t 61 in. 1. 6d. 7d. s.l. lOd. each. 6 5/9 6/6 7/6 9/6 doz. 8 9 10 ii la 13 31 31 • 3l 4f 5i 51 in. 6 7 9 14 24 30 oz. 5d. 6d. <>.!. 7d. 8d. lOd . each 1056 Basins, Bohemian glass, round bottoms, without spout, for water analysis. Diameter, n centimetres . . . . . . . . . . each, 8d. ; per doz. £076 1957 1958 1959 1 Basins, clear glass, for pneumatic troughs or specimens, extra strong. . . 6 by 4 8 by 4 10 by 5 12 by 5 P"ce .. ..II- 1/3 2/6 3/6 1958 Basins, pure nickel, round bottom, with spout. Diameter . . 1 1 I s 2 Price .. .. 1/3 1/4 1/7 21 1/10 3* 4 3/10 1959 Basins, with spouf aluminium. Diameter Each .. .. .. Per dozen 2 lOd. 9/6 21 lid. 10/6 3 i/- 11/6 31 1/3 14/- 14 by 6 in. 5/- each. 6 in. 6/9 each. 4 in. 1/4 15/- )i)CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 393 BAIRD &TATLOCK (LOM)ON) LTD. V>£ y £*»& X y I960 1961 1960 Evaporating Basins, new Jena Glass, with flat bottom (thick walled, as a substitute for porcelain). in). External diam. across rim Price 40 4d. 3/9 50 5d. 60 5d. 4/3 70 6d. 4/10 80 7d. 90 8d. 1961 Basins, copper, round bottom, spun in one piece, edges wired. Diameter Price 1962 Basins, tinned, suitable for sand baths, etc. Diameter 6 in. 1963 Basins, platinum (see No. 2348). 1964 Basins, silver, to order 1965 Basins, lead, for fluoric acid, 2\ in. diameter 4 1/2 6 2/- 100 9d. 8/3 8 3/- 125 1/1 13/3 9 4/- 150 millimetres. 1/6 each. 17/6 doz. 10 in. 51- each. each, 4d. ; per doz. £0 per oz. troy about £0 each, 6d. ; per doz. £0 3 9 9 0 5 0 1966 1967 1968 1969 1966 Lead Apparatus for decomposing minerals in hydrofluoric acid, outer basin 14 centimetres wide by 7 centimetres deep, with lid, inner basin, and tripod 1967 Lead Apparatus for hydrofluoric acid, about 250 c.c., with cover and tripod 1968s Dyers' Pans, salt glazed. 12345 Price .. .. 2/- 4/- 5/6 7/6 9/6 1969s Mixing Pans, salt glazed, with or without tubulure at bottom. 2468 6 gallons. ll/- each. 10 gallons. Diameter inside . . 8f "J 13 14 15 in. Depth inside ii nj 14 isi i/J in. Price 4/6 ?/• 13/- 17/6 22/~- each. 1970 Beads, clear glass. Small. Medium. Large. 1/9 1/6 1/4 per Ib. 394 BAIRD &TXTLOCK (LONDON) LTD. WARRANTED QUALITIES OF "RESISTANCE" GLASS. " Resistance " Glass, lately again improved, is not surpassed by any other glass on the market in resisting sudden changes of temperature, and the action of hot water as well as of corrosive chemicals. No solution of in be detected, and beakers or flasks maybe used with naked flame of a Bunsen Burner without risk of Breakage. The articles made of this glass are well finished, and will prove to be considerably larger than stated, the capacity indicated tilling the vessels only up to 3 — J of the height and not up to rim as frequently in practice. All vessels bear the registered trade mark R in circle and the capacity in ccm. stamped on; tubing shows blue stripes. Interior imitations being sold, precaution is necessary in purchase. In glass of ordinary quality it is found that nearly always about 200 — 400 thousandths of a mg. of constituent matter are dissolved out of a surface of 100 cm. square. The insolubility of our " Resistance " glass has reduced this to 2 thousandths of a mg. in cold water and Tj^mg. in hot water. (See Certificate of Reich' s-Anstalt, Charlotlinberg), 1971 Beakers of Resistance 1971 1972 Glass, squat form with spout. (Each beaker hears our brand No. Height Diam. at centre of body outside Total capacity Price . . In Sets. No. Price 1972 Beakers of Genuine Bohemian No. Height Diam. at centre of body outside Total capacity Price No! !! !.' Height Diam. at centre of body outside Total capacity Price .. In Sets. No. Price if 65 3d. 2/9 Glass, i 65 3d. 2/3 1800 l/- ll/- lOd. 8/9 2| 2 125 4d. 3/3 and capacity.} 5 4l 3i 540 7d. 6/6 6 4i 3£ 750 8d. 7/3 7 5* 34 1000 9d. 8/6 8 6 in. 4i in- 1390 c.c. lid. each. 10/3 doz. 1-3 1-5 1-8 lid. 2/- 4/4 per set. 9/9 21/6 47/6 per doz. sets, well annealed, squat form, with spout 2 2§ 2 125 3d. 2/6 10 5 2.350 1/2 3 3* 2| 22O 5d. ii 84 51 3000 1/6 1/10 19/3 4 5 6 7 8 3l 41 4l 6 in. 2| 3l 4i in. 350 540 750 1000 1390 c.c. 5d. 7d. 8d. 9d. lOd. each. 4/6 6/- 7/- 8/6 9/- doz. 12 13 14 15 16 9 9* I0i ii 12 in. si 6J 6J 7 1\ in- 3850 4800 5500 6750 8350 c.c. a/- 2/6 3/6 41- 4/6 each. 22/- 28/- 40/- 46/- 52/- doz. 1-8 I-I2 1-16 41- 9/6 24/- per set. 43/6 !=«)£& 106/- — per doz. sets. (G%^ 395 BAIRD &. TATLOCK (LONDON) LTD. 1973 1974 1975 1973s Beakers, low form with spout, new Jena Glass. Capacity Height Diameter Price 1974 Beakers of Genuine Bohemian Glass, well annealed, medium form, without spout. 50 100 150 250 400 600 800 IOOO 1300 c.c. 55 60 75 85 IOO "5 135 145 160 45 5« 55 65 75 85 95 105 no mm. 3d. 4d. 4d. 5d. 6d. 8d. 9d. lOd. I/- eacl1 3/- 3/3 3/6 4/4 5/9 71- 8/3 9/6 11/3 doz No. Height Diam. at Capacity Price No. Height Diam. at Capacity Price In Sets. No. Price 1975 Beakers of Resistance No. Height Diam. at Capacity Price In Sets. No. Price I 2 3 4 5 6 .. 2i 2f 3i 3f 41 4s ly outside i-J- If It 2i 25 2 1 . . 70 loo 150 220 310 470 .. 2d. 3d. 4d. 4d. 5d. 6d. .. 1/9 2/9 3/3 3/9 4/3 5/6 9 IO II 12 13 14 7f Si 9* 10^ Hi dy outside 3f 4i 4s 5 51 5l" - • 1340 1700 2250 3000 4000 5200 . . 9d. lid. l/- 1/3 1/8 2/6 . . 8/6 10/- ll/- 14,.'- 18/- 28/- i-3 i-5 1-8 I-I2 . '. 8d. 1/5 3/- 6/6 .. 7/9 15/3 34/9 78/3 {p\J Glass, medium form without spout. IB T 1 (Each beakei' bears our brand k L > 1 and capacity.} I 2 3 4 5 6 2 1 2f 31 3f 4| 4l ly outside i| If I| .. 70 ioo 150 220 310 470 .. 3d. 3d. 4d. 5d. 6d. 7d. . . 2/6 2/9 3/3 3/9 4/9 6/- 34 670 7d. 6/6 6J 6500 3/6 40/- 6^ in. 3A in. 900 c.c. 8d. eacl 7/6 do: 16 I3i in. 6| in. 8000 c.c 4/- eac 46/- doz 1-16 17/6 per set. — doz. set 7 5i 670 8d. 8 6j qoo c.c 9d. eac 8/- doz 1-3 1-5 1-8 lOd. 1/6 3/6 per set. 8/6 17/- 38/- per doz. sets. CROSS STREET • HATTO1ST GARDE1ST, E-C- BAIRD &.TATLOCK (LONDON) LTD. '77s Beakers, New Jena glass, tall form, with spout (measurements as No. 1976). Capacity 50 100 150 200 300 400 500 600 800 1000 1300 1500 c.c. Price 3d. 4d. 4d. 5d. 6d. 6d. 7d. 8d. 8d. lOd. lid. I/- each. 2/9 3/3 3/6 4/- 5/3 5/8 6/3 7/- 7/6 9/- 10/3 10/10 do/. 1976 1977 1978 76s Beakers, New Jena Glass, tall form, without spout. Capacity . . . . . . 50 100 150 Height . . . . 67 80 90 Diameter . . . . . . 40 47 50 Price .. .. ..3d. 4d. 4d. ..2/9 3/3 3/6 200 300 400 500 600 c.c. IOO 1 20 130 140 150 mm. 55 63 70 75 80 mm. 5d. 6d. 6d. 7d. 8d. each 4/- 5/3 5/8 6/3 7/- do/.. Capacity Height Diameter Price 800 165 85 8d. 7/6 IOOO 185 90 lOd. 1300 1500 205 2IO 95 ioo lid. II- 2000 2500 235 250 no 120 1/3 1/6 3000 280 130 1/9 4000 c.c. 290 mm. 140 mm. 2/- each. 10/3 10/10 12/9 15/- 17/6 20/6 doz. )78 Beakers of Genuine Bohemian Glass, well annealed, tall form, without spout. No. . . . . . . ooo oo o i 23 Height .. .-if 2 2| 34 4 4 Diam. at centre of body outside i ij if li if 2 Capacity . . . . 20 30 45 90 150 230 Price .. .. .. 2d. 2d. 2d. 3d. 4d. 5d. ..1/6 1/8 1/10 2/9 3/6 4/6 4 5 340 6(1. 5/6 5 51 in. 2§ in. 470 c.c. 7d. each. 6/6 doz. No. Height Diam. at centre of body outside Capacity Price In Sets. Nos. Price 6 6 2 1 62O 8d. 7/6 3i 890 9d. 8/6 000-2 I/- 11/3 3i 1150 lOd. 9/6 r-5 21- 22/- 9 8 31 1460 I/- 11/6 10 9 4* 1850 1/3 I4/- ii 9t 4i 2400 1/4 15/- 12 9J in. 4i in- 2900 c.c. 1/8 each 18/- doz. 1-8 I-I2 4/4 9/- per set. 48/- 96/- per doz. sets. 397 BAIRD &TXTLOCKL (LONDON) LTD. 1979 1980 1981 1979 Beakers, Bohemian Glass, extra wide, 4! by 4! in. 1980 Beakers, Porcelain, Royal Berlin make, without spout. No. . . . . i 2 Height 3 1 4! Diameter . . . . 2| 2J Capacity . . . . 5t ni Price .. .. 1/6 2/3 1981 Beaker Flasks, Best Bohemian Glass. Capacity . . . . 100 150 Price . . . . 3/- 4/- 1982 Beakers (conical), Phillips, Best Bohemian Glass. Capacity 2 4 6 8 10 Price 3d. 4d. 4d. 4d. 6d. 2/9 3/- 3/3 3/9 5/- 1982 each, lOd. ; per doz. £0 9 C 2a 3 4 5 6 7 8 5i 5 a 7i 8J 9i "I in. 2I 3 31 4i 41 4! 7J in. 14 20 33 51 60 72 170 oz. 2/5 2/9 3/9 5/3 6/6 18/9 each. 200 300 400 500 600 800 1000 c.c. 4/6 4/9 5/- 6/6 77- 8/- 9/6 per doz. Glass, 12 16 20 30 40 50 60 80 oz. 6d. 7d. 8d. 9d. 11- 1/2 1/5 1/9 each. 5/6 6/- 7/- 8/6 10/6 12/6 15/- 19/: doz. 1983 1983 Beakers, enamelled steel, without spout. Diameter Height Each Per dozen 1984 1985-1990 2j 2| in. • • 3 3f in. .. 6d. 7d. .. 5/6 6/6 1984s Copper Beakers, spun in one piece without seam, with spout 5^ in. high by 3! in. diameter at centre, tinned inside . . . . , . . . . . . each 1985s Copper Beakers, spun in one piece, with cover, without spout, 5 in. high by 3^ in. diameter . . . . . . . . . . . . . . . . each 1986s Copper Beakers, spun in one piece, with cover, without spout, 5 in. high by 3 in. diameter . . . . . . . . . . . . . . . . each 1987s Copper Beakers, spun in one piece, with cover, without spout, 4 in. high by 2f in. diameter . . . . . . . . . . . . . . . . ' each 1988s Copper Beakers, spun in one piece, with cover, without spout, 3! in. high by 2j in. diameter . . . . . . . . . . . . . . . . each 1989s Copper Beakers, spun in one piece, with cover, without spout, 3 in. high by 2 in. diameter . . . . . . . . . . . . . . . . each 1990s Copper Beakers, spun in one piece, with cover, without spout, 2f in. high by if in. diameter . . . . ..... . . . . . . . . each Nos. 1985 to 1989, without cover, 9d. each less; No. 1990, without cover, 6d. each less. £0 £0 £0 £0 £0 £0 3 3 3 2 2 2 £0 1 CROSS STREET • HATTCHST GARDEN, E-C toe BAIRD &TATLOCK (LONDON) LTD. 1991 1992 1993 1994 1991 Bell Jar, ground rim, with glass stopcock at top ground to fit, 10 by 6 in. 1992 Bell Jars, stoppered, with ground rim, of clear glass. Height to shoulder . . 6 6 8 8 Diameter . . . . 3 4 4 6 Price .. .. 1/6 21- 2/6 3/- 1993 Bell Jars, knob and ground rim, for air pumps, etc. Height to shoulder 334567 Diameter . . 465567 Price .. 1/4 2/- 2/- 2/3 2/6 3/6 1994 Bell Jars, open at top, and with ground rim. 7 by 5 8 by 4 £076 9 10 10 10 12 12 in. 6 5 7 8 6 Sin. 3/6 3/3 4/6 5/- 4/6 5/6 each 8 8 3/9 9 10 !/"- 4/6 8 by 5 in. 2/3 each. 12 6 12 in. 8 in. 5/- each. 1995 1996 1997 1995 Gas Bags of Goldbeaters' skin, with brass stopcock . . . . . . . . each £030 1996 Bell Jars, green glass, with knob, and without flange, low form, for covering specimens, etc. Height . . . . . . . . 4 5 6 in. Diameter . . . . . . . . . . 8 10 12 in. Price . . . . . . . . 21- 2/9 3/6 each. 1997 Bell Jars, green glass, with knob, and without flange, tall form, for covering microscopes, etc. Height 3 4 5 6 7 8 9 12 15 18 in. Diameter -.3 3 4 4 3 4 5 6 7 8 in. Price .. 9d. lid. I/- I/- I/- 1/3 1/9 2/6 3/6 4/6 each. (CHEMICAL AND SCIENTIFIC APPARATUS AlsID PURE CHEMICALS- 399 BAIRD &TATLOCK (LONDON) LTD. 1998 1999 1998 Gas Jars, with brass cap and stopcock. Size . . . . 8 by 5 9 by 6 Price .. .. 6/6 7/- 2000 10 by 7 7/6 12 by 8 in. 9/- each. 1999 Sach's Double Bell Jars, for holding various coloured liquids used in botanical research. Internal height Internal diameter Price 4f 15 51 20,'- 9i 7 201- 15 in. 7 in. 23/- each. 2000 Bell Jars, with tubulurc at bottom, and ground flange. Open at top. 12 by 6i 7 by 5 in. 6/- 4/6 each. 2001 2001 Blowpipe, mouth, Black's, japanned tin with nozzles screwed on 2002 Blowpipe, improved, brass, with vulcanite mouthpiece 2003 2004 2003 Blowpipe, mouth, best nickel-plated, ivory mouthpiece 2004 Blowpipe, with platinum nozzle screwed to fit 2005 Blowpipe, mouth, brass, with bone mouthpiece 2002 each, 5d. ; per doz. 1/3; £0 4 £0 14 2005 each, 1/6; per doz. £0 17 each £0 9 each, 1/4; per doz. £0 15 2006-2007 2006 Blowpipe, nickelled brass, 6J in. . . 2007 Blowpipe, nickelled brass, 8| in. . . each 5d.; per doz. £0 4 6d. ; £0 5 CROSS STREET • HATTCrtST GARDETST. E- C-* u 400 ,- - BAIRD &TATLOCK (LONDON) LTD. 2008 2009 2010 2008 Blowpipe, mouth, with regulating stopcock for connecting direct to gas supply . . each £0 5 6 2009 Blowpipe, Herapath's, with indiarubber tube and mouthpiece, to fit on to b'unsen burner. Price without burner . . . . . . . . . . . . . . ..£030 2010 Blowpipe, brass, on universal joint, adjustable to any position, two stopcocks, and with two extra jets screwed on to sole . . . . . . . . ..£0126 j 2011 2012 2013 2014 2011 Blowpipe, for gas and air, two stopcocks, for general work .. .. £0 10 0 2012 Blowpipe, for crucible work, with one stopcock for air . . ..£076 2013 Blowpipe, for use with acetylene gas .. .. .. .. .. £0 12 6 2014 Blowpipe, glassblowers' pattern, for use with glass jets of various sizes, which can be changed without putting out gas flame .. .. .• . . £0 12 6 BAIRD & TATLOCK (LONDON) LTD. 2015 2015 Blowpipe, as No. 2014, on brass pillar, height 4 in. . . 2016s Blowpipe for working with Methylated Spirit (Regd. No. 528481), as made to Col. Aldridge's specification, with copper reservoir on wood base and sliding blowpipe jet for use with blower, No. 2025 2017 2018 2017 Fletcher's Compound Blowpipe, improved pattern For glassworkers and experimental laboratories (see Shenstone's " Method of Glass Blowing," Rivington's). A double concentric blowpipe, the gas and air changing automatically from the larger to the smaller blowpipe by the slight movement of the lever at the back, the same movemefit also adjusting both gas and air to each other for each blowpipe, giving the fullest and most instantaneous control over the character and size of the flame, without necessitating the use of the hand, the two blowpipes being perfectly concentric. 2018 Fletcher's Oxygen Blowpipe, for use with compressed oxygen. No. . . . . . . . . 7 20 40 Oxygen, per hour . . 7 20 40 cubic ft. Gas supply , . £ I m- Size . . . . . . . . 9! 12 14^ in. Price . . . . . . . . 8/6 10/- 12/"- Price, with stopcock . . 13/- 16/- 18/- N.B. — The blowpipes are totally useless for coal gas and air ; they are specially designed for use with compressed oxygen only, 14 CROSS STREET • HATTOTST GARDEN, EC BAIR-D &TATLOCK (LONDON) LTD. 2019 2019 Fletcher's Automatic Blowpipe, pattern C. Both gas and air are controlled simultaneously No. . . . . . C 10 C 40 C 80 Size . . . . . . • 8£ I2j i6£ in. Gas supply .... i i in. Foot blowers, size required 355 Price .. .. 9/- 11/6 18/- Price on stand . . . . . . 12/6 17/6 — 2020 2020 Fletcher's Pattern 8C Blowpipe. No. Size Gas supply Price without taps Price with taps . . 4/3 2 Mi i 77- 15/- 271- 4 24 1 in. i in. 351- 53/- 2021 2022 2021 Blowpipes, light and handy, suitable for general laboratory work, soldering, and very light brazing. Overall length . . . . . . 7^-in. Outside size of air tube . . . . £-in. Outside size of gas tube . . . . £-in. Price . . . . . . . . 5/- A No. 3 Foot Blower is required to work above blowpipe. (See No. 2023.) 2022 Blowpipe, small pattern, for use with gas made from Gasolene. Overall length Price loi-in. ioy- 403 BAIRD &TXTLOCK. (LONDON) LTD. 2023-2024 2025 2023 Foot Blower 2024 Foot Blower Reservoir. 8 in. Ounces. 20 oz. sq. in. 20 , Foot Blowers. These foot blowers are fitted with two indiarubber discs to form an air reservoir, which gives an almost steady air pressure. Size over all, including Diameter of Air Pressure in Step and Air Pipe 14 by io£ by 7 in. I5i by ii by 7f in. 10 „ No. 3. 2025 Foot Blowers, sizes as Nos. 2023-2024, but with tripod . . 29/- 2026s Rubber Discs, for Nos. 2023-2025 .. .. each 2/4 2027 Nets ., „ .. .. .. I/- (Two rubber discs on each blower.) Size. No. 3. No. 5. Size of Air Pipe. T7*in. tV in- No. 5. 33/6 1/4 2028 2028 Foot Blower, with spring reservoir in place of indiarubber discs. Fitted for the roughest general use, but not giving so steady pressures as above. Sizes same as No. 2023-2024. Price — No. 3, 35/- ; No. 5, 40/- CROSS STREET • HATTON GARDEN, E-C- BAIR-D &.TATLOCK (LONDON) LTD. 2029 20291 Belt-Driven Blowers. 2030 We supply, where our clients prefer to drive by belt from their own shafting, a series of blowers fitted with fast and loose pulleys and belt-shifting gear, of the same capacity as electric blowers, No. 2030. Size . . . . . • • • • • i 2 Cubic ft. per min. capacity . . . . . . 5 15 Speed, revolutions per minute . . . . 800 700 Price .. .. £4 0 0 £5 0 3 25 600 £7 0 0 4 40 500 £10 0 2030T Electric Blowers for gas forges, oil furnaces, laundry burners, heating and drying stoves, smiths' fires, brazing, grain cleaning, circulating gases and vapours, glass blowing, enamelling, brass and iron melting, gas exhausting, mixing and blowing air into fluids, dust blowing, dust separators. The following table gives details of each stock size of Blower at its normal working speed. Every Blower is capable of giving a pressure of 7 Ibs. per square inch, and of working continuously without undue friction, heating, noise, excessive lubrication, or waste of power. They are positive in action, and will run steadily for years without repair. They are extensively used wherever a continuous steady air blast is required, and are immensely superior to any other Blower. They may be constructed of any size or material for any purpose. Size .. .. .. .. o i 2 3 4 Cubic ft. per min. capacity .... 2 5 15 25 40 Power of Motor Price J H.P. £6 10 0 J H.P. £9 10 0 i H.P. £14 0 0 | H.P. £16 10 i H.P. £20 0 0 When ordering, please state voltage, and if alternating or continuous current. Henrici Hot Air Motor fitted with blower. (For illustration, see page 406.) This favourite rotary blower has the advantages over a piston-pump in that it gives a permanent and energetic current of air, has no oscillating or knocking parts. These apparatus are recommended especially for air-gas plants, chemical laboratories and wherever a continuous current of air is wanted. Bore of engine H.P. of motor . . . . Revolution of blower per minute Approx. output of the blower in cubic metres of air per hour against a resistance of 2 in. W.G. 2031T Price complete with blower with gas burner 20321 Price complete with blower with spirit burner For hot air engines only see Nos. 911-913. 40 450 54 A 450 65 400 80 mm, 450 4-5 9-3 13-5 30.0 £9 12 6 £11 2 6 £13 5 0 £18 15 0 £9 12 6 £11 17 6 £14 7 6 £19 17 6 BAIRD &TATLOCK (LONDON) LTD. 2033 For prices see page No. 405. 2031-2032 2038 2033T " Roots " Power Blower. These give a pressure of about i Ib. per sq. in., but the pressure is not guaranteed by the makers. Size of blower Maximum number of revolutions per 'minute Air delivered per minute Number of fires it will blow at this delivery Diameter of outlet . . . . inches Price . . 2034T Extra for escape valve 2036T Extra for fast and loose pulleys 2037T Extra for hand driving gear 2038T Blowpipe Table, with double-action bellows, hardwood top, size 36 by 30 in., and two drawers for tools, suitable for glass-blowing or other blowpipe work, with heavy iron weight for air pressure . . . . . . . . . . . . . . ..£4101 For blowpipes for use with above table see Nos. 2014 and 2015. 05 06 07 08 09 300 180 300 90 300 64 300 35 300 20 cub. ft 2 i — — — 3 330/- 2* 245,'- 2 198/- if 154/- I* 110/- 20/- 10/- 10/- 10/- 10/- 20/- 15/- 15/- 12/6 12/6 90/- 45/- 45/-' 40/- 40/- CROSS STREET • HATTOTST GARDETST, E-C 406 RAIRD &TATLOCK (LOM)ON) LTD. 2039 2040 2039s Blowing Balls, of red indiarubber, about ico c.c. capacity, with valve. each, 2/- ; per doz. 2040s Blowing Balls, best quality indiarubber, with net covered reservoir. Diameter of reservoir when inflated . . . . about 2\ 3$ in. Kueh . . . . . . . . . . . . 2/6 31- Per dozen .. .. .. .. .. 29/- 35/- 2041 Blowpipe Charcoals, compressed, 2f by ij by i J in. .. ... .. per doz. 2042 Blowpipe Charcoals, compressed, 6 by i by i in. . . 2043 Blowpipe Charcoals, natural, about 4 in. long and I in. thick . . ,, £120 £0 £0 £0 2 6 5 0 2 6 2045 2044 2047 2049 2050 2044 Charcoal Pastilles, for use with the blowpipe 2045 Supports, Porcelain, for Charcoal Pastilles 2046 Charcoal Pencil 2047 Charcoal Saw 2048 Cedarwood Spills (130 spills in each bundle) . . per bundle, 6d. 2049 Charcoal Borers, large, with handle 2050 Charcoal Borers, small, with handle 2051 Charcoal Borer, steel, small, with spatula end 2052 Clay Troughs, rectangular, i by f in., for blowpipe work 2051 2052 per doz., 6d. ; per gross £0 each, 5d. ; per doz. £0 each £0 per doz. bundles each . . per doz. 5 4 0 £0 0 £0 5 £0 1 £0 0 10 £009 £0 1 6 2053 2053 Platinum Wire Holder .... .... each £0 1 0 (For other apparatus used in Blowpipe Analysis see Assay Section at end of Catalogue.) ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 407 BAIRD &_ TATLOCK (LONDON) LTD. 2054 2055 2056 2054 Bottles, finest English flint glass, hand-made, and accurately stoppered. 2055 Capacity J Price, N.M. 4/9 Price, W.M. 5/3 5/6 5/6 4 6/6 7/- 6 71- 8 8/3 10 9/3 8/9 9/9 12 9/9 111- 16 10/6 2056 Bottles, clear glass, moulded, English make, stoppered. Capacity Price, N.M. . . 2057 20 40 oz. 17/6 per doz. 11/6 12/- 18/6 2057 Price, W.M. J i 2 4 6 8 10 oz. 2/3 2/3 2/9 3/3 3/9 4/6 «/• per doz. 26/- 26/- 32/- 38/- 43/- 52/- 58/- per grosi 2/6 2/6 31- 3/9 4/3 5/- 5/6 per doz. 28/- 30/- 34/- 43/- 49/- 58/- 64/- per gros; 2058 2059 2058 Bottles, English moulded, extra wide mouth, upright stoppered, for pickling specimens, etc. Capacity . . . . . . . • . .' i 2 4 6 8 oz. Height to top of neck . . 2.\ 2f 3 4 4! in. Diameter of neck inside . . . . if i£ if if 2 in. Price . . . . . . . . . . 3/6 4/- 4/6 5/- 5/6 per doz. . . 40/- 46/- 50/- 58/- 63/- per gross. 2059 Bottles, best clear glass, with extra wide mouth, flat stoppered, for pickling specimens, etc. Capacity Height without stopper Diameter of mouth inside Price »» • * ^rtS&\ .. 60 '.'. I* .. 4/3 .. 48/- 125 3| if 56/- •v^^— ;-. 175 2 6/6 74/- SSsr-»=£3 250 3i 4 7/6 84/- 3=p» 500 5 2| 9/6 108/- 1,000 4" 16/6 192/- 2,000 71 4i 25/- 288/- c.c. in. in. per doz. per gross. —riL?^^ ffj 14 • CROSS STREET • HATTO:H GARDEN, E-c-^jni 408 BAIRD &TATLOCK (LONDON) LTD. 2060 2061 2062 2060 Bottles, English, light green glass, well stoppered, narrow mouth, moulded " Winchester Series." Capacity 4 8 12 16 20 24 32 40 48 60 90 oz. Price 3/- 3/6 4/- 5/- 5/6 6/- 6/6 7/- 7/- 7/6 8/6perdoz. 34/. 4Q/- 46/- 58/- 64/- 70/- 76/- 82/- 82/- 88/- 96/- per gross. 2061 Bottles, best quality clear glass, narrow mouth, flat stoppered, for reagents, etc., hard glass, free from lead, bottles and stoppers numbered. Capacity Price »» Capacity Price 250 300 c.c. 5/- 6/- per doz. 58/- TO/- per gross. ii 2 litres. 15/- 17/- per doz. 176 1- 200 /- per gross. 2062 Bottles, best quality clear glass, wide mouth, flat stoppered, for dry chemicals, etc., hard glass, free from lead, bottles and stoppers numbered. 15 2/6 28/- 350 6/3 721- 30 3/- 34/- 500 7/4 86/- 60 3/6 40/- 625 8/- 94/- 125 4/- 46/- 750 c.c. 8/6 100/- 175 4/6 52/- i 10/ 115/- Capacity Price i» Capacity Price 15 34/1 350 821- 30 3/6 40/- 500 94/- 60 */: 46/- 625 106/- 125 4/6 521- 750 c.c. 9/6 1121- 175 5/6 641- 13/- 154/- 250 */- 701- li 16/- 190/- 300 c.c. 6/6 per doz. 76 /- per gross. 2 litres. 21 /- per doz. 248/- per gross. 2063 2064 2063 Bottles, clear glass, second quality, narrow mouth, flat stoppered, for reagents, etc. fin 125 175 250 300 350 500 C.C. 2/9 3/3 3/9 4/- 4/6 5/- per doz. 31/- 37/- 43/- 46/- 52/- 58/- per gross. Capacity Price 60 2/6 28/ 2064 Bottles, clear glass, second quality, wide mouth, flat stoppered, for dry chemicals, etc I Q T^Qr-ltx? AJ-V ff*r* -r r~~ n r* n '^f\f\ 1^/"\ tf f~\f\ f* Capacity Price 2/9 31/- 125 3/3 38/- 175 3/6 40/- 250 47- 46/- 300 4/6 52/- 350 51- 581- 500 c.c. 5/6 per doz. 64/- per gross. 409 _ _ BAIRD &TATLOCK (LONDON) LTD. 2065 2066 2068 2069 2071-2073 2065 2066 2067 2068 2067 Bottles, clear glass, narrow mouth, flat stoppered, for storing stock solutions, etc. Capacity . . . . . . 3 5 10 15 litres. Price .. .. 1/6 2/6 5/- 6/6 each. 17/- 29/- 58/- 74/-perdoz. Enamelled Labelled Bottles. White letters can be affixed to any flat stoppered bottles, Nos. 2061-2064, to order. Prices for labelling only (white letters with white border) — 2 to 10 12 tO 2O 24 tO 40 OZ. 7 /- 10/- 13/- perdoz. Enamelled Labelled Bottles as 2066 white letters only. Prices for labelling only — 2 to 10 12 to 20 24 tO 40 OZ. 6/- 9/- 12/- per doz. Bottles, clear glass, narrow mouth, flat stoppered, with best quality enamel labels, black : on white ground, bottles and stoppers numbered. Bottles labelled for Hydrochloric Acid, Nitric Acid, Sulphuric Acid, Ammonia, Potass Hydrate, and Sodium Hydrate kept in stock ; all other label: supplied to order. Special quotations given for quantities of any one label. Capacity . . . . 125 175 250 350 500 750 c.c. Price .. .. 1/4 1/6 1/7 2/- 2/3 2/6 15/- 17 /- 18j- 22/- 251- 28,1- See also Nos. 2074-2077, suitable for storing i litre. 2/9 each. 30/- perd 2069s Bottles, N.M., flat stoppered, new Jena glass. arsenic free acids, etc. Capacity . . . . . . 250 500 1000 2000 c.c. Price .. .. .. I/- 1/6 2/- 2/9 each. Ill- 111- 23/- 31/6 perdoz. , rtiuii r labels °\ 2070 2071 2072 Bottles, Resistance glass, narrow mouth, for storing standard solutions, etc., with flat stoppers well ground in (as Fig. 2069). Capacity Price Bottles, clear glass, narrow mouth, Labels. Capacity Price l/- 111- t 1/3 14J- i 1/6 17/- flat stoppered. First quality 2 litres. 2/3 each. 26 / - per doz. No. 2061, with Sand Blaste 125 175 8/6 250 9/6 350 10/3 500 c.c. 11/4 per doz. Bottles, clear glass, narrow mouth, flat stoppered. Second quality, No. 2063, with Sand Blaste Labels. Capacity . . . . . . 125 175 250 350 500 c.c. Price :. .. .. 6/9 7/3 7/9 8/6 9/- perdoz. BAIRD &TATLOCK (LONDON) LTD, 73 Bottles, amber glass, narrow mouth, flat stoppered, for silver nitrate solutions, etc. Uniform in shape with No. 2061, bottles and stoppers numbered. Capacity . . 15 30 60 125 175 250 350 500 c.c. Price 2/6 3/- 3/6 4/- 4/6 5/3 6/- 7/6 perdoz. -M Silvnir llAcfi eH IMI r-ffi nil fin i in i ii ~i n ~n i «i ST. 2106 2107 2108 2106 Bottle, Drop, devised by Mr. F. R. Chopping, with I.R. teat each, 7d. ; per doz. This bottle has been designed to hold staining reagents, etc. It is a modification of Schuster's Alkalimeter. The glass stopper has been replaced by a rubber teat ; manipulation of this produces anything from a fine steady stream for washing over slides, to a single drop for staining purposes. The bottle has been made of squat form with a wide base, giving it stability, which experience has shown to be very desirable. A special advantage is that it can be used with equal facility with either hand. 2107 Schuster's Alkalimeter s, stoppered, capacity 50 cubic centimetres each, 6d. ; per doz. 2108 Schuster's Alkalimeters, unstoppered, capacity 50 cubic centimetres each, 5d. ; per doz. 2109 2110 2111 2109 Bottles, best clear glass, stoppered, with ground glass cap, for ether, etc. Capacity J ' • I 2 4 6 8 Price lid. I/- 1/2 1/6 2j- 21- 10/6 11/6 13/6 171- 2V- 23/- 2110 Bottles, square, polished sides and bottom, stoppered, as used for sugar samples. Capacity, 5 oz. 2111 Bottles, tube, stoppered, flat bottomed, clear glass, for specimens, etc. Size 2 by f 3 by I 3 by i 4 by I 4 by i Price .. 2/6 3/- 3/3 3/3 3/9 2112 Bottles, English moulded, for serum, etc., amber colour, 10 c.c. A2112 „ „ „ „ 20 c.c. 2113 Bottles, for serum, etc., clear glass, 10 c.c. . . A2113 20 c.c. . 2112 2113 £0 16 20 2/5 2/9 28/- 32/- standard 40 oz. 4/- each. 47 /- per doz .. per doz. £0 13 ( 5 by f 6 by i in. 3/6 4/3 per doz. per gross £0 9 I £0 13 ( £0 7 ( £0 9 I CROSS STREET- HATTON GARDETST E-C *" BAIRD &.TATLOCK (LONDON) LTD. ic.c. 2114-2115 2116 2c.c. 2117 Serum Bottles or Flasks of light blown glass, with long necks for hermetically sealing, special quality Jena glass for sterilising. Capacity . . . . i 2 3 5-10 20 c.c. 2114 Clear glass 6/- 7/6 8/- 9/- ll/- 14/- per gross. 2115 Amber glass .. 7/6 9/- 10/- ll/- 14/- 16/- 21 16 Bulbs or Ampoules for Vaccine, special Jena glass, with round bottom and drawn off to a point. Clear (A), green (B), blue (C), brown (D) glass. Capacity . . . . . . . . I 2 c.c. Price .. 3/3 3/9 4/6 per gross. 2117 Bottles, tube, with flat stoppers, squat form, of light glass. Capacity .. .. .. .. 8 15 30 c.c. Price . . . . . . . . 2/6 3/- 3/6 per doz. • 2118 2119A 2119B 2120 2118 Weighing Tubes of light glass, new form with caps ground to fit on the outside of bottle. Size No. . . .... i 2 3 4 2 by i 2 by if z\ by ij 3 by ij in. Price .. 8d. lOd. "lOd. I/- each. 7/6 9/6 9/6 1 1/- per doz. 2119 Bottles, weighing, stoppered, very light clear glass, flat bottomed (A or B form). Size . . ii by | 2 by i 2 by ij 2 by i£ i\ by i£ 3 by i 3j by ij in. Price .. ~6d. 7d. 8d. 9d. lOd. 8d. 1/1 each. . . 5/6 6/- 7/6 8/6 9/6 7/6 12/- per doz. 2120 Bottles, weighing, stoppered, very light clear glass, round bottomed. Size . . . . . . . . 3 by | 3! by | 3 by i 5 by f in. Price . . . . 5d. 6d. 8d. 8d. each. 4/6 5/6 7/6 7/6 per doz. [EMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 417 BAIRD &1ATLOCK (LONDON) LTD. 2121 2122 2123 2121 Bottles, weighing, squat form, stoppered. Diameter Depth Price 2 1} 1/9 2122 Weighing Bottles, globular form, stoppers carefully ground to fit. Capacity .... . . 50 Price .. •• •• •• •• •• I/- 2.1 in. 1-2 in. 2/6 each. 100 1/4 150 c.c. 1/6 each. 2123 Dr. Praussnitz's Weighing Cups or Basins. See Zeitschrift fur foren. Wissenscha/ten, .1894, and Zeitschriit fur Augen Chemie, 1894. Capacity . . . . . . . . . . . . 10 20 30 c.c. Price .. .. •• •• •• . . 8d. 9d. lOd. each. 2124 Dr. Praussnitz's Weighing Cups or Basins, with glass plate ground to fit. Capacity . . . . . • • • • • . . 10 20 30 c.c. Price .. .. •• •• •• •• Hd- I/- 1/3 each. 2125 2126 2128 10 3/. 12 3/6 16 pints. 41- each. 4 1/6 6 1/9 8 pint?. 2/- each. 2125s Stoneware Jars, with air-tight covers, suitable for storing dry chemicals. Capacity . . $123468 Price .. I/- 1/3 1/6 1/8 2/'- 2/2 2/6 2126s Stoneware Jars, with shut-over lids, for storing dry chemicals, etc. Capacity . . . . . . . . i 2 3 Price 9d. I/- 1/3 Bottles, Woulff's, best clear glass, welted necks ground inside. Capacity 4 8 12 16 20 24 32 48 64 100 160 320 oz. 2127 2 Necks 8d. lid. I/- 1/1 1/2 1/3 1/4 1/8 2/- 2/6 41- 8/- each. 2 Necks 7/6 10/6 ll/- 12/- 13/- 14/- 15/- 18/6 22/- 28/- 45/- 90/- per doz. 2128 3 Necks lOd. 1/2 1/3 1/4 1/6 1/7 1/10 2'- 2/6 31- 51- 91- each. 3 Necks 9/6 13/- 14/- 15/- 17/- 18/- 20/- 22/- 28/- 33/- 55/- 97/- per doz. CROSS STREET- HATTOTST GARDE1ST, E-C RAIRD &T&TLOCK (LOM)ON) LTD. 2129 2130 2131 16 1/6 24 32 2/6 2129 Bottles, Woulff's, with 2 necks and tubulurc at bottom. Capacity 4 8 Price lOd. 1/4 2130 Bottles, Woulff's, with 3 necks and tubulure at bottom „ I/- 1/6 2/- 2/6 3/- 3/6 2131 Bottles, Woulff's, with inlet and outlet tubes ground to fit, and middle neck stoppered. Capacity . . . . 4 8 12 16 24 32 48 Price .. 1/10 2/- 2/3 2/9 3/3 3/6 4/3 40 oz. 3/- each. 64 oz. 5/- each. 2132 2133 2134 2132 Bottles, tubulated (aspirators), of stout clear glass, tubulure at bottom, ground inside. Capacity . . Price Capacity Price 2133 Bottles, tubulated, of stout clear glass (aspirators), with stopper and stopcock ground to fit, Capacity . . . . i y\ 5 10 15 20 30 litres. Price 5/- 7/- 9/6 15/- 18/- 28/- 40/- each. 2134 Bottles, tubulated, of stout clear glass (aspirators), with stopcock ground to fit, Capacity .. .. I z\ 5 10 15 20 30 litres. Price . . . . 4/- 5/6 8/- 13/- 15/- 25/- 37/- each. lOd. i "/• 5/6 65/- 1/3 14/- 10 83/- l'/9 20/- 15 9/6 112/- 2 23/- 20 18/- per doz. 3 2/7 30/- 30 30/- 4 3/2 36/- 40 40/- 5 3/6 411- 50 50/- litres. each, per doz litres, each. 419 2 E BAIR-D &TATLOCK. (LONDON) LTD. 2135 2136 2137 2135s Bottles, stoneware, with stoneware stopcock ground in tubulure at bottom. 2138 i 6/6 2 7/6 Capacity A. Price B. Price without stopcock 2136s Acid Jugs, stoneware. Capacity Price 2137s Acid Jugs, guttapercha, with lip and handle. Capacity Price 2138 Specimen Cylinders, clear glass, on foot, upright stoppered. Capacity Price 4 10/6 6 13/6 8/6 2 9d. 25 7/6 8 18/6 10/6 4 1/3 i 4/9 50 10 gallons. 25/- each. 15/- „ 8 pints. 1/9 each. 80 c.c. ll/- per doz. 2140 2142 2144-2145 2146-2147 Bottles, iron, with screw stopper (mercury bottles), about J gal. capacity . . each £0 Bottles, pressure, in frame, with screw cap, for heating substances in bath, 125 cubic centimetres capacity . . . . . . . . . . . . . . each Extra Bottles, without frame, with glass disc Bottles, pressure, in frame, with screw attachment on neck . . . . . . „ Extra Bottles, without frame, with glass disc . . . . . . . . „ 2139 2140 2141 2142 2143 2144s Balls, cast iron, for bursting by expansion of water when frozen, with screwed stopper 2145s Extra Balls, without stopper 2146s Bottles, cast iron, for bursting, with stopper 2147s Extra Bottles, without stopper £0 £0 £0 £0 £0 £0 £0 £0 4 0 4 0 1 1 1 0 CROSS STREET • HATTOTST GARDETST, E-C 420 BAIRD &.TATLOCK (LONDON) LTD. 2148A 2148s !148 Bottles, sample tube, in cases. Size of metal case, 4^ by 2j by £$ in. A. No. 2 containing five tube vials, with vegetable ivory topped corks B. No. 6 containing six tube vials, stoppered . . . . .'. C. No. 20 containing twelve tube vials, corked, in two layers !149 Bottles, tin, for methylated spirits, etc. Capacity . . . . . . i pint Price 6d. i quart 7d. 4 gal. I/- 1150s Bottles, guttapcrcha, for fluoric acid, with stoppers. Capacity . . . . "' — i 2 4 Price .. .. 1/9 2/- 3/- 12 i gal. 1/6 16 2151 2152 2150 each !151 Bottles, clear glass, for specimens, with inverted stoppers ground in. Capacity about . . 2 4 8 12 20 30 Price .. .. 6/- 8/- 10/- 13/- 18/- 20/- £030 £046 £036 2 gals. 2/6 each. 32 oz. 9/- each. 40 oz. 30/- per doz. !152 Specimen Tubes, inverted, on boxwood bases. No. Height Diameter Price I 60 20 3/- 35/- 2 80 25 3/9 43/- 3 100 mm. 30 mm. 5/- per doz. 56/- per gross. !153 Bottles, clear glass, finest quality, for specimens, mushroom shape, stoppers ground in. Diameter . . . . . . . . . . 4 5j 6J in. Price .. 18/- 20/- 25/- per doz. 421 BAIRD &.TATLOCK (LONDON) LTD. 2154 2154 Bottles, tall show, with cut stopper and foot, best clear glass. Height, without stopper Height, with stopper Diameter of body of bottle Price 2155 Bottle, tall show, best clear glass. Height, without stopper Height, with stopper Diameter of body of bottle Price 2155 16 2\ 40/- ii in. 16 „ it,, 30/- per 13* in. 18 „ SOI -pet i Glass Cells, Boxes, 6?c. MADE OF SHEET GLASS, FUSED TOGETHER BY A SPECIAL CEMENT WHICH RESISTS THE ACTIONS OF ALL LIQUIDS. Special sizes made to order. ^fff^^jSSg^^ 2156s Glass Boxes, cube form, with cover. Size No. Height inside Width „ Depth Price I 30 30 30 2/6 2156 2 40 40 40 2/6 3 50 50 50 3/3 4 60 60 60 3/9 5 80 80 80 6 100 m.n 100 100 12/- eac CROSS STREET • HATTCflST GARDETST, E-C 422 BAIR-D &TATLOCK (LONDON) LTD. 2157 >1579 Glass Boxes, tall form, with cover. 2158 Size No. i 2 3 4 5 6 7 .8 9 10 ii Height outside 40 50 60 80 IOO IOO IOO IOO I2O 130 150 mm. Width inside 10 10 10 10 10 20 20 50 50 50 50 „ Depth „ 30 50 40 60 60 60 IOO IOO 120 130 IOO „ Price 1/6 1/9 2/6 31- 4/- 5/- 8/6 9/- 10/6 13/6 each. 2158s Glass Boxes, flat form, without covers. Size No. I ength outside Width inside Depth „ Price I 2 3 4 5 6 7 8 9 60 80 IOO 1 20 120 150 180 250 300 mm. 25 30 40 40 50 40 50 50 50 „ 25 30 4° 40 50 40 50 50 50 „ 21- 2/6 3/6 4/- 5/6 7/- ll/- 13/6 16/- each 2159 2160 2161 2159s Glass Boxes or Cells, suitable for spectrum analyses, etc. Size No. . . . . . . . . I 2 3 Height inside . . . . . . 30 75 50 Width „ . . . . ... 20 20 20 Back to front . . . . . . 4 4 10 Price • .. .. .. .. 31- 4/6 5/- 2160s Glass Boxes or Cells, square shape, for spectrum analyses, etc. Size No. Height inside Width „ .. Back to front Price 4 75 50 4 i 90 80 7 5 90 mm. 80 „ 10 „ 7/9 each. mm. 10 „ 7/- each. 2161s Glass Boxes, grooved for 3 by i in. microscope slides, with cover, suitable for staining mounted specimens. Size No. . . . . . . . . . . i 2 3 No. of slideb . . . . 4 5 6 Price . . 2/6 31- 3/6 each. ^CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 423 BAIRD &1ATLOCK (LONDON) LTD. 2162 2163 2162s Hollow Prisms of finest crystal glass, for all liquids, with carefully ground stopper. Size No. ...... i 2 3 Outside measurements . . 75 by 25 90 by 60 105 by 105 mm. Price .. .. .. ll/- IS/- 22/6 each. 2163s Glass Boxes with grooves for microscope slides, tall form, for staining mounted specimens. For six 3 by i in. slides £0 2164s Glass Boxes with grooves for microscope cover glasses f in. square. For six cover glasses, 3/6 ; for eight cover glasses . . . . . . . . . . £0 For other glass boxes, prisms, etc., see Catalogue of Physical Apparatus. 2165 2166 2167 2168 2169 2170 2171 2165 Carbonic Acid Apparatus, Fresenius or Parnell's .. 2166 „ ., „ Schrodter 2167 „ „ „ „ with tube to bottom 2168 „ „ „ Geissler 2169 „ „ „ Rohrbeck's, with tube to bottom 2170 „ „ „ „ 2171 ., „ „ Erdmann's .. 2172 „ ., „ „ with stopcock and tube to bottom 2173 Rose 2172 BAIRD &TATLOCK (LONDON) LTD. 2174 2175 2176 2174 Carbonic Acid Apparatus, Jones' (see Text-Book by Francis Jones, Manchester) .. £036 2175 Carbonic Acid Apparatus, with indiarubber ball, by slight compression of which the acid may be displaced. Boisterous evolution of the acid is avoided by its gradual dropping from the tube. Light and easily manipulated. The chief condition necessary being that only a small quantity of the acid be displaced at first . . . . . . . . £040 2176 Carbonic Acid Apparatus, as above, with drying-tube for acid and pumice, or for CaG.,. Tube at top of D must be closed momentarily with the finger when pressure on the india- rubber ball relaxes . . . . . . . . £0 5 0 2177 2178 2180 2181 3 4 5 6 8 10 12 in. 1 \ ! 1 i ij ,, 3d. 3d. 4d. 5d. 7d. lOd. 1/3 each. 21- 2/9 3/9 4/3 61- 9/6 13/- per doz. 2177 Chloride of Calcium U Tubes. Length of limb Diameter Price 2178 Chloride of Calcium U Tubes, with side tubes. Length of limb . . . . 4 5 6 8 Price .. .. .. 4d. 5d. 6d. 7d. 3/9 4/9 5/9 6/9 2179 Chloride of Calcium U Tubes, with tubes bent at right angles, ground to fit. Length of limb Diameter .. Price .. 3 9d. 4 \ I/- 1/1 1/3 8 t 1/6 10 lOd. 9/6 10 1 2/4 2180 Chloride of Calcium U Tubes, with carefully ground stoppers, drilled at side. Length of limb Diameter .. Price 6 f 2/3 26/- 8 i 3/- 35f- 1/5 1/7 1/10 16/- 18/- 211- 2181 Chloride of Calcium U Tube, new form with bulb and stoppers, drilled at side. Length of limb . . . . . . . . . . 4 5 Price .. .. .. .. .. .. 2/6 3{- 12 in. 1/2 each. 13/- per doz. 12 in. 3/- each 10 in. 3/4 each. 39/- per doz. 6 in. 3/6 each EMICAL AND SCIENTIFIC^APPARATUS AND PURE CHEMICALS. 425 BAIRD &TATLOCK. (LONDON) LTD. 2185 each, 7d. ; per doz. £0 6 k 8d.; £076 2182 2183 2184 2182 Chloride of Calcium Tubes, Marchand's form, two bulbs. 4 by £ in. . . 5 by § in. .. 2183 Chloride of Calcium Tube, improved by Fresenius. 4 by i in . •.. .. .. .. .. each, 8d. ; per doz. £076 5 by 1 in .. „ 9d.; „ £086 2184 Chloride of Calcium Tube, improved . . . . . . each £0 1 C 2185 Chloride of Calcium Tube, very light, with long limbs for successive sealings .. each £010 i 2186 2187 2188 2189 2186 Chloride of Calcium U Tubes, with bulbs. Length of limb . . . . 4 5 6 8 10 12 in. Diameter .. .. .. £ f f f | ij „ Price .. .. .. 8d. 9d. lid. 1/3 1/6 2/- each. 7 1- 8/- 10/6 14/- 17 /- 221- per doz. 2187 Chloride of Calcium Tubes, straight, with corks and small tubes in ends. 4 by f in. . . . . . . . . . .' . . . . . . per doz. £0 2 6 by fin. .. .. .. .. .. .. . . £03 2188 Calcium Chloride Tube, for combustions, devised by Arthur E. Hill, Esq. each, 1/2; per doz. £0 13 The tube consists of an inner tube (A) surrounded by a larger tube (B) fused to (A) at (D) and carrying a side tube (E) with the usual form of condensing bulb. To fill the apparatus, fine granular calcium chloride is introduced into both tubes (A) and (B), a little glass wool being previously inserted at the top of each tube. After filling, glass wool is again introduced, and a suitable cork inserted at (G). The cork is then cut off flush with the mouth of the tube and covered with sealing wax. The bulk of the water produced in the combustion is condensed in the bulb on the tube (E), the remainder being absorbed in its passage down the tube (B) and up through (A), thereby securing a double scrubbing action by the aid of a comparatively small quantity of calcium chloride A certain amount of space is allowed in the tube (B) immediately above the connection with (E) to permit aqueous vapour to diffuse before coming into contact with the calcium chloride. The whole apparatus only weighs from 25 to 30 grammes, and can be very easily emptied and refilled. 2189 Calcium Chloride Tube stoppered, new form .. .. each, 1/3; per doz. £0 14 CROSS STREET • HATTCTNT GARDEN, E-C- BAIRD &TATLOCK (LONDON) LTD. 2191 2192 2190 Chloride of Calcium Tubes. Length of tube A or B. Price with one bulb C or D. Price with two bulbs 2191 Chloride of Calcium Cylinders or Towers, with tubulure below. Height . . . . . . 8 10 Diameter . . . . . . i£ 2 Price .. .. I/- 1/3 2192 Chloride of Calcium Cylinders or Towers, with bored stopper and tubulure. Height . . . . . . 8 by ii 10 by 2 Price 3/6 " 3/9 4 2d. 6 8 2d. 3d. 10 in. 4d. each. 1/3 2d. 1/9 2/6 3d. 4d. 3/- per doz. 5d. each. 1/8 2/6 31- 41- per doz. below. 12 2 1/6 14 16 2J 2 1/9 21- 16 in. 2i ,, 2/6 each. jper and tubulure. 12 by 2 4/- 14 by 2 J 4/6 16 by i\ in. 5/- each. 2193 2194 2195 2193 Taeuber's Gas Drying Apparatus, consisting of four wash bottles and two chloride of calcium tubes on stand . . . . . . . . . . ..£186 2194 Harcourt's Drying Tube, on wooden foot . . . . . . . . • • each £020 The advantage of this tube is that the lower bulb is filled above the level of the side tube with HaSO.,,and the absorption of water by the acid in the pumice is shown by increase of volume ; the acid can be removed without taking the pumice out by pouring it off from the side tube. 2195 Gas Drying Apparatus, on stand £0 18 0 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 427 ^-*— /x e^5^ RAIRD &T\TLOCK (LONDON) LTD. •E 2196 2197 By George Stanley 2196 Gas Drying Apparatus, for use with a mechanical exhaust pump. Walpole, Esq. With stand It is found convenient in chemical laboratories to use a mechanical exhaust pump for many purposes, especially in conjunction with distillation apparatus. To maintain the pump in such a condition that at any moment it is capable of working at its maximum efficiency, it must be kept dry by use of either a steam-jacket or else an efficient drying apparatus interposed between it and the still. The accompanying drawing represents a form of desiccator which has been in use continuously for some months under somewhat severe conditions. The gases from the still pass directly down the tower (A). If the tap (E) be closed and (F) open, they pass through the concentrated sulphuric acid in the reservoir (B). This is the arrangement when the still is being exhausted at the commencement of distillation or when only a moderate vacuum is required. If the tap (F) is closed and (E) opened, the gases pass up the tower, meeting a slow stream of sulphuric acid running over the glass beads and regulated by tap (c). In this arrangement a short circuit is thus established which eliminates the hydrostatic pressure of the sul- phuric acid in the bottle (B), and there is no resistance offered to the gases passing to the pump. It is advisable to leave all taps turned off when the apparatus is not in use. The acid from (B) can be run out periodically, and if suitable, used again. 3197 Gas Drying Apparatus, with two calcium chloride drying towers, 16 in. high, two J-litre gas washing bottles, and two 12-in. U tubes, fitted with I.R. stoppers, and glass stopcocks as figured, on polished board A2197 Gas Absorption Apparatus (Potash) . . . , . . . . . . each The gas enters through the admission tube (A) into the potash lye in the interior of the apparatus, and passes through the " glass-wool " (B) saturated with potash lye. The latter is kept by spike-like glass projections (c) at some height above the potash lye below, so that undisturbed observation of the gas bubbles passing through is assured. The gas, completely freed from carbonic acid, takes its course through tube (D) and a thick layer of soda lime, with which the inner part of the apparatus is charged, to the exit tube (E) . The great length of this soda- line tube ensures, even with very rapid working of the analysis, the gas being completely dried passing from the potash lye. All the faults are avoided which are otherwise likely to occur if rubber or ground glass joints are employed. 2198 Gas Absorption Apparatus (Sulphuric Acid) . . . . . . . . each This apparatus serves for absorption of water, in place of the chloride of calcium tubes commonly used. The liquid is conveyed into the apparatus through tube (A), and only requires renewal after it has been used about twenty-five times. The interior (A) and (B) of the apparatus is filled with glass-wool, and as much sulphuric acid as will suffice for saturating the glass-wool. The bulk of the water formed is condensed in (A), and, after weighing, can be easily removed through the admission tube, in order to keep the sulphuric acid as nearly as possible anhydrous. £1 £0 16 3 £0 2 BAIRD &. TATLOCK. (LONDON) LTD. f 2201 2202 2199 2200 2199 Tubes, bent Y form, plain, 8 by £ in. 2200 Tubes, bent Y form, with stopcock, 8 by f in. 2201 Tubes, Reduction, hardest Bohemian glass, one bulb 2202 Tubes, Reduction, hardest Bohemian glass, two bulbs 2203 Clips, Mohr's, nickel-plated, for burettes, etc. No. . . . . . . i Length . . . . . . if Price .. .. .. ..3d. 2/3 2204 Clips, Mohr's, nickel-plated, with screw, 2\ in. long 2203 each 3d. 2/6 each, 6d. ; per dozen 8d.; 3 4 2| 3 in. 4d. 4d. each. 3/3 3/6 per doz. each 5d. ; per doz. £046 2205 2206 2207 2208 2205 Clips, Mohr's, nickel-plated, for burettes, etc., improved form, with catch to hold open. No. Price i 6d. 5/6 2 6d. 5/6 2206 Clips, Mohr's, for burettes, etc., with flat bar 2207 Clip, suitable for indiarubber tubing, up to f in. 7d. each. 6/6 per doz. each 4d. : per doz. each 7d. : per doz. £0 £0 3 9 6 6 2208 Clamps or Clips, nickel-plated, with screw for clamping, indiarubber tube, etc. Width inside . . . . • • i I I J Ji in- Price .. .. .. .. 5d. 5d. 6d. 6d. 7d. each. . . 4/9 4/9 5/6 5/9 6/9 per doz. 429 cr BAIRD &TATLOCK (LONDON) LTD. 1 2209 2210 2211 2213 2209 Clamps or Clips, nickel-plated, for indiarubber tube, the bottom part with hinge, enabling the removal without unscrewing. Size .. .. •• •• i I I i in. Price . •• •• •• •• 6d. 6d. 7d. 8d. each. ..5/6 5/9 6/6 7/6 per doz. 2210 Clamp or Clips, for indiarubber pressure tubing, etc., extra strong, with large screw and head, with movable hinge ; width inside, i^ in. . . 2211 Clips, Bunsen's .. 2212 Clamps or Clips for watch glasses, brass band form. Suitable for watch glasses . . diameter Price .. .. .. .. 2213 Clamps or Clips for watch glass, brass wire form . . each, 2/6 ; per doz. each 9d. ; per doz. £1 8 £0 8 2 4d. 5d. 6d. each. each £0 2214 No. i) 2214 (No. 2} 2214 (No. 3) 2214 (No. 4) 2214 Clamps, for burettes, condensers, etc., with right and left hand screw, and with malleable iron bosshead for fitting to stands, adjustable to any angle, clamps of gun-metal with iron rod for bosshead. Size No. . . . . . . . . i To hold tubes up to . . . . . . i Price, with bosshead . . . . . . 3/- . . 33/- 3 in. diameter 5/- each. 58/- per doz. No. 4 size is in malleable iron. See Retort Stands at end of Catalogue. BAIRD &1XTLOCK (LONDON) LTD. 2215 Clamps, as No. 2214, same pattern, but of superior finish, of polished gun-metal, lacquered. No. . . . . . . . . . . i 2 Price . . . . 4/6 5/6 each. 2216 Clamps (Size No. 3), same form as No. 2214, with adjustable jaw, suitable for holding tapering tubes, such as retorts, with bosshead . . . . . . . . . . each £056 2217 2218 2217 Clamps, with double jaws, size No. i (see No. 2214) 2219 £043 2218 Clamps, with jaw adjustable for any angle, fixed by pinching screw, size No. J (see No. 2214) . . . . . . . . . . ..£043 2219 Bossheads, malleable iron, with brass screws, for clamps Nos. 2214 and 2217. A. Small .. .. .. .. .. .. each, lOd. ; per doz. £096 B. Large .. .. .. .. .. .. ,,1/1; ,. £0 12 6 2220 2221 2223 II 2224 2222 each £020 £026 2220 Clamps, burette, plain, with spring 2221 Clamps, burette, jointed, with spring 2222 Clamps, double nitrometer, with right and left screws, and hook for suspending thermometer, made in gun-metal, with open bosshead to suit retort rods up to J in. diameter each £080 2223 Tube Holders, to fit on retort stands . . . . . . . . . . each £0 1 6 2224 Table or Support, 4 in. diameter, with boss to fit on retort stand each, 1/6 ; per doz. £0 17 6 BAIRD &TATLOCK (LONDON) LTD. 2225-2227 PROF. CARMODY'S COMBINED SHELF CLAMP (REGISTERED). 2225s Clamp of Malleable Iron, with pinching screw, A. . . each, 2/6 ; per doz. 2226s Retort Rings, with shank .. B. .. „ 6d. ; 2227s Iron Rods, with shank .. .. .. C. .. „ I/- ; The illustrations show how clamp and accessories may be adapted for various work, and the advantages are as follows : — 1. Fits shelves of any ordinary thickness. 2. Saves bench room. 3. The funnel ring slides horizontally in or out as required. 4. The vertical rod can be turned upwards above the level of the shelf, or downwards below it. In the former position it is more convenient as a burette holder ; in the latter for boiling flasks, water baths (conical especially), or ordinary retort rings. 5' Combines simplicity, strength, and portability. 6 Adapts itself to many common forms of subsidiary apparatus. 7. Can be unscrewed from shelf instantly and replaced in any other position. 8. Specially suitable for students' benches where space is limited, and for portable laboratory outfits. CROSS STREET • HATTOTST GARDETST, E 432 BAIR-D &TXTLOCK (LONDON) LTD. 2228 2231 2232 2233 2234 2235 228 Condensers, Liebig's, with tubulures on side, and indiarubber drawn over ends. Length of body . . . . 12 15 18 Diameter of body . . . . i| i£ i| Price complete " . . .. 2/- 2/3 2/6 229 Outer tubes only .. ... 1/3 1/5 1/8 230 Inner tubes only . . . . 8d. 9d. 9d. 231 Condensers, glass, spiral worm, large, on stand, 10 by 5 in. . . 21 24 3« 4J/6 in. ii each. 2/2 3/2 3/8 » 9d. 9d. 9d. » > • • • • • £0 12 6 232 Condensers, glass, spiral worm. Size 6 by i J 8 by ii 9 by ij 10 by 2 10 by 3 Price 2/- 2/6 " 3/- 3/6 4/- 233 Condensers, for fract. distillation, with outer and inner tube fused together. Size . . . . . . . . 10 12 16 Price .. .. .. .. 1/10 2/- 2/6 ii by 4 in. 5/- each. 234 Condensers, with flat inner tube fused to water jacket. Size Price 10 1/9 21 in. long. 3/6 each. 12 in. long. 2/9 each. :235 Condensers, Allihn's, all glass, inner tube a series of bulbs, and fused to outer tube. Size . . . . 8 10 12 16 20 in. long. Price . . . . . . 2/3 2/6 3/- 3/6 4/- each. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 4-33 RAIRD &TATLOCK (LONDON) LTD. 2236 2237 2238 2239 2240 2241 2236 Condenser, improved form, two concentric glass balls forming water jacket 2237 Condenser, inner spiral tube fused to outer tube. Size . . . . 8 10 12 Price .. .. ..4/6 5/- 5/6 16 2238 Condenser, Inland Revenue pattern, all glass, with spiral worm fused into jacket, each NEW FORM CONDENSERS. The essential part of these condensers is a hollow glass screw fitting closely over a plain tube, thus forming a spiral channel of about 120 cm. length through which the vapour is compelled to pass condensing on the wall of the inside tube. The disadvantage of the common spiral condenser, the gushing of the liquefied vapour, is entire!)' avoided as there remains still sufficient space between spiral and tube to allow the liquid to run straight down without stopping the passage. 2239 Condenser with inlet and outlet tubes fitted with corks 2240 Condenser made entirely of glass 2241 Condenser, similar in form to Cribb's condenser, but far more efficient 2242 Condenser, double surface with spiral £0 3 £0 7 £0 8 £0 11 /^— gst-jBF- ^— T / ™ T 2243-2244 2243 Condenser, Dr. Graham's, body 30 by i in., with side tubes, ordinary corks and adapter 2244 Condenser, same as No. 2243, with indiarabber corks . . each £0 2 £0 3 14- • CROSS STREET • HATTON GARDETST E- C BAIRD &TATLOCK (LONDON) LTD. 2245 2246 2247 2248 2249-2250 2245 Condenser, of metal, Prof. Storch's, nickel-plated copper, size 3 in. by i in., for use with Soxhlet's fat extraction apparatus, etc. . . . . . . . . . . each 2246 Condenser, all glass, with inside jacket for cooling water, 30 centimetres long . . „ 2247 Condenser, glass, double walled, for fractional distillation, as designed for use in Chemical Laboratory, King's College . . . . . . . . each, 1 /6 ; per doz. 2248 Condensers, Soxhlet's, double-ball, nickel-plated (condenser only) . . . . each 2249 Cribb's Double Surface Glass Condenser, 4f by ij in. 2250 Cribb's Double Surface Copper Condenser, 4^ in. by i in. 2251 New Double Surface Condenser. This condenser has been devised by us as an improve- ment on the ordinary pattern. It is entirely of glass and without corks or indiarubber connections to get out of order. As will be seen from the illustration, the cooling water enters by the tube projecting to the bottom. The exit tube is on the left. each 2252 New Double Surface Condenser, as above, of copper, nickel-plated 2251 £0 £0 2253-2254 2253 Condenser, Liebig's, copper jacket, 18 in. long, glass condensing tube 28 by | in., on iron tripod foot, brass pillar adjustable to various heights and to any angle 2254 Condenser, Liebig's, copper jacket, 24 in., glass tube 36 by ij in. each £0 17 £0 5 £0 4 £0 6 £0 £0 6 10 0 6 0 6 0 0 6 6 £0 15 £1 1 0 0 IEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 435 2 F BAIRD &. TATLOCK (LONDON) LTD. 2255 2256 2257 2255 Condenser, copper, Habermann's pattern, with a series of tubes for rapid condensing, inside cooling jacket, size of jacket, 12 by if in. .. 2256'1' Silver Flask, for pressure, about 150 c.c. capacity, with screw cap, for the estimation of esters, as used at the Government Laboratory, etc. Price about (See Journal of Society of Chemical Industry, 30th Sept. 1899, p. 868.) 2257'' Alcoholmeter, improved form (Manley's Patent, No. 20165). Latest pattern. For quickly and accurately determining the original gravities of beers after fermsntation. Price complete as illustrated. (Descriptive pamphlet on application) DESCRIPTION OF THE INSTRUMENT. Is the Condenser or Water Chamber. Is the Movable Scale from which the indicated readings are taken. Is the Boiler into which the sample to be tested is placed. Is the Thermometer tube containing mercury. During the operation the mercury rises in the tube and indicates the degrees of gravity lost during fermentation on the movable scale. Is the Thumbscrew by which the movable scale is adjusted for the time being according to the existent barometric pressure. Is the Spirit Lamp. Is the Standard Measure Glass. The Saccharometer for taking, present gravities. The Trial Jar for use with saccharometer. Small Set Screw for securely fixing the movaWe scate. Cover to put over lamp wick when not in use. £1 £3 7 18 £5 15 6 A. B. C. D. E. F. G. H. I. J. K. CROSS STREET • HATTOTST GARDEN, E-C 436 BAIRD &.TATLOCK (LONDON) LTD. 2259 2258 2266 2258 Dr. Thorpe's Revenue Still, as supplied to Inland Revenue and Custom House Laboratories, complete on stand, with burner . . 2259 Connecting tube, with glass balls, extra Thorpe's Revenue Still, No. 2258. Price of separate parts :— 2260 Brass stand, on lignum vitae sole 2261 Glass spiral worm condenser 2262 Distilling flask 2263 Argand burner, with steatite top and stopcock 2264 Bent glass tube, with indiarabber stoppers 2265 Beer Flasks, Bohemian glass, for Revenue Still 2266 Wine Flasks, Bohemian glass, for Revenue Still each each, I/- ; per doz. each each, 1 /- ; per doz. I/-: £2 £0 £1 5 £0 7 £0 11 £0 8 £0 1 £0 11 £0 11 0 0 0 6 0 6 6 0 0 BAIRD ^TATLOCK (LONDON) LTD. 2267 2268 Revenue Still as adopted by The Central Indian Excise Department (for use in Indian Custom Houses), the outfit consisting of Stand with spiral worm condenser, Jena distilling flask with connecting tube, flask with mark 100 c.c., pipette 50 c.c., special hydrometer 75-80° (Sike's scale), subdivided in 3^° and graduated cylinder 150 c.c. with special mark at 137.5 c.c. 2268s Automatic Water Distillation Apparatus of great efficiency, and small gas consumption. Made of copper and heavily tinned, it produces 20 litres of distilled water in 10 hours . „ . . . . £3 £600 2269-2270 2269s Copper Still with pure Tin Worm Condenser, in copper bucket, with brass screw head. Bottom of still spun in one piece, tinned inside. A. i gallon B. i „ ' C. 2 „ 2270s Copper Still with pure Tin Worm Condenser, as above, but with zinc bucket. A. i gallon B. i „ C. 2 2271s Condensers only, for above, with pure tin worm. A. i gallon .. .. .. .. .. zinc bucket, 13 /-; copper bucket B. i , 17/6 ; C. 2 „ 18/-; £1 £2 £3 £0 16 £1 1 £1 4 0 0 0 0 0 0 CROSS STREET • HATTCW GARDEN, E-C 438 BAIRD &TATLOCK (LONDON) LTD. 2272-2273 0 2272s Copper Still with pure Tin Worm Condenser, in copper bucket, fitted with con- stant level apparatus, connected from condenser to still with metal couplings, still- head fitted with brass screw, body of still spun in one piece and tinned inside. A. £ gallon . . B. i , C. 2 2273* Copper Still with pure Tin Worm Condenser, as above, but with worm in zinc bucket A. \ gallon . . B. i , C. 2 2274 2274s Copper Still with constant level apparatus, pure tin worm condenser in copper bucket with metal couplings. Still head fitted with brass screw, still tinned inside and body spun in one piece, mounted on stand. Price complete with paraffin burner as illustrated— A. \ gallon size .... B.I C. 2 £210 £2 18 6 £3 11 0 £1 18 0 £2 15 0 £350 £2 15 0 £3 12 6 £450 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 439 BAIRD &TATLOCKL (LONDON) LTD. 2275s Copper Stills, all brazed of heavy copper, with copper bucket, pure tin condensing worm, and constant supply arrangement. Sizes 4 gals, and upwards are fitted with heavy gun-metal collar with swing screws, to fasten stillhead. Capacity .... i 2 Price .. .. £4 10 0 £550 Capacity 15 Price £7 10 0 £12 10 0 (Any size made to order.) £5 12 £13 15 £6 0 £16 4 gallons. 15 0 each. 1 6 gallons. 16 0 each. WATER INLET\ GAS 2276 (Prices see page 441). 14- • CROSS STRET • HATTQN GARDEN, E-C 440 BAIR.D &.TATLOCK (LONDON) LTD. 2276 Copper Stills, all brazed, of heavy copper, with pure tin condensing worm in copper bucket, constant level arrangement from condenser to still. The still is mounted on a heavy sheet-iron jacket, which carries a series of Bunsen burners for heating the still. Capacity 2 4 8 12 16 gallons Price £750 £8 15 0 £14 10 0 £16 10 0 £19 10 0 2277s Copper Stills, as No. 2276, supplied for heating by means of coal or coke with fireclay-lined furnace, sheet-iron elbow, and 6-ft. chimney. c.-ipacity .... 4 8 12 16 gallons £9 15 0 £14 15 0 £18 5 0 £21 10 0 2278 2278' Copper Stills, brazed, of heavy copper, with pure tin worm and constant level arrangement from condenser to still on iron stand, with sheet-iron jacket and set of rose top burners. A. Water inlet. C. Constant level. B. Water pipe to constant level C. D. Exit pipe for the distilled water. Capacity . . . . . . . . 4 6 8 gallons. Price .. .. .. £11 5 0 £12 15 0 £15 10 0 Stills for the distillation of water for conductivity experiments, see Physico-Chemical section of Catalogue. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 441 BAIRD &.TATLOCK (LONDON) LTD. 2282 2279 2280 2281 2283 2283s Syphon Mercury or Oil Gauge for indicating and measuring small differences of pressure. Mounted on stand with millimetre scale 100 — o — 100, on opal glass, as illustrated. Without mercury 2284s Syphon Mercury Gauge, as above, with stopcock, on bent limb 2285s Syphon Mercury Gauge, as Fig. 2283, unmounted £0 £0 £0 2279s Mercury Vacuum Manometer, consisting of single tube and cistern with sliding meter scale graduated to read o to 760 cm. Mounted on stand with mercury vessel 2280s Mercury Manometer, as above, with syphon tube and cistern. Mounted on stand with sliding millimetre scale, as illustrated 2281s Compressed Air Manometer, simple form, with scale i metre long, zero in centre, short limb, with scale \ metre long 2282s Mercury Manometer, U tube form, for measuring the pressure exerted by a gas. The limbs of the manometer are 50 cm. in length. Mounted on stand with silvered millimetre glass scale, \ metre long, as illustrated . . . . . . . . . . . . £0 A2282S Plain Tube only, as above, with limbs | metre long . . . . . . each £0 B22825 Plain U-shaped Tube, as above, but i metre long . . . . . . „ £0 £0 £0 £0 4 6 7 0 0 CROSS STREET • HATTGTNT GARDETST, E-C 442 BAIRD &.TXTLOCK (LONDON) LTD. r - m 2289 2286 2287 2288 !286 Claison's Manometer, with cardboard scale. Price without mercury . . . . . . £0 15 0 !287 Anschiitz's Manometer, with movable white glass scale. Price without mercury . . £0 12 6 !288 Manometer on Board, with milk glass scale, division inches or millimetres, with stopcock in branch . . . . . . . . . . . . . . . . ..£066 2289 Manometer on Board, with milk glass scale, division inches or millimetres, with stopcock closing both branches ' . . . . . . . . . . . . . . . . £0 13 0 2290 2290° Copper Steam Jacketed Pans, for making emulsions, etc., as used in hospital dispensaries, tinned inside, with draining tap at bottom, and mounted on iron standards for tilting, one standard also carries the steam barrel with valve stopcock and short length of barrel ready for connection to steam pipe. Capacity i 3 5 8 10 12 gallons. Price £700 £8 10 0 £11 10 0 £12 10 0 £13 10 0 £15 0 0 Other sizes and special patterns can be supplied to crder. 2291-2292 229 11 Vacuum Distillation Apparatus, complete as figured, consisting of a heavy copper retort fitted with steam coil for heating, gauge and thermometer. Capacity 5 litres . . £20 2292' Vacuum Distillation Apparatus, as above. Capacity 7 litres . . . . . . £23 2293 2294 2293s Vacuum Evaporating Apparatus, consisting of porcelain basin with ground edge, 180 millimetres diameter, capacity ij litre, glass cover, with tubulure and ground rim, and copper water bath with stopcock on stand 2294s Vacuum Evaporating Apparatus as above, but with condenser, gauge, collecting vessel, and water pump, as figured 2295s Porcelain Basin, for above, with glass cover and distilling tube £2 15 £5 10 £1 1 CROSS STREET • HATTOTST GARDEN, E-C k-> . tA miam 444 RAIRD &TATLOCK (LONDON) LTD. 2296 2297 (Fig. A) 2297 (Fig. B) 2296 Flasks, with contracted necks for fractional distillation, with inner tube and rubber connections. 2297 Receivers for preserving the distillates, to be closed with the blowpipe. Capacity . . . . . . . . 15 30 Fig. A. Price . . . . . . 3/- 3/- Fig. B. „ .. .. ..3/3 3/6 Capacity Price i 7d. 8d. 4 9d. 12 1/3 16 1/6 24 1/9 32 oz. 2/3 each. 50 c.c. 3/6 per doz. 2298 2299 2300 2301 J298 Bruhl's Apparatus for fractional distillation with vulcanite holder for tubes. A. Small, with five tubes of 25 cubic centimetres capacity . . ' B. Medium, with five tubes of 40 cubic centimetres capacity C. Large, with five tubes of 80 cubic centimetres capacity 5299 Receiver, by Lothar Meyer (See Ber der. Chem. Ges., 1887, p. 1833.) !300 Bredt's Receiver, complete with flask, indiarubber stopper, condenser, and receiver J301 Receiver, alone, with tubes fitted £0 16 0 £100 £150 £0 10 0 £080 £050 445 BAIRD &L TATLOCK. (LONDON) LTD. o 2302 2303 2302 Flasks, Anschiitz, for distilling easily solidifying substances. Capacity . . . . . . . . 15 3° Price . . 6/'- 71- 50 23C4 100 C.C. 10/- per doz. 2303 Flasks, Anschiitz, with collar to prevent the return of the condensed product into the flask. Capacity . . . . . . . . 15 30 5» 100 c.c. Price .... 8/- 9/6 12/- 14/- per doz. 2304 Still Watcher, Mohr's, for indicating progress of distillation and density of liquid, on polished wooden foot . . 2305 Hydrometer for still watcher, 700 to 850 sp. gr. 2306 Copper Plates. £0 1 extra £0 6 by 6 6d. 9 by 9 1/6 12 by 12 in. 2/3 each. Indiarubber Stoppers. ILLUSTRATIONS FULL SIZE. CROSS STREET • HATTCflST GARDETST, E-C 446 BAIRD &L lATLOCK (LONDON) LTD. 2307 !307r Corks, red indiarubber, bung form, solid, one or two holes (illustrations are full size). Size A B C D E F G HIJKLMNOP 3 2j 2J 2J 2 i| i| ij if ij ij i J f I J in. diam. narrow end. 6/- 5/- 3/- 2/6 2/- 1/4 1/2 I/- lOd. 8d. 6d. 5d. 4d. 3d. 2d. 2d. each. 70/- 58/- 35/- 29/- 23/- 15/6 13/6 11^6 9/9 7/6 5/6 4/6 3/9 2/8 1/9 1/6 per doz. jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 447 BAIRD &TATLOCK (LONDON) LTD. 2308 Illustrations full size 448 BAIRD &.TATLOCK (LONDON) LTD. 2308' Corks, first quality red rubber, solid, i hole and 2 holes, Size No i 2 3 3a 4 same prices (illustrations are 4a 5 sa 6 full size). Narrow end a Tff i I A 1 a TF | ,','. } in. diam. Price . . Id. Id. Hd. 2d. 2id. 3d. 3d. 4|d. 6d. each. »> * • lOd. lid. 1/4 1/10 273 2/9 3/- 4/3 5/6 per doz. Size No. 6a 7 7a 8 8a 9 10 ii 12 13 Narrow end i » T'fV I i I* IT\ ij if If in. diam. Price . . 7d. 8d. 9d. lid. 1/3 1/5 1/10 2/7 3/2 5/- each. Jl • • 6/6 7/6 8/6 10/6 14/- 16/- 21/- 30/- 36/- 58/- per doz. (See page 448 for full size illustrations). 2309 2309 Corks, best selected quality, for bottles, specimen tubes, etc. 2310 Narrow end 1 I i lf ij if jj x| ij in. diam. Price . . . . 2d. 2d. 2d. 2Jd. 3d. 4d. 4Jd. 5d. 6d. per doz. „ 1/9 1/10 1/10 274 2/9 3/10 47- 4/6 5/6 per gross. Narrow end i| 2 2i 2i 2f 2£ 2J 3 3i 4 in. diam. Price . . 7d. 8d. lOd. l/- 1/1 1/2 1/6 1/9 1/10 2/6 per doz. „ 6/6 7/6 9/6 10/- ll/- 12/- 16/- 18/- 21/- 28 /- per gross. 2310s Corks, Asbestos, solid or one hole in centre. Top diameter . . . . \ Bottom diameter .... Length . . . . . . f Price .. 1/3 f 1/6 2/6 i in. 3/3 per doz. 2311 2311 Corks, finest picked quality, for chemical purposes (long form). i 4d. 3/6 I* 1/6 Long shape, narrow end Price ,> . . . . Long shape, narrow end Price 3d. 2/3 3d. 2/6 i 9d. lid. l/- TW ia. 3/3 if 1/4 H 5d. 4/6 it 1/8 8/6 10/6 11/6 15/- 17/- 19/- 5/6 1/9 20/- 7d. 2 If- 22/- 2312 Corks, flat shives as No. 2309, with boxwood tops, suitable for sample bottles, etc. Diameter of shive .. i ij ij i| Price 9d. 8/6 l/- ll/- 1/3 14/- 1/6 17/- 2312 |- in. diam. 7d. per doz. 6/6 per gross. 2^ in. diam. 2/6 per doz. 28/- per gross. 2 in. 1/9 per doz 20 /- per gross. 449 BAIRD &TATLOCK (LONDON) LTD. 2313 2314 2315 2316 2317 2313 Cork Borers, in sets, steel nickel-plated, with separate handle fitted to each borer. Sets of Cutting edge Price 1-3 1-6 5 to 7 5 to ii 5 to 15 91- I-I2 5 to 19 12/6 1-18 5 to 26 mm. ' 23 /- per set 2314 Cork Borers, in sets, Sets of brass nickel-plated, with rod. i-9 I-I2 1-18 Cutting edge Price 5 to 7 5 to ii 1/2 2/3 5 to 15 3/6 5 to 19 5/- 5 to 26 mm. 11/6 per set, 2315s Apparatus for boring indiarubber corks, with set of 14 nickel-plated cork borers, to bore holes 3ff to i in diameter . . . . . . . . . . . . ..£11 2316 Cork Borers, brass, cheaper form for students' use. Sets . . . . . . 1-3 Price .. .. .. 8d. „ . . . . . . 7/6 2317 Cork Borer Sharpener, brass, with strong steel knife 1-6 1/6 per set. 17/ - per doz. sets. each £0 2318 2318 Cork Pressers, bronzed iron 2319 £0 £0 2319 Cork Presser, to take corks up to ij in. diameter Press the handle downward and the cork will roll along the jaw from right to left, being pressed and sofi i for insertion into the mouth of the bottle. By raising the handle the cork is released and automatically th >vi out. CROSS STRET • HATTON GARDETST E-C 450 BAIRD &TATLOCK (LONDON) LTD. 2320 2321-2324 !320 Covers, glass, concave, for beakers, etc., with slit at side. Diameter .. .. .. •• 3 4 5 'n- Price . . . . . . 5/6 7/- 8/- per doz. See also Glass Discs and Watch Glasses. » !321S Models of Crystals, glass, 20 models, 3 centimetres M22 Models of Crystals, wood, 20 models, 5 centimetres !323= Models of Crystals, wood, 40 models, 5 centimetres !324S Models of Crystals, wood, 60 models, 5 centimetres 2325 2326 2327 (Sizes ooo-oo) 2327 (Sizes 0-5) £325 Capsule, Meissen porcelain, flat bottom, thin, diameter if in., height I in. 2326 Capsule, Royal Berlin Porcelain, round bottom. Diameter .. .. .. i i§ if 2 Price .. .. .. 2/34/8 5/6 7/- £176 £110 £220 £330 2328 . . per doz. £0 2| 2Jf in. 7/6 8/9 per doz. No. Diameter Capacity A. Price, without lid B. „ with lid 2328 Crucibles, Meissen porcelain. No. .. ..9 Capacity . . • • I A. Price, with lid . . 6d. 5 0 2327 Crucibles and Lids, Royal Berlin Porcelain, with Government Trade Mark in blue (see illustrations). ooo i 2/8 8 i oo T 4/6 6/- o Ii i 5/6 i if I 7/3 101- 6 i 2 3 2 4 3 5 3i 8 in. oz. 10/~- 11/9 14/6 16/3 per doz. 12/9 14/6 19/- 20/9 M 3 t 3* 2 5 I 8 o ii OZ. B. Price, without lid 6d. 6d. 8d. lOd. lid. 1/1 1/3 1/6 2/- each. 5/6 5/6 5/6 7/6 9/6 10/6 12/- 14/- 17/- 23/- per doz. 5d. 5d. 5d. 7d. 9d. lOd. I/- 1/1 1/4 1/10 each. 4/6 4/6 4/6 6/6 8/6 9/6 ll/- 12/- 15/- 21/- per doz. 2 G BAIRD & lATLOCK (LONDON) LTD. 2329B 2329A-2330 2332 2333 2336 2338 2329 Crucibles (Rose's), porcelain (A), with cover gas leading tube (B), Royal Berlin . . each £0 2 2330 Crucible (Rose's), Royal Berlin Porcelain, with cover only 2331 Tube, with flange for Rose's Crucible 2332 Crucible (Gooch's), Royal Berlin Porcelain, with perforated bottom. Capacity . . . . • • 35 25 IO Diameter at top . . . . 40 35 27 Height . . . . 43 4<> 3« Price .. .. .. 1/2 1/1 lOd. 12/9 11/9 9f- £0 6 20 30 8d. c.c. in in. mm. each. 7/3 per doz. 2333s Indiarubber Cones, with glass filtering tube for use with Gooch's Crucibles, No. 2332. 35 9d. 8/6 2334T Crucibles, fireclay (London rounds) . No. Height Price i 2| 8d. 8d. lid. 8d. 3 3i 3t 3f 1/3 1/9 I/- 1/3 4 4 21- 1/3 4J 4* 2/5 1/6 2335T Crucibles, fireclay, triangular. No. Height Price i If 6(1. 8d. 7d. 8d. 8d. lid. lOd. lid. 2336 Nickel Crucibles. Diameter . . Price .. 2337 Nickel Lids, to suit, price I 1/1 6d. 25 10 6 c.c. crucibles. 9d. 9d. 8d each. 8/6 8/6 7/6 per doz. 5 51 6 6J 7 8 9 10 5 6 71 8J I0i in. 31- 3/8 4/2 6/- 7/4 9/2 12/6 18/- per doz. crucib 1/10 1/10 2/5 2/6 31- 3/6 41- 4/9 per doz. lids. 2 2^ 3 31 4 4| 2| 31 3f 31 4 in. l/- 1/1 1/3 1/6 2/3 2/9 per doz. crucib 1/2 1/2 1/6 1/6 1/10 1/10 per doz lids. if if 2 2f in. 1/3 1/5 1/8 21- 8d. lOd. lOd. 1/1 2338s Salamander Crucible Jackets, for heating crucibles, with three ledges inside jacket to support crucible. Price with cover . . . . . . each, 4/- ; per doz. £2 6 0 CROSS STREET - HATTOTST GARDE1ST, E-C 452 RAIR.D &TATLOCK (LONDON) LTD. 2339 2339 Crucibles, cast-iron, with cover. Diameter Height Each 2340 Crucibles, spun iron, with cover. Diameter Height Each 2341 Crucibles, spun copper, with cover. Diameter . . Height Each 2340-2341 2f l3/' 3 4 1/6 3i in. 24i " If If 3 1/2 4i in. 2j ,, 1/6 2 3i in. 23 ^f >, 1/6 PLATINUM APPARATUS. Prices variable according to fluctuations of the Market. Present price submitted on application. 2342A 2342T 2342 Platinum Crucibles, with lids A or B. otherwise ordered.) (Approximate price, 212/- per oz. troy.) 2342B (These are always supplied with flat lids (Fig. 2342A) unless — . Size No. Capacity. Height. Diameter. Apprcx. Weight. Size No Capacity. Height. Diameter. Apx. Weight. Ctv Oz. Troy. grms. Troy. grms. 12 100 C.C. 6.5 c.m. i 6 c.m. 3-25 100 6 30 c.c. 4 C.m. 3.6 c.m. I 31 II 80 „ 5-5 » j- 2.6 80 5 25 „ 3-8 „ 3-4 -. 0.8 24 10 50 „ 5 „ 4-4 „ 1-7 52 4 20 „ 3-4 .. 3-2 „ 0.7 21 9 45 „ 4-8 „ 4-3 „ 1-5 46 3 15 „ 3-3 - 3 „ 0.5 16 8 40 „ 4-5 „ 4 „ 1-3 40 2 12 „ 3-i ,. 2.8 „ 0.4 12 35 ,, 4-3 „ .3-8 „ I-I.5 36 I 10 „ 2.7 ,, 2.6 „ 0.3 9 453 BAIRD &TATLOCK (LONDON) LTD. 2345 (Approximate price, 212/- per oz.) Platinum Crucibles (Gooch's), 20 c.c., i.o oz. troy = 30 grammes „ „ 30 c.c., 1.3 oz. troy = 40 grammes „ 40 c.c., 1.7 oz. troy = 50 grammes Sieve, Loose, for Gooch's crucible 2344 2342BT Platinum Capsule Cover. 2344' 2346 2347 2345* 2346' 2347' A. „ „ „ 30 c.c., 1.3 oz. troy = 40 grammes | Approximate B. „ „ 40 c.c., 1.7 oz. troy = 50 grammes I price, C. Platinum Sieve, Loose, for Gooch's crucible 230/- per oz. D. Platinum Cap for bottom of crucible Crucible, specially light, with cover, 30 centimetres, 0.8 oz. troy = 25 grammes. (Approximate price, 230/- per oz.) Platinum Crucible for alkali determinations, Lawrence Smith's, with cover, 8 centimetres high, 18 millimetres diameter at top, weight about 35 grammes. (Approximate price, 212/- per oz.) Platinum Crucible, tubulated Gooch form. Total length 95 millimetres, diameter 18 millimetres, weight 70-75 grammes. (See United States Geological Survey Bulletin, No, 305, 1907.) (Approximate price, 230/- per oz.) 2348' 2348 Platinum Basins, with spout. (Approximate price, 212/- per oz.) SIZES AND APPROXIMATE WEIGHTS. 2349 Capacity. 600 cubic centimetres. 500 250 175 100 70 60 50 30 A2348T Platinum 'Basins 23491 Platinum Filter 260/- per oz.) Approximate Weight. 6.5 oz. troy = 200 grammes. 5.5 „ = 170 3.0 „ = 90 = 60 Diameter. 13.0 centimetres. 12.5 10.0 2.0 1.2 37 28 0-75 „ 0.60 „ 0.50. „ without spouts. Capacities and weights as above (No. 2346). Cones, 10, 12 and 15 millimetres diameter. (Approximate 24 18 = 15 7-5 7.0 6.25 5-75 5-0 price, CROSS STREET • HATTON GARDEN, E-C 454 Iff BAIRD &TATLOCK (LONDON) LTD. 2350 2351 2352 2350T Platinum Dish, specially designed for water analysis. Capacity 100 cubic centimetres, weight about 20 grammes. (Approximate price, 230/- per oz.) 235 1T Platinum Dish, for milk analysis. Capacity 45 cubic centimetres, approximate weight 18 grammes. (Approximate price, 212 /- per oz.) 2352r Platinum Dish, for sugar analysis. Capacity 20 cubic centimetres, approximate weight 10 grammes ; capacity 25 cubic centimetres, approximate weight 12 grammes. (Approximate price. 212/- per oz.) 2353 2353T Platinum Incinerating Pans. Capacity 50 by 38 millimetres, approximate weight 18 grammes. (Approximate price 212 /- per oz.) 2354 2355 2356 2354T Platinum Spoons, for qualitative analysis, weight about 1.5 grammes. (Approximate price, 220 /- per oz.) 2355T Platinum Deflagrating Spoons. (Approximate price, 220/- per oz.) Bulb diameter . . . . . . § f f in. Without cover, approximate weight . . 2.4 3.5 6.5 grammes. With „ „ „ .. 3.5 4.6 7.8 2357 23571 Platinum Spatula (Approximate price, 220/- per oz.) CHEMICAL AND SCIENTIFIC APPARATU AND PURE CHEMICALS. 455 BAIRD &TATLOCK (LONDON) LTD. 2358 2358T Platinum Spatula in ebony handle . . Price 212/- per cz. (approximate B2360 2359T Platinum Spatula with cup end. 0.8 to i oz. = 24 to 30 grammes 2360T Platinum Spoons. 0.25 oz. = 8 grammes A2360T Platinum Spoons. 0.08 oz. = 2.5 grammes B2360T Platinum Boats. 0.18 oz. = 5.5 grammes c2360T Platinum Boats. 0.185 oz- = 5-75 grammes Any Size Made to Order. C2360 Price by weight per oz. appr „ 215/- „ „ 2201- „ „ 220/- ,. „ 220/- „ „ 220/- 2361 2363 2361T Platinum Boat, perforated at bottom, as used for steel analysis, with porcelain holder. (Price varies according to the market rate of platinum, about 230 /- per oz.) 2362T Platinum Boat, perforated at bottom for steel analysis, with platinum holder. Weight 38-40 grammes, at about 225 /- per oz. troy. 2363T Platinum Muffles. Price per oz. troy, about 212/- 11 centimetres long, 5 centimetres wide, 3.5 centimetres high. 1.5 oz. = 46 grammes. 12 „ „ 7 „ „ 5-0 „ 2.5 „ = 78 Any other sizes to order. CROSS STREET • HATTCXN GARDETST, E-C 456 BAIRD &TATLOCK (LONDON) LTD. .u 2364 !:>4T Platinum Sheet, perforated. Price per oz. troy, about 225 /- 3j in. wide. No. 6 gauge. 0.14 oz. = 4.4 grammes per sq. in. 3i ,. .. » 4 .. 0.13 „ = 3 Weights given are approximate only. 2365 2366 65r Platinum Gauze. Price per oz. troy, 2221- to 232/-, according to mesh. 2367 WiH+h Weight per sq. in. VV Li 1 1 1 1 . Troy. Gramme. 6 in. IOO 0.02 0.6 6 „ 42 0.02 0.6 I0j ,, 42 O.OO7 O.2I 6 „ 38 0.016 0.48 7 ,, 36 0.058 1.74 12 „ 36 O.OI7 0.51 4 » 36 0.017 0.51 41 „ 36 0.006 0.18 6 „ 32 0.016 0.48 6 „ 32 O.OII 0-33 3 „ 32 O.OII 0.33 3 ,, 3« 0.006 0.18 - 166T Nickel-plated Ring with Boss for platinum triangle. Screwed hooks for holding platinum triangle are made of nickel. Size of ring 4^ in. ; price of ring S671 Platinum Triangles. Approximate weight L1""'8'c alc uioitc ui lucKei. oiic ui mig 42 iii. , puce ui i"ig Platinum wire extra, price according to weight 207/- per oz. (approximate). 'r-s— «'— Twisted ends. (Price per oz., about 210 /-) ij if if 2 2| in. 8 ._io __ii_ _ _i^ 15 grammes. £076 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 457 . BAIRD ^TATLOCK (LONDON) LTD. Platinum Apparatus for Electrolysis. Price per oz. troy, about 215/- 2368 0.8 oz. 24 grammes. 2369 0.5 oz. 16 grammes. 2370 0.5 oz. 16 grammes. 2371 0.5 oz. 1 6 grammes. 2372 0.5 oz. 16 gramme 2373 2374 2375 0.6 oz. = 18 grammes. 0.9 oz. = 27 grammes. 0.3 oz. = 9 grammes per pi Nos. 2368, 2369, 2370, 2372, with roughened surface to order — extra charge, l/- W eights given are approximate only. Any special form of platinum apparatus made to order. CROSS STREET • HATTON GARDETST, E-C 458 RAIRD &IATLOCK (LOM)ON) LTD. ROTATING ELECTRODES OF PLATINUM. 2376 2377 2378 2379 ~ ~~~~'^'' J 2380 (See page 460 for prices.) 2381 459 BAIRD &TATLOCK (LONDON) LTD. a u Rotating Electrodes of Platinum, various patterns at 220 j- per oz. troy with addition for manufacture. Price variable according to market price of platinum. 2376T At 220/- per oz. troy + 35/- per oz. for manufacture. Approximate weight if — 2 ozs. per pair. 23771 2378T 2379T 2380' 238 V +. 291- + 291- + 101- + 291- + 35/- i oz. ,, i oz. \ oz. each. I oz. „ 2 — 2j ozs. per pair. Illustrations, see page 459. 2382 2383 2382T Rotating Electrodes of Platinum. Approximate weight ij oz. per pair, 255 f- per oz. 2383s Stand with rotating electrodes, consisting of heavy sole, brass upright with adjustable ring, one movable clamp for the fixed cathode, and one movable clamp with pulley and chuck ...... £21 A2383 B2383 A2383 Spring Forceps with platinum points, price variable B2383 Tongs, Crucible, pure nickel, 8 in. with platinum points, price variable c2383 Tongs, Crucible, gun-metal, 8 in. with platinum points, about, each £0 10 about £0 19 5 £0156 CROSS STREET • HATTCTH GARDETST, E-C 460 BAIR-D &TATLOCK (LONDON) LTD. Apparatus manufactured of Pure, Transparent Silica, for use at high temperatures. In addition to the ordinary forms of Laboratory Apparatus shown on following pages, we can now supply in Quartz Glass special and complicated pieces to almost any design. This apparatus is manufactured by a process which has the merit of producing articles of a symmetry hitherto nattuined in silica ware. The apparatus being transparent, and consisting of pure silica in a thoroughly fused and homogeneous condi- i)ii, fulfils purposes for which the ordinary opaque material is unsuitable. To those unacquainted with the properties of fused silica, the following may be of interest : — It does not crack on subjection to the most violent and sudden changes of temperature. It is unattacked by the volatile acids, with the exception of hydrofluoric acid. 1 1 lias a melting point approximately equal to that of platinum. It is harder than ordinary glass. Above i,ooo°C. it is permeable to hydrogen and certain other gases. Its co-efficient of expansion is .00000059 per degree Centigrade (about TV °f that of platinum). Its expansion, up to 1,000° C., is regular ; above 1,200° C. it contracts. Its density is 2.2 (approximately). See pages 462-466 for prices. 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 461 BAIRD &. TATLOCK (LONDON) LTD. 2384 2384T Basins, evaporating, deep or shallow form, of transparent silica. Diameter 38 5° 65 75 Price 71- 8/- ll/- 15/6 9° 201- 100 27/6 125 mm. 32/6 each. 2385 2385T Beakers, plain or with spout, of transparent silica^ Capacity ...... 50 75 100 c.c. Price . . . . . . 20/- 25/- 35/- each. 2386T Boats, for Combustions, of transparent silica. Size . . . . . . 2 by ^ 2| by & 3 by Tsv in. Price .... 5/- 6/3 7/6 each. 23871 Condensers, Liebig's, inner tube only of transparent silica. Size of inner silica tube 10 by f 12 by f 16 by | 10 by J 12 by i Price .. .. 7/6 9/- 12/- 12/- 15/6 16 by J in. 20/- "each. CROSS STRET • HATTOTST GARDEN, E'C 462 BAIRD &.TATLOCK (LONDON) LTD. 2388-2391 2388T Crucibles, tall, or short wide form, of transparent silica. Capacity Price 10 15 7/T 2O 10/- 30 14/- 40 16/- 18/- 75 22- IOO C.C. 26/- each. 2389T Covers for above, tall form, of transparent silica. Price .. .. 2/- 2/6 3/6 23901 Covers for above, wide form, of transparent silica. Price .. 3/- 3/9 5/3 10/- 111- each. 6/- each. 2391T Covers for Crucibles, with hole and gas leading tube (Rose's pattern) of transparent silica. For Crucibles of . . 10 15 20 30 c.c. capacity. Price .. .. 7/- .9/6 10/6 11/6 each. 2392 2932T Flasks, with ordinary or short wide neck, round or flat bottom, of transparent silica. Capacity . . 25 50 100 150 200 250 500 700 i.ooo c.c. Price 6/6 100 13/- 19/- 251- 30/- 40/- 50/- 60/- each. 463 BAIRD ^lATLOCK (LONDON) LTD. 2393T 2394' 2393 Flasks of transparent silica with ground stoppers. Capacity 25 50 too 150 200 Price 7/6 9/6 24/- 25 /- 32/6 250 40 /- 500 50/- 700 62/6 Flasks, distilling, with side tube fused on n?ck, of transparent silica. Capacity 25 50 100 150 200 250 500 Price 7/6 9/- 16/- 23/- 30/- 38/- 46/- 1,000 C.C. 75/- each. 1,000 c.c. 66/- each. 2395 2395T Retorts, plain, of transparent silica. Capacity . . . . . . . . . . . . . 5° Price .. .. .. 201- With tubulure and stopper ground to fit, 10/- to 15/- extra. 200 C.C. 50/- each. 2396T Test Tubes, of transparent silica. Size 100x10 100x12 125x12 100x15 125x15 150x15 125x20 150x20150x25 Price 21- 2/6 4/6 23971 Tubing, thick walls of transparent silica. Internal diam. 3 5 6 10 12 Price 4/2 5/2 6/3 8/4 16/3 2398T Tubing, medium walls, of transparent silica. Internal diam. 3 5 6 10 12 Price 5/r 15 20/3 15 5/6 20 22 25 mm. 25/- 62/6 93/9 per 30 cm. length lengths up to 50 20 22 25 mm. 3/4 4/2 51- 6/8 13/- 16/3 20/- 50/- 75/- per 30 cm. length lengths up to 50 i 14 -CROSS STREET • HATTOTST GARDEN, E'C 464 RAIRD &T&TLOCK: (LONDON) LTD. 9- 23991 Tubing (capillary), of transparent silica. Outside diameter . . . . . . . . 3 5 Price 12/- 24/- In lengths exceeding 18 in. 50 per cent, extra. Lengths of less than 6 in. will be priced as 6 in. lengths. 24001 Rod, of transparent silica. Size Price A 6d. A * A 1/3 2/6 7/6 In lengths exceeding 18 in. 50 per cent, extra. Lengths of less than 3 in. will be priced as 3 in. lengths. 7 mm. 30/- per foot. £ in. diameter. 12/6 per foot. 2401 2401T Triangles (solid rod), of transparent silica. Size Price 2492T Fibre, spun, various thicknesses, of transparent silica T 3/9 I* 2 in. 4/6 5/6 per gramme £060 2403 2403T Lecture Demonstration Set, consisting of one 50 cubic centimetres flask, one 10 cubic centimetres crucible, one triangle for ditto, one test tube 4 by f in., 12 in. Tsff in. tubing, of transparent silica Prices for larger or intermediate sizes will be quoted upon application. £100 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 465 BAIRD &TATLOCK (LONDON) LTD. 2404 2404T Weight Thermometers and Ignition Spoons, of quartz glass (transparent). Price of Weight Thermometers of the type illustrated, 4^ in. long over all . . . . per doz. £1 Owing to the fact that this material does not crack under the most violent changes of temperature, a Weight Thermometer made from it may be used without the risk of cracking — common to all other glasses when a liquid is introduced into a hot tube. This advantage over even the best glasses known prior to the adoption of quartz glass will be much appreciated by all who use, or direct the use of, Weight Thermometers, Ignition Spoons, and other forms of laboratory apparatus. 2405T Quartz Glass Ignition Spoons were originally designed for simple qualitative and quanti- tative ignitions, but other uses will readily suggest themselves. Price of Ignition Spoons, as illustrated, 3 in. long over all . . . . . . . . . . per doz. £0 2406 A2406 2406T Pyknometer Tubes of Transparent Silica in various forms as illustrated . . each £0 2 A2406T Parting Set, for Assays, with 13 Cups, as illustrated . . . . . . ..£118 CROSS STREET • HATTOTST GARDETST, E- C 466 BAIRD &.TATLOCK (LONDON) LTD. Apparatus made of Opaque Fused Silica. Silica Combustion tubes and boats. Plates as a substitute for wire gauze — save 25 per cent, in time of heating „ Triangles, with or without nickel or iron wire. Pyrometer tubes. „ Inner tubes for condensers. They will stand a temperature of over 1,200° C. Unaffected by extreme change of temperature. Acid proof. They effect a great economy in gas and in time. Rapid readings with pyrometers. 24071 Silica Tubes, opaque, open both ends. *!N LENGTHS UP TO 8 FEET = 244 Centimetres. Bore. Bore. Price Bore. Bore. Price Inches. Millimetres. Per Foot. Inches. Millimetres. Per Foot. A— A I 2 64. H 17—18 3/9 i 3 lOd. I 19 4/2 A 4—5 1/4 1 22 4/7 6-7 1/10 i 25 5/- A 8 2/2 4 28 — 29 5/4 1 9 — 10 2/6 4 31—32 5/8 TV ii 2/9 if 35 61. 1 12 — 13 3/- 4 38 6/4 8 TUT 14 3/2 it 4i 6/8 1 15—16 3/4 if 44 71" Tubes closed one end ^ to i in. bore, 4d. to 1/9 per tube extra according to size, * Lengths of less than i ft. (30 cm.) 10% extra. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 467 2H BAIRD &TATLOCK: (LONDON) LTD. 24081 Silica Rods, opaque. -In LENGTHS UP TO 8 FEET = 244 Centimetres. Diam. Millimetres. Price Per Foot. | 3 iy- f 4—5 6-7 1/6 ay- J6 8 2/4 I 9 — 10 2/8 24091 Silica Pyrometer.Tubes, opaque. •Lengths of less than I foot (30 centimetres) 10 per cent, extra. 2410T Silica Triangles, opaque. LENGTH OF SIDE. PRICE EACH. Inches. Millimetres. Iron. Silica Covered. Nickel Silica Covered. All Silica. Ii 38 3d. 4d. 1/6 If 45 3d. 4d. 1/6 2 5i 3d. 4d. 1/6 3* 57 4d. 5d. 1/9 a{ 63 4d. 6d. 1/9 2j 70 5d. 7d. ay- 3 76 5d. 7d. ay- 241 1T Silica Combustion Boats (without handle), opaque. • *!N LENGTHS UP TO 5 FEET = 152 Centimetres. Bore. Bore. Price Bore. Bore. Price Inches. Millimetres. Per Foot. Inches. Millimetres. Per Foot. i 3 il- 9 TV 14 3/6 H T^ 4—5 i/6 15—16 3/10 i 6-7 21- ii 17—18 4/4 A 8 2/4 f *9 4/10 1 9 — 10 2/9 5 22 5/4 Tff ii 3/1 I 25 5/10 i 12 — 13 3/4 INSIDE MEASUREMENTS. No. Length. Inches. Width. Inches. Depth. Inches. Length. Millimetres. Width. Millimetres. Depth. Millimetres. Price Each. O.I If i 5 Tff 44 12 8 l/- 0.2 3 4 T6* 76 12 8 1/6 0-3 3 ' 1 f 76 16 10 1/9 0.4 4 I Iff 100 18 12 2/3 0.8 2| i T6TT 70 10 8 1/6 CROSS STREET • HATTQT* GARDEN, E;C 468 BAIRD &TATLOCK (LONDON) LTD. BASINS. Made of Pure Fused Opaque Silica. 2412 Silica Basins are not attacked by acids. The large Basins provide a new and invaluable article for chemical manufacturing processes. Special Basins for the concentration of sulphuric acid. No corrosion. No breakage owing to extreme change of temperature. They can be exposed directly to the fire gases. Long life. Great saving in expenses of supervision. The rate of evaporation can be greatly increased. Basins of all sizes for research work and for the preparation of pure substances. An improved substitute for porcelain at comparable prices. iU2T Silica Basins, opaque. INSIDE MEASUREMENTS. No. Diameter. Depth. Diameter. Depth. Price Each. Inches. Inches. Millimetres. Millimetres. B. ii 51 2| 137 57 5/9 B. 12 54 2* 130 64 6/- B. 13 6 2* 152 64 6/3 B. 15 6 3 15? 76 7/- B. 17 7 2j 178 70 7/6 B. 19 7 si 178 95 7/9 B. 21 8 3* 203 83 8/9 B. 23 8 4f 203 co8 10/- B. 25 9 3* 229 89 11/3 B. 27 9 4i 229 121 12/6 B. 29 I2i 5i 3ii 133 18/9 B. 31 151 4 394 IO2 22/6 B. 33 18 7 457 I78 26/6 |j| |CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- [fjj 469 BAIRD &TATLOCK (LONDON) LTD. 2413T Special Silica Basin, opaque (for sulphuric acid concentration). (See Fig. No. 2412, page 469). . BENKER-HARTMANN CASCADE PROCESS. No. INSIDE MEASUREMENTS. Price Each. Diameter. Inches. Depth Inches. Diameter. Millimetres. Depth Millimetres. S. I I2J 5i 3" 133 18/9 BASINS AND CRUCIBLES FOR LABORATORY USE. Made of Pure Fused Opaque Silica. • '"-v; 2414 Finely glazed inside and outside. For most purposes they are an absolutely effective substitute for platinum. Constant in weight. They do not condense moisture on their surface when cooling. They are very durable, and superior to the best porcelain. The prices are low and comparable with those of porcelain. 2414T Silica Basins, opaque. INSIDE MEASUREMENTS. No. Diameter. Depth. Diameter. Depth. Price Each. Inches. Inches. Millimetres. M illimetres. B. i 2 « 51 21 21- B. 3 2| i 70 25 2/3 B. 5 31 Mr 83 30 2/6 B. 7 3i i 89 22 2/9 B. 9 31 IT"* 98 30 3/3 B. 10 4i if 108 45 3/9 470 BAIRD &.TATLOCK (LONDON) LTD. 415T Silica Basins, opaque, flat form. INSIDE MEASUREMENTS. No. Diameter. Depth. Diameter. Depth. Price Each. Inches. Inches. Millimetres. Millimetres. F. i 2i i 63 13 2/3 F. 2 2* i 73 13 2/6 F. 3 3f !,'; 95 18 2/9 F. 4 4£ -if 127 21 3/9 1161 Silica Crucibles, opaque, Berlin porcelain shape (glazed). OUTSIDE MEASUREMENTS. No. Height. Inches. Diameter at top. Inches. Height. Millimetres. Diameter at top. Millimetres. Price Each. C. oo t i If 2O 40 1/3 C. o I If 25 41 1/3 C. i I* If 28 47 1/6 C. 2 I* 2i 37 57 1/9 C. 3 If 2* 45 67 2/6 117T Silica Crucible Lids, opaque (glazed). INSIDE MEASUREMENTS. No. Diameter. Inches. Depth in Centre. Inches. Diameter. Millimetres. Depth in Centre. Millimetres. Price Each. L. o If 5 75 35 4 l/- L. i if 6 Ttf 45 7 i/- L. 2 2 A 5i 7 1/3 L. 03 21 5 IF 57 8 1/3 L. 3 2| t 60 9 1/6 L. 4 2| 1 70 13 1/9 418T Silica Crucibles, opaque, platinum shape. OUTSIDE MEASUREMENTS. Extra No. Height. Inches. Diameter at top. Inches. Height. Millimetres. Diameter at top. Millimetres. Each. Price for Lids. C. 4 2 2 50 50 2/6 1/3 C. 5 If If 35 35 2/6 I/- C. 6 II 4* 1 38 43 2/6 I/- CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. ~F= 471 BAIRD &. TATLOCK (LONDON) LTD. 2419T Silica Plates, opaque, up to 12 in. square, J in. thick, f d. per square inch. „ „ „ „ 12 by 6 in. square, £ in. thick, l^d. per square inch. 2420T Silica Plates, opaque, glazed up to 4 in. square by £ in. thick, 2d. per square inch. 242 1T Silica Rectangular Capsules, opaque, glazed, all measurements are internal. Length. Width. Depth. Length. Width. Depth. Price No. Inches. Inches. Inches. Mm. Mm. Mm. Each. R. i i& •H , 56 24 10 21- R. 2 if I| I 48 38 15 21- R. 3 zl If f 63 35 9 2/6 2422T Silica Circular Plain Capsule, opaque, glazed, all measurements are internal. No. Diameter. Inches. Depth in Centre. Inches. Diameter. Mm. Depth in Centre. Mm. Price Each. A. 5 if * 35 13 1/3 A. i If i 45 13 1/3 A. 2 2 i 5i 13 1/9 A. 6 21 •^4 * 57 13 1/9 A. 3 2 1 £ 60 13 2/- A. 4 2f i 70 16 2/6 SPECIAL CAPSULE FOR SUGAR ANALYSIS. AA. I. 2 i 5i 25 2/6 2423T Silica Trays, opaque, four sided, outside measurements. Length. Width. Depth. Length. Width. Depth. Price No. Inches. Inches. Inches. Mm. Mm. Mm. Each. T. 3 9i 2| I 235 66 25 4/6 T. 5 14 4s I 355 117 25 7/- T. 7 I2| 6 I -| 324 152 35 7/- T. 9 151 91 Ij 397 240 38 8/6 T. ii i6| "i I* 425 286 38 11/6 T. 13 i6| I3l Ii 425 340 44 14/- T. 15 10 7 I 254 I78 22 6/6 T. 17 6| 3f H 156 95 24 4/- 472 BAIRD &L TATLOCK (LONDON) LTD. 2424T Crucibles, Silica, opaque. No. Height. Inches. Diameter at Top. Inches. Height. Mm. Diameter at Top. Mm. Price Each. I 0 8 STS 2f 80 73 4/- 3 41 3f III 95 4/3 4 4 4i IO2 108 4/3 6 6J 41 155 "5 6/3 7 71 415 I9O 125 7/6 14 7* 5& I97 150 8/- 16 8! 6.1 213 159 10/- 30 iol 7* 260 197 15/- 60 I2| IOJ 324 257 20/- 62 I2| 12 318 305 25j- 70 20 12 508 305 35/- 2425T Silica Pipes, opaque, straight or socket. Bore. Max. Length. Bore. Max. Length. Price Inches. Inches. Mm. Mm. per Foot. 2 48 50 1,220 51- 3 48 75 I,22O 6/- 4 48 IOO 1,220 7/- 5 36 125 9-5 8/- 2426T Silica Muffles, opaque. 2426 No. Length. Inches. Width. Inches. Height. Inches. Length. Mm. Width. Mm. Height. Mm. Price Each. * 2 4* 2| 2f 114 67 60 3/9 * 4 6J 4l 3i 165 III 89 5/- * 6 9f 5i 5 241 149 127 8/3 * 8 15 9i 6J 381 235 156 13/9 *IO 15 ii 7 381 279 I78 18/9 *I2 i5l 13 7i 394 330 180 23/3 t65 9| 6| 4 235 168 IO2 8/3 f67 7! 5l 3i 198 144 82 71' f6g 7 3t 2| 178 86 73 51- *73 8 5 3f 203 127 86 61- i Sizes marked * are as No. 6. Sizes marked f are as No. 65. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 473 BAIRD &TATLOCK (LONDON) LTD. 2427 2428 2429 2427 Desiccators, glass dish, with cap ground to fit, and fitted with wire triangles. Diameter at mouth . . . . . . . . . . . . 3 Price .. .. .. .. .. .. .. 3/- 2428 Desiccators, without triangle .. .. .. .. .. 1/9 2429 Desiccators, Scheibler's, with glass cover and perforated zinc disc. Diameter . . . . 4 4f 6 9 Price .. .. .. .. 2/- 2/3 3/- 8/6 4 m. 4/- each, 2/9 „ 12 m. 18/- each. PP- 2430 2431 A2431 2432 2433 2430 Desiccators, Scheibler's, for Vacuum, with glass cover with tubulure in centre, ground to fit. Diameter inside . . . . . . . . . . 6 8 gf in. Price . . . . . . . . . . . . 4/9 7/6 12/- each. 2431 Desiccators, Scheibler's, for Vacuum, with glass cover ground to fit, with tubulure in centre, stopcock with hook, and I.R. Cork. Diameter . . . . . . . . . . . . 6 8 gf in. Price ... 6/9 10/- 15/- each. A2431 Desiccators, Scheibler's Vacuum, with stopcock ground in tubulure at side and cover ground to fit. Diameter . . . . . . . . . . . . 6 7 8 in. Price .. .. .. .. .. .. 7/- 9/- 1 1/- each. 2432 Desiccators, Fresenius' Vacuum, with glass stopcock and hook. Diameter at mouth inside Price zl 3* 4f in- 6/- 7/- 8/6 each. 2433 Desiccator, Reinhardt's, with rim turned upwards to prevent ground on lid from slipping off. Size of drying space, 6 by 6 in. . . . . . . . . . . . . £086 • CROSS STREET • HATTOIST GARDETST, E-C BAIRD &.TATLOCK (LONDON) LTD. 2434 2435 2437 2438 2434 Desiccator, new form, diam. inside mouth 4! in., the upper part is provided with stopper and a ground surface for writing on .. .. .. each, 3/3 ; per doz. £1 16 2435 Desiccator, Vacuum, of strong white glass, 6 in. diameter, stopcock with* hook, and I.R. cork £0 9 2436 Desiccator, Vacuum, of strong white glass, 6 in. diameter (Fig. 2435), without stopcock £0 7 2437 Desiccators, porcelain acid dish, perforated porcelain disc, ground glass plate, and bell jar. Diameter of bell jar . . . . . . . . . . 6 7 9 in. „ of porcelain dish for above . . . . 4| 6} 8 ,, Price complete as figured . . . . . . . . 6/6 8/6 13/3 each. 2438 Glass Plates, for above, ground on one side. Diameter 8 by 8 by £ 9 by 9 by -fg 10 by 10 by -|- n by n by f Price 1/3 1/7 1/10 2/- 0 6 0 12 by 12 by f in. 2/3 each. 2439 2440 2439 Porcelain Acid Dishes, for Desiccators, No. 2437. Diameter Price 2441 4l 2/3 2440 Porcelain Plates, with holes, for crucibles, for top of No. 2439. Diameter Price 5-1 2/9 4 1/3 2442 6J 3/3 5t 1/9 8 in. 5/6 each. 52 in. 2/3 each. 2441 Desiccators, Hempel's, with upper dish stoppered. Sulphuric acid or other drying agent is placed in the upper dish. Diameter inside of lower part . . . . . . 4 5 6 in. Price . . . . . . . . . . 4/- . 5/- 6/- each. 2442 Desiccators, Hempel's Vacuum, with upper dish fitted with stopcock. Diameter inside of lower part . . . . . . 4 5 6 in. Price . . . . . . . . . . 7/6 8/6 10/- each. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 475 BAIRD & TATLOCK (LONDON) LTD. 2445 2443 2444 2446 2447 2443 Desiccators, Hempel's, with separate dish, iron tripod, and cover with knob. Diameter . . . . . . . . . . 4 5 6 in. Price .. .. .. 4/6 5/- 6/6 each. 2444 Desiccators, Hempel's Vacuum, with separate dish, iron tripod, and cover with stopcock. 4 7/6 Diameter Price 5 9/6 6 in. 10/6 each. 2445 Diffusion Tube, 24 in. long, with porous septum each £0 0 2446 Diffusion Bulb, of porous clay. This is the simplest and most convenient form yet intro- duced .. .. .. .. .. each £0 1 2447 Digesters, iron enamelled inside, with handle. Capacity . . . . . . . . . . I it 2 gallons. Price 7/- 9/~- 11/6 each. 2450 2448 I;, i 1 2451 each 2449 2448T Diamonds, glaziers' 2449T Diamonds for writing on glass, best quality 2450 Pencils, for writing on glass, porcelain, etc. (red, yellow, blue, or green) each, 3d. ; perdoz. 2451 Dermatograph Pencils, for writing on glass, etc. Blue Leads Red per box of 6 £0 15 £0 4 £0 2 £0 0 £0 1 £0 1 CROSS STREET • HATTON GARDETST E-C BAIRD &TATLOCK. (LONDON) LTD. Drying Ovens. 2452-2453 Drying Stoves, for hot air, with stout cast bronze jacket and glazed porcelain inner chamber, with two porcelain shelves, and tube burners as illustrated. 2452s Height, iiiin. Breadth, qj -in. Back to front inside, gf in. .. .. .. £12 5 0 2453* i5| in. i2i in. n| in. £16 10 0 2454 2454s Drying Oven, of hard copper, hot air, three compartments, each 9 in. high, 7 in. broad, by 6^ in. deep, with shelf and two sets runners in each, with extra plate riveted to bottom and lower chamber of sheet iron . . £2 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. 2455 2456 5 6 7 8 9 10 10 in. 5 6 7 8 9 10 12 „ 5 6 7 8 9 10 10 „ 17/6 19/- 22/- ' 27/- 29/6 34/- 40/- 2455s Drying Ovens, hot air, single jacketed, of stout hard copper, with extra plate riveted to bottom, one sliding shelf on runners in centre, air regulator fitted on door. Height inside Width „ Depth Price with stand 2456s Air Bath, Dr. Lothar Meyer's, with double walled fireclay cylinder, inner bath of Russia iron with two walled cover to fit. Between the walls of the fireclay jacket a sheet iron cylinder is fixed in the centre. The heated air from the ring bunsen burner circulates between the walls of the fireclay and iron jacket to bath as shown in sketch, thus ensuring a uniform heating of the bath. A. Air bath, as above, with two cylinders of copper, with stand B. , sheet iron, with stand £1 17 £1 10 14- • CROSS STREET • HATTCflST GARDETST, E-C 47S BAIRD &.TATLOCK (LONDON) LTD. 2457-2458 2459 2457^ Drying Ovens, of sheet iron with double air jacket and ventilator at top. For drying at high temperature by means of hot air. Height of oven inside . . . . n Depth inside . . . . . . 7 Width inside . . . . . . 9 Prices, with stand . . . . . . £112 Price, covered with asbestos, extra . . £0 1 1 2458s Drying Ovens, as above, but made in copper throughout. Height inside . . . . . . n Depth inside . . . . . . 7 Width inside . . . . . . 9 Price with stand . . . . . . £27 Price covered with asbestos, extra . . £011 v 2459s Drying Ovens, copper, covered with asbestos, on stand (single jacketed), with 2 shelves. A. 12 by 8 by 8 in. inside B. 12 by 12 by 8 in. inside . . 12 14 in. 10 12 „ IO 12 „ 0 £2 2 0 £2 10 0 6 £0 15 0 £0 16 0 dou t. 12 14 in. 10 12 „ IO 12 „ 0 £3 9 0 £4 14 0 6 £0 15 0 £0 16 0 £2 10 £3 3 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 479 BAIRD &TATLOCKL (LONDON) LTD. 2460-2461 2462 Drying Oven, double walls, asbestos covered, 14 by 14 by 16 in. high, with perforated false bottom and movable shelf in centre, mounted on iron screen with set of three rose burners, complete. 2460s Price in copper . . 2461s Price in mild steel 2462s Drying Ovens of stout copper, all joints brazed for drying at high temperatures, on iron stand. The jacket may be filled with oil, glycerine, etc., according to temperature required. For drying ovens in constant use these are much more durable and will not leak. Inside sizes of oven :— Height .... 6 10 in. Width .. 6 I2 .. Depth (back to front) .... 6 10 „ price .. . . £2 18 0 £450 £5 10 £7 15 0 £650 0 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &. TATLOCK: (LONDON) LTD. 2463 2464 2463s Drying Ovens, hot water, double jacketed, of hard copper, one sliding shelf on runners in centre, with gauge. Height, inside measurement 567 Width „ 567 Depth (back to front) 567 Price with stand . . 22/- 26/- 35/- 42/- 9 10 10 12 in. 9 10 12 14 » 9 10 10 10 ,, 50/- 65/- 70/- 86/- each. Any other size made to order. 2464s Drying Ovens, double jacketed, of hard rolled copper, arranged for heating by electricity, each oven fitted with one movable shelf to centre. The heating elements are wound between two flat mica plates, which are inserted into a pocket in the water jacket of oven. The mica plates with heating resistance can be easily removed and fresh plates with resistance can be inserted without any trouble or alteration to bath. Arranged for any voltage, alternating or continuous, up to 200 volts. Inside sizes of oven : — Height Width Depth (back to front) Price, on stand, with wall plug and con- necting wire 6 6 6 7 7 7 8 10 in. 10 ,, 10 , £2 18 0 £3 10 0 £4 5 0 £5 10 0 SMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 481 BAIRD &TATLOCK (LONDON) LTD. 2465 2465s Drying Oven, hot water, of hard rolled copper, double jacketed, one sliding shelf on runners in centre, fitted with steam coil, with unions left ready for connecting to supply, with iron bracket. Inside sizes of oven : — Height Width Depth (back to front) Price Height Width Depth (back to front) Price 6 6 6 7 7 7 8 8 8 9 in. 9 .. 9 » £1 19 6 £2 8 0 £2 14 0 £336 10 10 12 in. 10 12 14 91 10 10 10 II .. £3 18 0 £5 0 0 £65 0 CROSS STRET • HATTOTST GARDETST, E-C- BAIRD &TATLOCK (LONDON) LTD. 2466 !4665 Drying Hot Water Oven, of bright hard rolled copper ; inside measurements, 14 in. high by 12 in. wide, by 10 in. back to front, with two perforated shelves on runners, top of oven provided with five holes for evaporating dishes, etc., each fitted with lid. Size of holes, 5, 4^, 4, 3, and 2\ in. diameter. Price, on stout iron stand . . !4673 Copper Hot Water Drying Oven, with Soxhlet's condenser and brazed copper flasks from 500 c.c. capacity, connected by unions, and bath fixed to iron plate for hanging on wall, with bunsen burner with stopcock. Oven, size inside . . . . 6 by 6 by 6 8 by 8 by 8 12 by 10 by 10 in. Price £330 £440 £5 10 0 £4 12 6 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 433 ; i BAIRD &TATLOCK (LONDON) LTD. 2468= Drying Oven for hot water, of bright hard rolled copper, with three chambers 8 by 8 by 8 in. inside. The central one is fitted with a sloping glazed door hinged at top ; on top of oven are five holes for evaporating dishes, etc. Size of holes, ij, 2, 3, 4, and 5 in., four fitted with covers, and the 5-in. hole with a set of copper rings, constant level arrange- ment fitted at side of oven, on stout iron stand 8 in. high £7 15 C 2469-2471 2472 Professor Reynolds' Improved Copper Water Drying Oven, with glass door on each side, constant level apparatus at end, three circular openings on top, 2 in., 2,\ in., and 3 in. diameter, with covers. Sides of bath fitted with water jacket to ensure uniformity of temperature. 2469s Price with stand, 10 by 14 by 12 in., 3 holes and covers . . . . . . . . £3101 2470s „ „ i2 „ 16 „ 14 „ 3 , „ ..£451 2471s „ „ 16 „ 18 „ 14 „ 4 „ „ .. .. . . . . £5 15 I 2472s Drying Oven, of hard rolled copper, for hot water. Inside size : height 9 in., depth (front to back) 8 in., width n.V in. ; gauge glass, stopcock, and double door with tube. The double door is for chloride of calcium, through which the air passes before entering the chamber. With stand . . . . . . . . . . . . £310' CROSS STREET • HATTON GARDEN, E-C BAIRD &TATLOCK (LONDON) LTD. 2473-2474 73s Drying Oven, with three chambers and gun-metal frame to doors, each chamber fitted with one movable shelf inside, on iron stand. Inside sizes of chambers :- Height Width Depth (back to front) Price £7 10 0 8 10 10 £8 17 10 in. 12 „ 10 „ £10 5 0 74s Drying Oven, as above, with three chambers, of stout copper, all joints brazed, for drying if required at temperatures higher than that of boiling water, by the use of oil, glycerine, etc., according to temperature required. These ovens are much more durable than the ordinary pattern with soldered joints, and for constant use as ordinary drying ovens will be found more economical, as there is no possibility of the joints leaking. The ovens are fitted with stout gun-metal framed*doors to each chamber, also movable shelf fitted in centre of each chamber (see Fig. 2473). Inside sizes of chambers : — Height Width Depth (back to front) Price 8 8 10 10 £11 10 0 £13 10 0 10 in. 12 „ 10 ,. £15 5 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 485 BAIRD &.TMLOCK (LONDON) LTD. 2475s Drying Oven, of bright hard rolled copper, with perforated, shelf in centre, pure tin worm condenser at side, in copper bucket and constant level arrangement from condenser to bath, on. stands. Inside sizes of oven : — . Height Width Depth (back to front) £600 £6 18 0 2476s Drying Oven, as above, with condenser at side and stands, oven covered with asbestos. Inside sizes of oven : — Height Width Depth (back to front) Price 486 BAIRD &TATLOCK (LONDON) LTD. 477; Steam Drying Copper Oven, with upper water bath on iron stand. The lower part consists of four ovens each 10 by 8 by 8 in., with brass doors and glass plate in each, one perforated shelf adjustable in two positions in each oven. The upper part is fitted with two sets of rings and lid of 8| in., two sets of 6 in., and one set of 4 in. diameter. Stop- cock to regulate steam on left hand, and tap to draw off condensed water in front. Total measurement outside, 39^ in. long, Q£ in. deep, 19 in. high without stand, 30 in. high with stand £15 0 0 2478 478s Drying Oven of hard rolled copper with three chambers having one shelf in centre, fitted on top with sets of iron rings for evaporating basins, etc., with iron screen and three bunsen burners with rose tops. Inside size of chamber : — Height ......' 6 7 9 in. Width ...... 6 7 9 „ Depth (back to front) . . 6 7 9 .. prke £5 17 6 £6 7 6 £750 £7 17 6 487 BAIRD &T&TLOCK. (LONDON) LTD. 000 2479 2479s Drying Oven, of hard rolled copper, with two compartments, each fitted with shelf in centre, and mounted on sheet-iron screen with rose top bunsens, pure tin worm condenser in copper bucket connected to oven by coupling screw, with constant level arrangement from condenser to oven. Inside sizes of chamber : — Height Width Depth (back to front) Price 6 6 6 £5 17 6 7 7 7 £676 8 in. 8 „ 8 „ £750 14- • CROSS STREET • HATTON GARDETST, E-C 48R BAIRD .ScTATLOCK CONDON) LTD. 2480 2480s Drying Oven of hard rolled copper, with two chambers at top and one large chamber at bottom, fitted with pure tin worm condenser in copper bucket, with constant level arrange- ment from condenser to oven, and one movable shelf to centre of each chamber, mounted on sheet-iron screen with rose top bunsens. Size No. i, with two chambers 6 by 6 by 7 in., and one chamber isi by 6 by 7 in. back to front £750 Size No. 2, with two chambers 7 by 7 by 8 in., and one chamber 15^ by 8 by 8 in. back to front £815 0 Size No. 3, with two chambers 8 by 8 by 9 in., and one chamber ij± by 9 by 9 in. back to front £9 15 0 489 BAIRD &.TXTLOCK (LONDON) LTD. 2481-2484 2481s Drying Oven, set of six ovens, 8 by 8 in., in two rows, of hard rolled copper, with glass doors hinged and fitted with gun-metal frames, brazed copper generator connected to oven by gun-metal unions and constant level arrangement, shelf in- centre of each com- partment. Price, with three rose top bunsens on stout iron screen as illustrated 2482s Drying Oven, set of six as above, but fitted with pure tin worm condenser in copper bucket alongside oven with steam pipe from oven to condenser and connecting pipe with coupling from overflow of condenser to constant level, on stand. For arrangement see No. 2480. 2483s Drying Ovens, set of six ovens, 6 by 6 in., in two rows, of hard rolled copper, with glass doors fitted in gun-metal frames, brazed copper steam generator connected to oven by gun-metal unions and constant level arrangement, one shelf to each compartment. Price, with three rose top bunsens on stout iron screen as illustrated 2484s Drying Oven, set of six as above, with pure tin worm condenser in copper bucket, on stand (see Fig. 2480) . . £17 10 0 £19 5 0 £15 15 0 £17 17 0 CROSS STREET • HATTOTST GARDEN, E- C 490 BAIR-D &.TXTLOCK (LONDON) LTD. 2485 !485S Drying Ovens, as Nos. 2481 and 2483, without steam generator or burners, but fitted with steam coil inside and unions at end of coil for connecting to supply and exit pipe, with iron brackets for fixing to wall. Set of 6 ovens . . . . . . . . 6 by 6 8 by 8 Price .. .. .. .. .. £14 14 0 £16 16 0 This pattern of Drying Oven can be supplied with any size and number of Chambers required. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 491 BAIR.D &TATLOCK (LONDON) LTD. 2486s Drying Oven, for hot water, of hard rolled copper, consisting of six chambers 6 by 6 by 7 in. inside, with one shelf in centre to each, and two chambers each 9 by 9 by 8 in. inside, with two shelves to each. A heavy brazed copper steam generator is connected to the bottom by means of brass coupling screws, so that it can easily be removed if required. A constant level in same is maintained by means of a connection from top of condenser. The bath is mounted on heavy sheet-iron stand with brackets for fastening to wall, the pure tin worm is contained in a copper condensing bucket. Price, complete with set of rose bunsen burners, as illustrated £22 10 0 2487s Drying Oven exactly as above, but doors of glass in gun-metal frames (see Fig. 2481) . . £27 0 ' This Pattern of Drying Oven can be supplied with any size and number of Chambers required. CROSS STREET • HATTOTST GARDEN, E-C 492 BAIRD &.TATLOCK (LONDON) LTD. 2488' 2488 2489 Electric Oven, 14 by 14 by 12 in. high (inside), 220 volts, about 6 amperes, complete with thermometer and regulating resistance These Ovens are made for voltages from 100 to 400, for temperatures up to 250 centigrade, and are fitted with a regulating resistance for regulating the temperature from 15 degrees upwards The floor consists of a wrought-iron plate easily removable, admitting of access to the heating system, which together with the material used for insulation combines to form a cleanly and most efficient apparatus, possessing many advantages over similar apparatus heated by gas. Quotations for any size on receipt of particulars. Please state voltage required. 2489T Drying Chamber or Desiccator of glass, in stout nickel-plated brass frame, with perforated metal stand, glass shelves and dish for the drying agent, with two compart- ments 12 by 10 by 10 in., fitted with doors £15 10 0 £650 A2490 A2490T Drying Chamber or Desiccator of glass, in stout nickel-plated brass frame, with perforated metal stand, glass shelf and dish for the drying agent, with one compartment 12 by 10 by 10 in., fitted with door £3 17 6 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 493 BAIRD &TATLOCK (LONDON) LTD. .ST. 2491) 2491 2490s Drying Oven, copper, for brewers' chemists, with chamber, 7 by 6 by 6 in., two holes in top for 2f -in. funnels, one for 4i-in. basin, and two for 3-in. basins, with lids. Price with stand . . . . . . ' . . . . ..£27 2491s Water Bath, copper, for brewers' chemists, with water jacketed chamber, 10 by 4^ by 5 in., four hot water funnels in top for filtering. Price with stand . . . . . . £215 2492 2493 2492s Water Bath, copper for mashing, as used by brewers' chemists, with four holes, 4j in. diameter, for No. 7 glass beakers, with perforated false bottom, and stand . . each £1 15 0 2493s Mashing Bath, copper, 8 by 8 by 4 in., with perforated false bottom and four spun copper beakers, 4 by 2\ in., with lids, on stand . . . . . . . . . . . . £1150 CROSS STREET • HATTON GARDEN, E-C 494 BAIRD &.TATLOCK (LONDON) LTD. 2494 2495 2494s Mashing Bath, of copper, 12 in. diameter, with six copper beakers, 5 by 3 in., and lids, fitted with false bottom on which the beakers rest, and stirring arrangement so that the beakers can be maintained at an even temperature . . . . . . . . £2176 2495s Copper Capsules, for testing malt, 2! in. diameter . . each, 1/1 ; per doz. £0 12 6 2496 2497 2496s Evaporating Bath, copper, 16 by 12 by 3! in. deep, with 12 holes fitted with sets of copper rings, diameter of each hole 3 in., on stand 2497s Evaporating Bath, copper, as above, 12 by 9 by 3^ in. deep, with 6 holes, 3 in. diameter, each hole fitted with set of copper rings 2498s Evaporating Bath, copper, as above, with holes 3 in. diam., fitted with sets of copper rings, fitted with steam coil inside for heating (see Fig. 2465), with union left for connecting to main supply, and exit pipes. Bath with . . . . . . . . . . 12 holes 6 holes Price .. .. .. £300 £220 Constant level fitted if required, extra . . . . £050 £050 £276 £196 495 ear* BAIRD &TATLOCK (LONDON) LTD. 2499 2500 2499^ Evaporating Bath, copper, 24 by 8 by 5 in., fitted with 3 sets of porcelain rings, 6J in. diameter, 7 rings in set. Price on stand 2500s Constant Temperature Drying Oven, designed by R. L. Siau, Esq., made in hard rolled copper with gun-metal door and swing screws to fasten. Size of inside chamber 18 by 3 by ii in., with wire gauze tray ior carrying the drying capsule fitting the entire length of chamber. Brazed copper flask connected by screw coupling and nickel-plated ball condenser at top. Complete with stand. Price The oven may be heated by water, toluol, or other liquid of fixed boiling point, and the heating spiral, which is coiled between inner and outer jacket, is connected to a water filter pump. A constant stream of heated air is thus drawn through the inner chamber. The temperature can be varied according to the liquid used through which the heating coil passes. For further description see Journal of Society of Chemical Industry, vol. xxx., page 61. £256 £4 10 2501 2501s Copper Water Bath, size 19 by 6J- by 4 in., with three openings fitted with nickel iris- diaphragm, 4 in. diameter, closing to | in., on stand The above is specially adapted for use with Fat Extraction Apparatus. £4 10 0 CROSS STREET • HATTO^T GARDEN, E-C- 496 BAIRD &TATLOCK. (LONDON) LTD. 2502 2502s Drying Oven, of bright hard rolled copper, after Soxhlet, for the rapid drying of residues in milk. Size, 21 by 6J by 6J in., with eight brass tubes and drying chamber length- ways, wire gauze tray for flat metal basins, to fit into chamber, Soxhlet 's condenser and draught; arrangement fitted on top of oven. Price, complete with five flat metal dishes, one cover and nickel shovel, as illustrated £7 10 0 '" ' H^»^"~" 2503 2504 2503s Copper Water Bath, 13 by gi by 5 in., on stand, with i set of 4^ in. copper rings and 2 holes with covers, 3 in., water funnel for filtering, and small drying chamber with door -\2503S Copper Water Bath, as above, fitted with constant level to bath 2504s Copper Forcing Trays, with tube at corner for filling, and brass tap for emptying, on stand, for brewers' use. A. B. C. D. 24 x 16 x 4 18 x 12 x 3 15 x ii x 3 12 x 10 x 3 in. £2 10 0 £250 £200 £1 12 0 £1 15 £1 18 497 BAIRD &TATLOCK (LONDON) LTD. 2505 2506 2505s Copper Water Bath, 10 by 8 by 4^ in., for milk analyses, etc., with six holes and nickel capsules, y.\ in. diam. Price with stand . . . . . . . . . . £130 25069 Nickel Capsules, z\ in. diam., for No. 2505 each, 1/3; per doz. £0 14 0 2507 2507A Copper Water Baths, spun in one piece, with handles and copper rings, edges of rings as shown in Fig. 2 2507s 2508s Diameter No. of rings Price Iron stands for above, extra 5 4 l/- 6 5 1/3 7 6 1/9 8 7 9/6 9 n. 13/- 2509s Copper Water Baths, spun in one piece, with copper rings, and constant level, on stand. Diameter No. of rings Price 7 6 14/- 9 in. 8 19/6 2510s Sets of Copper Rings, for water bath?, evaporating baths, etc. No. of rings . . . . 4 5 6 7 8 Diameter of largest ring . . 4^ 5 5f 6| 7f Price .. .. .. 2/6 3/- 4/6 4/9 6/- 9 8j 7/- 10 9a in. 8/- per set. The above baths are fitted with rings in which the sharp edge is turned down, thus lessening the risk of fracturing flasks or beakers, as shown in Fig. 2507A. CROSS STREET • HATTOlsr GARDEN, E-C 498 BAIRD &TATLOCK (LONDON) LTD. 2511 2513 2514 Copper Water Baths, cylindrical form, fitted with handles and Sets of copper rings, for use with electrical hot plates, etc., or with stands for use with gas burners. Diameter . . . . . . . . ' 6 8 10 in. Depth ..5 6 7 „ 2511s Price without stand .. .. .. 9/6 15/- 23/- 2512s Price with stand .. .. .. 10/9 17/- 25/6 (See Nos. 2530-2534 for electrical hot plates suitable for above.) Water Baths, light enamelled iron, white inside, blue outside, with handles, with or without copper rings. Diameter . . . . . . 6i Height .. .. .. 5 2513s Price without rings but with stand 2/6 , 2514s Price with copper rings and stand 7/6 2515 2517 2515s Copper Water Bath, with set of 7 porcelain rings, diameter of bath 7^ in., on stand, with constant level . . . . . . . . . . £0 17 2516s Copper Water Bath, as above, without constant level, on stand . . . . . . £013 2517s Copper Water Baths, funnel shaped, with constant level and set of 7 copper rings, on stand. 7 9 Diameter Price 13/6 in. 16/- each. jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 499 2 K BAIRD &IATLOCK (LONDON) LTD. 2519 2522 2518s Copper Water Baths, funnel shaped, with constant level and porcelain rings, on stand. Diameter .. .. .. .. 7 9 in. Price .. .. .. •• •• •• 15/6 18/6 each. 2519s Water Bath, of copper, 9 in. diameter, with rings and constant level arrangement, with glass water reservoirs . . . . • • • • • • • • • • . . £1 2520s Water Bath, as above, 7 in. diameter, with rings and constant level arrangement, etc. . . £0 2522s Water Bath, of copper, 8 in. diameter, fitted with iris-diaphragm and constant level, on stand . . • • • • • • ..£17 2 0 19 6 2523-2525 Water Baths of Copper, tinned inside, adapted for heating by electricity, fitted with set of copper rings. 2523' 2524* 2525T -X" ,~^Sl£S Water Bath t> it ft t) ft Diam. 4i in. 5 „ 6 „ Max. Voltage. 250 250 250 Current Consumption. No. 300 500 60O ^^^sSSf^fr^ — r FfP^ of Circuits. I I I Price complete with Copper Rings. £1 15 0 £220 £2 11 0 rii/r£\^ 1 ifi«' •* IJf]] 14 • CROSS STREET • HATTOTST ^s.-^~ny^ —•*—* ^_ GARDETST, E- C^Jl 500 RAIRD &TATLOCK. (LONDON) LTD. 2530-2532 2529 2533-2534 2529T Water Bath of Copper, with constant level, and porcelain cover, fitted with 4 holes and lids for same. Diameter of cover . . . . . . 180 230 mm. Size of holes . . . . 36, 44, 50, and 53 mm. 43, 50, 55, and 60 mm. Price with stand . . . . . . 16/- 19/- Electric Hot Plates, of cast iron, ground and polished flat on their top surface and edges, and mounted on a cast iron enamelled base. Temperature of surface about 600° F. 2530T Electric Hot Plate, 6 in. diam. Maximum voltage, 250. Wired for 350 watts 2531T „ ,, 8J „ „ „ 250. „ 600 „ 25321 „ ,, 12 „ „ „ 250 : 3 circuit, 4-8 or 1,200 25331 ,, ,, 16 by 10 in. ,, ,, 250:3 „ 4-8 or 1,700 2534T „ 18 by 12 „ „ „ 250 : 4 „ 3-S-I5 or 1,800 £1 £1 0 7 £2 10 £2 10 £3 12 0 0 0 0 0 2535 2536 2537 J5359 Water Bath, pure nickel, j\ in. diameter, with four rings. Price with iron stand . . £110 2536 Porcelain Rings for water baths, glazed on top, in sets, with centre cover. Sets of . . . . i to ii i to 7 i to 5 i to 4 i to 3 160 120 97 76 mm. diam. outside. 3/6 2/6 21- 1/9 per set. !537 Porcelain Covers for water baths (see Fig. 2529), with four holes and lids, for evaporating dishes, etc. Diameter . . . . . . 180 230 mm. Size of holes . . . . 36, 44, 50, and 53 mm. 43, 50, 55, and 60 mm. 3/6 5/6 each. Largest ring Price Price 230 7/6 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 501 BAIRD &TATLOCK (LONDON) LTD. 2538 2539 2538s Victor Meyer's Crucible Drying Bath, of heavy copper, brazed, with double walls, 10 by 10 centimetres inside, with porcelain plate, and burner on stand (See Ber. d. D. Chem. Ges., 1885, s. 2999.) £1 2539s Copper Water Bath, 6 in. diameter, with removable holder for 12 test tubes, holes numbered I to 12, and hole for thermometer, on stand 8 in. high . . . . . . £0 14 2540 A2540 2540 Sand Time Glasses, in wooden frame. B2540 A2540 3 5 15 30 I/- 1/6 2/- 2/3 Sand Baths, shallow tinned iron. Diameter .. 4i 5i 6J 7^ 8J 60 minutes. 2/6 each. 8J 9l loj in. Price .. Id. l|d. 2d. 2|d. 3d. 3|d 4d. 5d. each. lid. 1/4 1/9 2/3 2/9 3/3 3/9 4/9 per doz B2540 ^oCTis *-~s2o?tw Sand Baths or Basins, tinned iron, seamless, diameter 6 in. each, 4d. ; per doz. £0 3 fas^. CROSS STRET • HATTCTST GARDE1ST, E- C 502 BAIRD &TATLOCK (LONDON) LTD. 2541 2542 2541 Fletcher's Laboratory Burners and Sand Baths. No. Support for flasks, diameter Support for flat vessels, diameter Sand bath Price complete 2542 Sand Bath, for laboratory use, with cover for evaporating corrosive liquids. Size of bath, 12 in. square inside. Fitted with burners with tap to each for controlling the tempera- ture in any part. The back is open, to fit against a wall with a flue . . . . £2 10 4t 6J 9 5/2 15 51 7* 10 6/6 20 7 9 13 9/3 30 8 in ii „ 15 ., 20/- 5 0 2543 2544 2546-2547 2543 Flask or Basin Guards, sheet iron, with asbestos protecting strips fastened inside. ii 13 15 18 22 27 cm. 1/3 1/6 2/- 2/3 2/3 2/6 each. 2544 Asbestos Air Baths, round, suitable for flasks of 8 to 100 oz. Price for set of four 2545 Tripod adapted for all sizes . . . . . . . . . . . . each £0 10 0 £026 25461 Dr. A. Classens' Apparatus, for the electrolytic estimation of copper, consisting of platinum cone and spiral, price depending on market price of platinum . . . say £12 0 0 2547r Tripod stand, insulated, with brass rod and connectors for ditto .. .. each £056 (See also Platinum Electrodes, No. 2368-2383.) 503 BAIRD &TATLOCK (LOM)ON) LTD. 2548 2549 2550 2551 2552 2553 21 2548 Soxhlet's Fat Extraction Apparatus, of brass, nickel-plated . . • • . . £0 2549 Fat Extraction Apparatus, Soxhlet's, as used in Dr. Skalweit's laboratory. The ether or other volatile solvent is heated in a flask, rises through side tube to condenser, where it is condensed, and, falling on the sample, extracts the oil and returns by syphon again to the flask. 30 60 100 200 grammes to top of syphon. 2/2 2/3 3/- 4/6 each. 2550 Soxhlet's Fat Extraction Apparatus (as No. 2549), witn stopcock. 30 60 100 200 grammes to top of syphon. 3/9 4/- 4/9 7/-each. 2551 Soxhlet's Fat Extraction Apparatus, with condenser, and six flasks ground to fit. Capacity of Extractor 60 100 200 grammes to top ot syphon. „ Flask 90 125 250 Price complete 12/- 14/6 17/6 each set. 2552 Fat Extraction Apparatus, Soxhlet's pattern, with B. & T.'s double surface condenser and six flasks made of Resistance glass ground to fit. Capacity of Extractor 60 100 grammes to top of syphon. „ Flask 90 125 IS/- 18/-each. 2553 Extraction Apparatus, Soxhlet's, flask with mercury seal, and condenser ground to fit. Capacity of Extractor 60 100 200 grammes to top of syphon. Flask 90 125 250 Price 9/3 11/3 15/- each. 2554 Extraction Apparatus, Soxhlet's, fitted with new form condenser ground to fit, and 3 flasks ground to extractor. Capacity of Extractor 60 100 200 grammes to top of syphon „ Flask 90 125 250 „ Price 12/6 16/- 18/6 each. BAIRD &TATLOCK (LONDON) LTD. B 2555 A2555 2556 2555 Fat Extraction Apparatus, by Dr. E. Drechsel, with mercury seal. 2557 2/6 31- .\2555 Fat Extraction Apparatus (Greiner & Friedich's) . Capacity of filter tube . . 60 31- i litre. 4/- each. 100 •200 grammes. 5/6 each. 2556 Extraction Thimbles of Fat-Free Paper, C. S. & S., No. 603. These extraction cups of fat-free paper are for use with the Soxhlet extraction apparatus, Nos. 2548-2554. Seamless, and made from the best filter paper material, it is absolutely impossible for any particles of the substance undergoing extraction to find their way into the ether. The ether itself flows readily from the shells, and the extraction is greatly facilitated. Packed in boxes, containing twenty-five thimbles. Cups can be used repeatedly. Length . . . . . . 60 80 80 80 90 94 Diameter . . . . . . 26 22 30 33 19 33 Per box of 25 .. ..5/3 5/3 5/9 5/9 5/3 7/3 Suitable for . . . 30 60 100 123 millimetres. 43 11/3 200 gramme Extractors. 2557 Extraction Apparatus, new pattern, with three flasks, condenser and Soxhlet's extractor all ground to fit . . . . . . . . . . . . . . per set A New Apparatus for Extracting Liquids. — Hitherto all the usual types of apparatus for extraction of liquids have very fragile spirals, are difficult to clean and if a large quantity of liquid is to be extracted, the extraction must |be interrupted by changing the liquid. The apparatus avoids these disadvantages. This differs from the usual Soxhlet apparatus for extracting solids only by the inner funnel-tube with a spiral- jacket, the inlet funnel and the higher opening of the syphon. The use of the apparatus is as follows : The apparatus is filled with the liquid up to near the syphon. Then by heating the flask filled with ether, etc., <•(<•., the ether vaporizes and the vapour goes through the vapour-tube to the condenser as in the ordinary Soxhlet apparatus. The condensate drops in the inner funnel-tube and rises in small drops following the thread of the tunnel-jacket to the surface of the liquid. In this manner very good contact between the ether and the liquid to ^tracted is obtained. The ether accumulates above the surface of the liquid until it syphons over and the operation continues. Upon finishing the extraction, which can be ascertained by testing a small portion of the liquid drawn off through the cock, the liquid is removed and a new portion added through the funnel without taking the apparatus apart or interrupting the heating. The condenser is a new return-condenser with the principle of counter-currents. The essential feature of this condenser is the spiral cooling tube. The condensate between it and the outside jacket forms a seal, compelling the vapour to travel a spiral distance of 4 feet up through the condenser. To avoid heating the incoming cooling water by the outgoing warm water the outlet tube is insulated by an air-jacket. This jacket is enlarged so as to make the cooling water also take a spiral course exactly against the vapour. [Reprinted from The Jour/iM of the American Chemical Society. Vol. XXXIV. No. 3. March, 1912.] £1 12 6 J 505 BAIRD &1MXOCK (LONDON) LTD. A2557 2558 2559 A2557 Fat Extraction Apparatus, devised by Messrs. Clayton, Beadle & Stevens. This is a simple form of apparatus to dispense with the necessity for corks or ground joints. Another feature is its compactness. For full description see Analyst, page No. 143, April, 1913. Size of Soxhlet tube . . . . i\ in. by I in. 3 in. by ij in. Price . . . . . . . . 4/6 5/- each. 2558 Fat Extraction Apparatus for rapid and complete extraction with minimum loss of solvent, specially suitable for the routine analysis of cocoa, chocolate, feeding stuffs. The material is weighed directly into one of the inner tubes (three different sizes of which are supplied), and may be conveniently dried in the same tube after extraction. (See Bolton and Revis, " Fatty Foods," J. & A. Churchill, 1912.) 2559s Water Bath, of copper, with cover and three apertures covered by lids, for three sets Soxhlet's fat extraction apparatus, on tripod stand, with tripod stand and rod, three clamps, and circular gas burner. Price, complete with glass parts, as illustrated Prices of Separate Parts. 2560s Water Bath, with cover 2561s Tripod for bath 2562" Tripod Stand with rod 2563s Set of three clamps 2564s Gas Burner with three jets 2565s Set of 3, 60 gramme Soxhlet's Extractors, with stopcock (Fig. 2550), condensers, and flasks 2566s Set of 3, 60 gramme Soxhlet's Extractors (Fig. 2549), with condensers, and flasks £0 12 6 £426 9 6 4 6 £1 £0 £0 £0 13 0 £0 12 0 2 6 £140 £0 18 9 14- • CROSS STREET • HATTOTSr GARDE1ST, E- C 506 BAIRD &TATLOCK (LONDON) LTD. 2567 Water Bath, of stout copper, for fat extraction apparatus, on tripod, with gas burner, rod, and clamps, and six sets glass apparatus, corks, etc., complete for six extractions £5 7 Water Bath, same as above, but with spirit burner instead of gas burner . . . . £67 Prices of Separate Parts. Water Bath of stout copper, for six Soxhlet's fat extraction apparatus . . . . £1 16 Tripod of wrought iron . . . . . . . . . . . . ..£05 Stand, rod on tripod foot . . . . . . . . . . . . ..£03 Extraction Apparatus, 60 grms., flask 100 c.c. and condenser, complete, per set . . £06 Clamp, with six arms, for supporting the Soxhlet apparatus . . . . . . ..£018 Circular gas burner . . . . . . . . . . . . ..£015 Berzelius Argand spirit lamp, with three burners . . . . . . . . £110 6 6 6 6 6 6 0 0 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 507 BAIRD &TATLOCK (LOM)ON) LTD. 2577 2579 2576 Files, round, best Lancashire, for enlarging holes in corks 2577 Files, round, as above, with handles 2578 Files, triangular, best Lancashire cross cut, 34 in. 2579 Files, triangular, as above, with handles, 3* in. 2580 Files, flat, best Lancashire 2581 Files, flat, as above, with handles 6 7d. 6 9d. 7 9d. 7 lid. 2581 5 6 in. 5d. 6d. each. 4/9 5/9 per doz. 5 6 in. 7d. 8d. each. 6/3 7/3 per doz. each, 4d. ; per doz. £0 each, 6d. ; per doz. £0 8 10 in. lid. 1/3 each. 8 9 in. 1/1 1/5 each. 2582 Files, wooden handles for, with brass ferrules, to suit Nos. 2576 and 2578 each, 2d. ; per doz. £0 2586-2587 2584 2585 2588 2583 Filter Cases, japanned tin, to contain one packet of 100 circles. To hold filters .. ..7 9 n 12.5 Price .. .. 4d. 5d. 6d. 7d. to i8J centimetres 15 9d. 18.5 cm. diam. I/- each. 2584 Filter Case, of japanned tin, to hold six sizes, 2585 Filter Cutters, tin, 18 in set A2585 „ „ „ 3 in set 2586 Filter Discs, perforated porcelain, with bevelled edge for use in glass funnels. £0 7 '£0 3 £0 0 Diameter 25 40 45 SO 9° 170 mm. Price . . .. 4d. 5d. 6d. 6d. 1/2 1 /8 each. » .. 3/9 4/6 5/6 5/6 13/- 19/- per doz. 2587 Filter Discs, perforated glass. Diameter . . . . . . t . ij ij 2 in Price lid. I/- 1/3 each. 2588 ..<- •^y48 Polished Tool Cabinets of Oak (similar to Fig. 2595) , containing 2 hammers, hatchet, mallet, hand-saw, pincers, pliers, 2-ft. rule, square, spokeshave, plane, 2 gimlets, 2 bradawls, compasses, 2 turnscrews, tack-claw, cold chisel, brad punch, 2 files, rasp, 2 chisels, gouge, oil stone, oil can, glue pot and brush, nails, etc. . . . . . . . . . . £2150 2 >58 Polished Tool Cabinets of Oak, containing 2 hammers, mallet, hatchet, hand-saw, tenon saw, saw-pad and saw, hand vice, pincers, cutting pliers, 2-ft. rule, bevel, square, spokeshave, smoothing plane, 4 gimlets, 4 bradawls, compasses, 2 turnscrews, 2 files, rasp, 4 chisels, 2 gouges, 2 brad punches, striking knife, drawing knife, brace and bits, scraper, movable spanner, spirit level, oil stone, oil can, glue pot and brush, nails, etc. . . . . £600 Any item in above sets sold separately. BAIRD &TATLOCK (LONDON) LTD. 2596 2596 Chisels for cutting metal 2597 Screwdrivers . . 2598 Mallets, beech, morticed 2599 Scissors 2598 3 lOd. 46 1/6 2/3 5 1/6 2599 each £0 1 8 in. 3/4 each. 7 in. 3/- each. per pair, 5! in., I/- ; 6J in. £0 1 2600 2601 2603 2602 2600 Anvil, or " Square Stake," polished face, best steel, with tang — Weight . . . . . . . . ij 2 3 Ib Size of face about . . - . *-.•.!* i| 2 Price .. .. .. ..3/6 6/6 9/6 2601 Hammers, flat one end, pointed the other, handled — Head . . . . . . . . . . 3 4 in. long. Price .. .. ..1/92/3 each. 2602 Hammer . . . . . . . . . . No. i. No. 2. 1/6 ' 1/8 2603 Spanner or adjustable wrench, steel nickel-plated. Opens i in. i? in. 3| in. sq. 21 /- each. £0 £0 CROSS STREET • HATTCW GARDEN, E-C- 510 BAIRD &TATLOCK (LONDON) LTD. 2604-2607 Vice, Hand— 604 Length, 3 in. 605 „ 4 in. 606 „ 5 in. 607 „ 6 in. Vice to screw to table — 608 Weight, 2j Ibs. 609 „ 3ilbs. 5 Ibs. 610 2608-2610 Vice, Strong Parallel— 611 Jaws, 2\ in., open to 3 in., weight about 7 Ibs. . ; 612 „ 3i in. „ 4J in. , 20 Ibs. 2611-2613 each n- 5i in. 46 Ibs. £030 £040 £056 £090 £066 £086 £0 10 6 £0 10 6 £0 17 6 £1 15 0 2614 2615 2617 614 Filter Rings, porcelain, two arms 615 Filter Rings, porcelain, three arms 616 Filter Cones, platinum. See No. 2349. 617 Porous Porcelain Filter Cones, Royal Berlin Ware. Height .. .. .. .. 40 Diameter . . . . . . . . 52 Price .. .. .. .. 7d. 618 Porous Balloon Filters, Royal Berlin Ware. No. .. .. .. .. i Capacity . . . . . . . . 50 Price .. .. .. .. 1/4 2618 each £004 £006 57 72 lOd. 2 I4O 71 mm. 90 mm. 1/2 each. 3 1,000 C.C. 6/- each. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 511 BAIRD &. TATLOCK (LONDON) LTD. 2619-2620 26191 Chardin's Agar-Agar Filter Paper, 50 centimetres, folded, in boxes of twenty-five per box £0 3 ( 2620T Chardin's Agar-Agar Filter Paper, 32 centimetres diameter, in boxes of fifty folded niters . . . . . . . . . . . . . . . . per box £0 4 ( 2621T Chardin's Agar-Agar Filter Paper, in sheets. 50 cm. diam. circular. 50 by 50 cm. square. Per 100 sheets .. .. ..9/6 9/6 Per 1,000 sheets .. .. . . £4 10 0 £4 10 0 !••••••••••••••• • •• • • ___ immmmmmmmmmmmmmmmmmmm, :::::::::::::::::::::::;::::::::::::: ::::::::::::::::: 5 «••»••••«••••••••»••••••• •••••••••• ••••••••••••••••• ::::::::::::::::::::::;:: ::::::::•• ::::::::::::::::: 2622 2624 2622* 2623* 2624* 2625T 2626s £056 £0 12 0 Sectional Paper, specially ruled for accurate work. Ruled in millimetre squares with the centimetre and half-centimetre lines thickened. Size1 of sheet, 56 by 43 cm. Per sheet, 3d. ; per quire Tracing Sectional Paper, transparent, ruled in blue in mm. squares . . per quire Sectional Paper, ruled in tenth-inch squares with the inch and half-inch lines marked. Size of sheet, 17 by 22 in. . . per sheet, 3d. ; per quire £056 Tracing Sectional Paper, transparent, ruled in blue in mm. squares, 18 by 23 in. per quire £0120 Sectional Paper, in millimetre and centimetre squares, for mapping curves etc Size of sheets, 27 cm. by 21 cm. .. . . . . . . . . per' quire £006 CROSS STREET • HATTON GARDETST, E-C 512 BAIRD &.TATLOCK (LONDON) LTD. 2627-2629 2636-2638 627" Books. Laboratory Note with logarithms, rales, tables, formulae (papyrolin covers). 80 pages, 21 cm. by 13 cm., millimetre squares, interleaved . . . . each 328s Books. Laboratory Note as above, but with stiff covers. 80 pages, 21 cm. by 13 cm., millimetre squares and interleaved . . . . . . . . . . each 5299 Books. Cheap pattern, with paper covers. 48 pages, 21 cm. by 13 cm., millimetre squares and interleaved . . . . . . . . . . . . . . each S30S Laboratory Note Books. Cheap pattern, with paper covers, with logarithms, rules, tables, and formula?. 56 pages, 8J by 5^ in., ^ in. squares . . . . . . each J318 Sectional Paper for mapping curves. Size, lol by 8| in., ^ in. squares. per quire >323 Sectional Paper for mapping curves. Size, 58 cm. by 45 cm., 2 mm. squares, per quire )339 Sectional Paper for mapping curves, etc. Sheets 23 by 18 in., ruled lines every i and i in. . . . . . . in. squares, heavy . . per quire >348 Sectional Paper for mapping curves, etc. In sheets, 23 by 18 in., ^ in. squares, heavy ruled lines every i in. . . . . . , . . . . . . . per quire >35" Books. Laboratory Note with logarithms, rales, tables, formulae (papyrolin covers). 120 pages, 8£ by 5| in., ^ in. squares . . . . . . . . . . each !635S Books. Laboratory Note (as No. 2635), with stiff covers . . . . . . „ >36a Sectional Pads, containing 100 leaves, 8 by 5 in., ruled in ^ in. squares each, 9d. ; per doz. )379 Sectional Pads, containing 100 leaves, ioi by 8£ in., ruled in TV in. squares each, 1/6; per doz. >388 Sectional Pads, containing 100 leaves, 26 by 21 mm., ruled in millimetres each, 1/6; per doz. )39s Sectional Paper, in rolls, each 50 yds. long by 24 in. wide, ruled in green, showing i in., i in., and ^ in. . . . . . . . . . . . . . . per roll £004 £006 £002 £0 0 2 £006 £013 £013 £013 £004 £006 £086 £0 17 6 £0 17 6 £176 I '^Q^ CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 513 BAIRD &TATLOCK: (LONDON) LTD. 2640 2640T Filter Paper, French grey, in packets of 100 circles. 15 i8i 25 33 6 7£ 9i !3 8d. lOd. I/- 1/6 6/6 8/- 9/6 14/6 39 15* 2/- 19/- 45 50 cm. 17! igi in. 2/3 2/6 packet of 100. 21 /- 23/6 per 1,000 filter.' 2641 2641T Muencktell's Best Swedish Filter Paper, No. 1 F. 5i 7 9 ii i4 2* 2| 31 41 4| 15 51 7i 24 centimetres. i in. Weight of ash per filter .00014 .00023 .00038 .00056 .00073 .00105 .00161 grammes. Price .. 5d. 6d. 9d. I/- 1/3 1/6 2/4 3/8 packet of 3/6 4/6 7j- 8/9 11/9 14/6 21/- 35/- per 1,000. - 2642T Muencktell's Swedish Filter Paper, No. 2. 5-5 79H I2i 15 i8| cm. Weight of ash per filter 0.00018 0.00030 0.00051 0.00074 0.00095 0.00138 0.00209 grammes. Price .. .. 4d. 5d. 8d. lOd. I/- ~ 1/4 1/9 per 100. .. 3/- 3/9 6/- 7/3 9/3 12/- 15/9 per 1,000. 2643T Muencktell's Best Swedish Filter Paper, treated with hydrochloric acid, No. 0. 5i 79JI I2J 15 cm. 2i 2f 3£ 4j 5 sJ in. Weight of ash per filter 0.000060 o.oooio 0.00017 0.00025 0.00033 0.00046 grammes. Price .. .. 9d. lid. 1/5 1/10 2/2 2/9 per packet of io< 6/- 8/3 12/6 16/- 19/- 24/9 per 1,000. 26441 Filter Paper in sheets, Muencktell's Swedish. No. 1 F., thin unwashed. per quire, 3/- ; per ream A2644' i;2644T No. 2, ordinary thickness per quire, 2/9 ; No. 0, specially washed with HC1 per quire, 6/3 ; £2 16 £25 „„ CROSS STRET • HATTCHSr GARDETST, E-C 514 BAIRD &TATLOCK (LOM)ON) LTD. FINEST ENGLISH BAIRD &TATLOCK (LONDON) LT a ST. HATTON GARDEN 2645 645 Superior White English Cut Filters, " Quick Filters." 2j 2f 3J 4i 5i 6 7^ 9 12 in. height of ash per filter 0.00033 0.00049 0.00090 0.00128 0.00190 0.00230 0.00361 0.00528 0.00927 grms. 3d. 3d. 4d. 6d. 8d. 9d. 1/9 2/- 2/9 4/6 6/- 7/- 646 English Grey Cut Filters. Diameter . . 2j 2| 3f 4^ 5j 6 3d. 3d. 4d. 6d. 8d". 9d. 1/9 21- 2/9 4/6 6/- 7/- lid. 8/3 1/2 ll/- 1/8 per 100. 15/- per 1,000. 7* lid. 8/3 9 1/2 III- 647 Filter Paper, German, soft and quick filtering, 20 by i6J in. per quire, I/- ; per ream 2647 Filter Paper, German, lined, close, for fine precipitates, zo\ by 18 in. per quire, I/- ; per ream 2647 Filter Paper, English, grey, for oils, 24 by 24 in. . . . . „ 2/- ; „ 2647 Filter Paper, English, white, quick, 24 by 24 in., same quality as cut filters No. 2645 per quire, 1 /6 ; per ream 12 in. 1/8 per 100 filters. IS/- per 1,000 filters. £0 18 0 £0 18 £1 16 £150 2648 Charles Schleicher & Schull's Rhenish Filtering Papers. Agents: BAIRD & TATLOCK (LONDON) LTD. AT MILL PRICES, NETT FOR QUALITATIVE WORK. 48T Schleicher & Schull's No. 595 in Sheets. A good light paper, free from chlorine, and tasteless, made of the best material, specially selected for the purpose. A filter of 15 centimetres diameter filters 100 cubic centimetres of water in 50 to 80 seconds. T , 1 ) 47 by 54 centimetres ) Price 25/- per ream. "1 i8fby2i|in. } „ 1/6 per quire. Prices of circles, see page 51,6. ^CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 515 2 L BAIRD &TATLOCK (LONDON) LTD. 2649 2649T Circular Filters, Schleicher & Schull's, 595, with special surface. Diameter in centimetres 4-25 5-5 7 9 ii ,,5 1 , Weight of ash of one filter, grammes Price per 1,000 100 2/9 4d. 0.00036 2/9 4d. 0.00059 3/- 4d. 0.00098 4/- 5d. 0.00146 4/9 6d. 0.00189 o.cx 5/- 7 7d. • Diameter in centimetres 18.5 21 24 27 32 38 31, Weight of ash of one filter, grammes Price per 1,000 . . 100 0.00418 8/9 l/- 13/6 1/6 15/9 1/8 221- 2/5 26/10 2/11 2650T Filter Paper. Soft. Schleicher & Schull's, 604. This paper is similar to No. 597, but has the additional advantage of possessing rapid filtering in the highest degre all cases where quick working is desired this paper is most applicable, of course on condition that the precipitate to be f rred is not of the nature of those which, on account of their fineness, would pass quicker, and therefore require a closer and 'der paper (see Nos. 2651 and 2656). 8^ ^ centimetres) Price 46/- per ream. 2jby22fm. ) „ 2/6 per quire. In sheets of 265 It Filter Paper in circles. Schleicher & Schull's, 604. Diameter 5.5 7 9 11 12^ -15 i8£ 24 27 32 38^ 50 cm. Price 5d. 5d. 7d. lOd. lOd. I/- 1/4 2/1 2/9 3/4 4/5 7/6 per ic 3/10 4/- 5/10 7/3 7/6 9/6 12/6 19/- 25/- 30/6 40/- 66/- per i, : 2652T Frosted Hard Filter Paper. Schleicher & Schull's, 602. In sheets of J58_by 58 centimetres ) Price 46/- per ream. \22-f by 22 Jin. f „ 2/6 per quire. The special feature of this paper is its density and hardness ; the finest precipitates which no other papers can filter ; tained ; consequently this paper must not be expected to filter rapidly, and for this reason we would recommend them to b ( in connection with filter paper or as folded filters. CROSS STREET • HATTOTST GARDETST, E-C 516 BAIRD &TATLOCK (LONDON) LTD. 2f3T Filter Paper. Schleicher & Schull's, 597. A stouter paper than the foregoing, perfectly white and clean, filters notwithstanding its thickness vd' quickly. 100 cubic centimetres of water pass through a plain filter of 15 centimetres diameter in|o to 80 seconds. It is a standard quality for analytical purposes. In sheets of!58 b^ ?8 centimetres \ Price 46/- per ream. 22* by 22'£ in. 2/6 per quire. 26 ^ Circular Filters. Schleicher & Schull's, 597. 2654 \ 1 i ameter in centimetres . . 4 5-5 7 9 ii 12-5 .•ight of ash of one filter, grammes ice per 1,000 . . „ IOO 3/10 5d. 0.0007085 3/10 5d. 0.001144 4/- 5d. 0.001897 5/10 7d. 0.002843 7/3 lOd. 0.003659 7/6 lOd. imeter in centimetres 15 18.5 24 27 32 38.5 50 V 1 ight of ash of one filter, grammes :e per 1,000 . . ,, IOO 0.00527 9/6 I/- 0.00802 12/6 1/4 19/- 2/1 251- 2/9 30/6 3/4 4ft/- 4/5 66/- 7/6 26 -• Filter Paper. Schleicher & Schull's, 591. In sheets of-f54 by s8 centimetres) Price 60/6 per ream. (2ijby22jin. j „ 3/9 per quire. Phis is a specially heavy and strong paper, and is better adapted for the filtration of liquors, fruit-juices, and oils than any other on the market, •iltering with constant rapidity, it does not give off any particles to the filtrate. 2<.!> Filter Paper. Extra Thick. Schleicher & Schull's, 598. In sheets of 1s8 bv 58 centimetres ) Price 78/- per ream. 31(22f by22|in. } „ 4/6 per quire. < TV much in favour on account of its thickness and softness, it is employed when fine precipitates have t retained, or larger quantities of precipitates are to be washed. This paper even retains sulphate of barium ly precipitated, and filters rapidly, irrespective of its thickness. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 517 BAIRD &X\TLOCK. (LONDON) LTD. -**1*— e^S ST 26571 Circular Filters. Schleicher & Schull's, 602. Diameter in centimetres 5-5 7 9 II 12.5 15 18.5 24 27 32 38.5 50 Price per 1,000 6/3 6/7 9/7 11/8 12/3 15/7 20/8 31/2 41/3 50/3 66/- 108/10 „ 100 .. 8d. 9d. I/- 1/4 1/5 1/9 2/4 3/5 4/6 5/6 7/3 11/10 2658T Filter Paper, Free from Starch. Schleicher & Schull's, 581. Tn sWt* nf 1 4° by 5» centimetres} Price 46/- per ream. D1U5f byigf in. J „ 2/6 per quire. As nearly all filtering papers contain starch, which is troublesome in some analyses — especially in such with carbohydrates — we have since January, 1892, introduced a paper which is made of a material entirely free from starch. The before -mentioned qualities are all hand -made papers thoroughly exposed to the frost during the last winter season, so as to secure the highest degree of rapid filtration and closeness of texture. 26591 No. 601. Paper for Drop Reactions. , (22 by 14 centimetres) Price 30/- per ream. In sheets of )8j ^ 5! in. ) „ i}8 per quire. The peculiar composition and texture of this paper has been found by prominent chemists to be most suitable for drop re. actions. It possesses the property of absorbing a drop rapidly without allowing the same to spread too much, thus giving a much more exact absorption in the analysis of ferro- and ferri-cyanides, phosphoric acid, zinc, iodine, etc., etc., than would be the case by using porcelain plates as heretofore. (By a drop reaction it is meant that, for convenience and saving of test material, a drop of the liquid to be tested is dropped on the paper, and a drop of the reagent is added to it or dropped alongside of it.) 2660T No. 566. Extra Soft Thick Filtering Paper. In rolls of 25| in. wide and 55 yds. long . . . . price per roll, 12/6 The great difficulty connected with the nitration of tinct. rhei vinos, tinct. rhei aquos, and solutions of extracts, etc., induced us to make a continuous filtering paper on quite a new system, and after overcoming a great many obstacles, we have succeeded in producing a paper which answers the above purpose in every respect, and according to the judgment of practical men of eminent reputation, we offer the best which has ever been brought into the market for this particular purpose. 2661 Filters, Schleicher & Schull's, Brand No. 589, washed with hydrochloric and hydrofluoric acid for analytical work. 2661T Black Ribbon. 589. Diameter in centimetres 5-5 7 9 ii 12.5 15 Weight of ash of one filter, grammes 0.00004 0.00007 O.OOOII 0.00017 0.00021 0.00025 Price per 1,000 15/- 16/- 24/- 29/- 32/- 38/- „ 100 1/8 1/9 2/8 3/2 3/6 4/2 This brand — black ribbon — is soft and of a very loose composition ; it therefore niters very quickly. Filters made out oi this material are used for such deposits which do not pass .through easily, such as is the case with most metals. For this reason these filters have been found specially adapted for use in laboratories for metallurgy. For BaSO^ and similar deposits passing through easily these niters should not be used. laT w\ BAIRD &TATLOCK (LONDON) LTD. i 2662* White Ribbon. 589. Most saleable kind. Prices same as No. 2661. The filtering speed of the white ribbon brand and its capacity to retain deposits is such as appears to be requisite for most i analytical purposes. We therefore always deliver this brand unless otherwise ordered. The filters made out of this material filter quickly and retain a properly treated deposit of BaSO4. 2663* Blue Ribbon. 589. Price same as No. 2661. This brand — blue ribbon — is made from close, firm material. Consequently these filters must not be expected to work quickly, for which reason it is best to use them when an air-pump is employed, or if possible, as folded filters. They are suitable for the finest precipitations or opaqueness which is not kept back by the brands black ribbon or white libbon. 2664* Yellow Ribbon. 589. Diameter in centimetres 5-5 7 9 it 12.5 15 Weight of ash of one filter, grammes O.00002 0.00003 0.00005 0.00007 0.00009 0.00013 Price per 1,000 18/- 20/- 30/- 36/- 40/- 48/- „ 100 .. 21- 2/2 3/3 3/11 4/4 5/3 The filters of this brand are identical with white ribbon quality. But after being freed from mineral con- stituents, they are also scoured with ether. 2665* Filters washed with HC1 and HF1. Schleicher & Schull's, 590. These niters, which are also treated with HC1 and HF1, are thinner than the brands specified under No. 589. They therefore contain slightly less ash and filter slower than No. 589, white ribbon, but otherwise well retain fine precipitates. Diameter in centimetres 5-5 7 9 ii 12.5 15 Weight of ash of one filter, grammes O.OOO02 0.00003 0.00005 0.00007 0.00009 0.00013 Price per 1,000 18/- 20/- SO/- 36/- 40/- 48/- ,,100 2/- 2/2 3/3 3/11 4/4 5/3 In consequence of the treatment with HC1 and HF1, any soluble mineral matter is extracted from these filters, which probably represent the purest form of cellulose. That the mineral constituents cannot be entirely removed is confirmed by our numerous experiments, and particularly also, by those made by Mr. W. Lange (Reports of the German Chemical Society of the year 1878, P- 323 — " The Nature of the Silicides found in Plants "). He also treated linden-bast successively with HC1, KHO, and boiling alcohol. Cellulose thus treated and purified he dissolved in ammonic oxide of copper ; he then filtered and precipitated with HC1, and several times repeated this process of dissolving, filtering, and precipitating. Notwithstanding this exhaustive process, the ashes proved not to be free of SiO?, CaO, and Fe.,0.,. Nearly half of the ashes consisted of SiO,, such as we have also found to be the case when making our experiments, and which is confirmed by the periodical control of our chemist. Mr. Fresenius (Zeitschrift fur analyt Chemie, 1883, p. 241) has also examined these filters treated with HC1 and HF1, and points out that the weight of the filter-ash of this make is so small that it need not be considered even in exact analyses 2666* Filter Paper Clippings, of 589 chemically pure paper perlb. £016 i |C EMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 519 BAIRD ^TATLOCK (LONDON) LTD. 2667 2667T Folded Filters (special surface). Schleicher & Schull's, 588. For general use, for the filtration of solutions, slightly sweetened spirits, etc. Diameter in centimetres 12.5 15 18.5 24 32 38.5 50 Price per 1,000 100 .. Capacity of the corresponding funnel, grammes 9/10 1/2 60 12/3 1/6 no 15/4 1/10 200 221- 2/8 450 35/2 4/4 740 46/2 5/6 i, 800 72/7 8/6 4,000 The three largest sizes of these niters can be furnished with parchmentised points, so as not to break under considerable pressure. They are numbered No. 580, and sold at the following prices : — 2668T Folded Filters. Parchmentised Points. Schleicher & Schull's, s8o. Diameter in centimetres 32 38.5 50 Price per 1,000 ,, IOO 44/- 551- 6/4 82/6 9/4 They are specially adapted for filtration of molasses, fruit-juices, liquors, etc. 2669* Thick Folded Filters. Schleicher & Schull's, 584. These niters are unsurpassed in supplying all the demands which can be made for clear and rapid filtering combined. Diameter in centimetres 18.5 24 27 32 38.5 5« Price per 1,000 . . IOO 24/- 3/- 30/- 4/- 40/- 5,1- 50/- 6/- 90/- 101- 110/- 12/- CROSS STREET • HATTON GARDETST, E-C RAIRD &TATLOCK (LONDON) LTD. 2670T Folded Filters. Schleicher & Schull's, 572}. These retain the finest precipitates and are mostly used for the filtration of greasy oils, syrups, liquors, and are specially adapted to clarify unsweetened juice of raspberries and thick wine. Diameter in centimetres 15 18.5 24 32 40 5» Price per 1,000 ,,100 24/- 3/- 37/4 4/2 50/7 5/6 721- 7/10 791- 8/8 124/- 13/7 2671T Hard Folded Filters. Schleicher & Schull's, 605. This paper is distinguished by its especial density and hardness. Hence its useful employment. The finest particles or precipitates which no other papers can filter are retained. Diameter in centimetres 12.5 18.5 24 32 38.5 50 Price per 1,000 ,,100 17/4 1/10 271- 3'l- 38/6 4/10 61/7 6/10 80/10 8/10 137 f - IS/- 2672r Filter Paper. Schleicher & Schull's, No. 12. Deeply lined, suitable for rapid filtration. Size, 22i by 22^ in. per quire, 2/- ; per ream £1 15 0 26731 Round Filters. C. S. & S., No. 551, of Deep Black Filtering Paper. D.R.P. 190145 and D.R.G.M. 314123. Th;s new filter, wh:ch has been manufactured since March, 1908, will be a welcome help to the analyst for filtering light coloured sed'ments and for drop reactions of the same nature. On this black paper the most minute traces of a light coloured sediment arc j easily perceptible, consequently not only the complete removal of such sediment is considerably easier, but it only requires a small quantity of solution. The black niters are not acted upon by water, alcohol, ether, diluted acids, or alkalies. Diameter in centimetres 5-5 7 9 ii 12-5 15 18.5 ,, inches 2i 2j 3l 4l 5 51 7i Price per 1,000 6/3 6/7 9/7 11/8 12/3 15/7 20/8 100 8d. 9d. l/- 1/4 1/5 1/9 2/4 2674T Hardened (Toughened) Filters. Schleicher & Schull's, 575. The new thin hardened niters, No. 575, are especially adapted for use with the filter pump, as they cling closely to the sides ', of the funnel. These hardened filters will retain the finest precipitates, and resist pressures of two or three atmospheres when wet. Another important feature is durability in continued use, being available for several operations, as the precipitate can be scraped off without removing the fluff from the filter. They are probably the only papers which are suitable for the filtration of caustic liquids, requiring a long time to deposit, such as solutions of bichloride of tin (SnCl,), chloride of antimony (SbCl3), also acids and strong alkalies. The small sizes, 4 to 7 centimetres, of these filters are particularly useful as a substitute for the expensive platinum cones. , and can be used as supports or under-filters, and by so doing prevent the misfortunes attending the bursting of the large folded | filter papers. We supply the filters, No. 575, in round discs of the following diameters and prices : — Diameter in cm. 4 5-5 7 9 ii 12.5 15 18.5 24 27 32 38-5 50 Price per 1,000 121- 151- I*/. 241- 29 /- 32/- 38/- 49 /- 761- 100/- 122/- 160/- 264 /- „ 100 1/4 1/7 1/9 2/8 3/2 3/6 4/3 5/6 8/6 ll/- 13/6 17/6 29/- ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICAL, 521 BAIRD & TXTLOCK (LONDON) LTD. 2675 2675r Fat-Extracted Paper for Milk Analysis (Adams' method). Schleicher & Schull's, 571. A. Box of 100 strips, 560 by 65 millimetres B. Box of 25 „ £0 8 ( £0 2 ( 2676 2677 2676T Paper Trays, for drying crystals. Schleicher & Schull's, 576. Messrs. Schleicher & Schull have manufactured above since March, 1898 ; they are of the purest qualit\ filter paper, no by 3 millimetres thick, the depression in centre measures 60 by ip millimetres. They serv to thoroughly dry small quantities of crystals from the water of crystallisation. Price, 7/6 per box of twenty-five trays. 26771 Suction Cups. Schleicher & Schull's, 599. These are made of the same material as extraction cups No. 603 (see No. 2557), and are for use wit porcelain suction filters. They are packed in boxes with sliding lids, twenty-four cups in each box. 95 by 30 millimetres . . 150 „ 30 2678T Diffusion Shells. Schleicher & Schull's, 579. These shells are far superior to the parchment paper, be it in the shape of a hose or in connection with glass cylinders. With the very smallest volume they offer the largest possible surface, enabling work to be carried on with the smallest outside vessel, combining greatest cleanliness with absolute reliability. Our dialysing shells are for this reason exceedingly valuable for experiments in the digestion of substances such as albumin bodies, serum, in isolating poisonous substances from secretions and excretions. Packed in boxes with sliding covers containing twenty-five shells. 100 by 16 millimetres 100 „ 40 per twenty-four cups per twenty-five shells £0 £1 CROSS STREET • HATTOTST GARDE1ST, E-C 522 BAIRD &.TATLOCK (LONDON) LTD. 267V 2681-2682 2683 2684 679T Filter Cones, Schleicher & Schull's, 574, made of hardened paper No. 575. It is a well-known fact that funnels of perfect form and correct angle to fit the niters faultlessly are most difficult to produce. i filtering witli the aspirator or pump, air channels are formed between the irregular sides of the funnel and the paper, rendering ic suction almost useless. By means of our new semi-circular filter cone these difficulties are overcome. The paper is folded as shown in sketch (the overlapping part is outside). The cone so formed is placed in the funnel under ic point of the regular filters. On aspiratine, the cone will form a tight seal (much more perfect than the platinum cone between ic filter paper and the wall of the funnel), preventing passing of air or precipitates poured over the edge of the filter. Chemists will readily recognise the real practical convenience of these cones. Being made of the hardened paper No. 575, icy will stand without further protection the pressure of the atmosphere caused by use of the pump. These semi-circular discs for filter cones are furnished in the following sizes : — Diameter in centimetres 5-5 7 9 ii 12.5 15 18.5 24 Price per 1,000 ,, 100 13/3 1/5 14/3 1/7 19/9 2/2 24/2 2/8 26/5 2/11 31/10 3/6 40/8 4/6 62/8 6/11 6801 Filter Hats, Schleicher & Schull's, 577. The hats are made in one piece seamless, and fit exactly into a funnel of 60 degrees. They are eminently lapted for filtering greasy and ethereal oils, spirits, salt solutions, etc. Length in centimetres . . 6 8 10 12 14 16 20 25 Price per 100 .. ..5/3 6/1 6/4 8/6 9/10 11/7 15/5 18/8 581T Rumpler's Filtering Cups, No. 552, manufactured by Messrs. Carl Schleicher & Schull, for use with Gooch's Crucible . . . . . . Price per box of twenty-five cups i82T Gooch's Crucibles, of Royal Berlin Porcelain, 67 mm. high by 32 mm. diam. at top, for use with above . . . . . . . . . . each, 2/- ; per doz. )83T Filtering Apparatus, Witt's, with lid and funnel ground to fit, for rapid filtration by means of water pump. Height of glass cylinder . . . . n 14 16 cm. Inside diameter of cylinder . . . . 7 9 n cm. Diameter of funnel . . . . 4 5 6 cm. Price . . . . . . . . 8/- 9/- 10/- each. £080 £130 )84T Filter Flask, with stopcock on side tube. Capacity Price 2 litres. 5/- each. 523 CT BAIRD &TATLOCK. (LONDON) LTD. 2685-2688 Pyramid Laboratory Filter Presses. GENERAL DESCRIPTION. The " Pyramid " Filter Press derives its name from the studded or bossed drainage surface of the filter plates which suppor the cloths. This is found in practice to be much more efficient than a surface formed of fine ribs, for they allow a sufficient suppor to the cloths under pressure, and also a free passage for the filtrate and wash water. This gives the largest practical area of th filter cloth with a condition of maximum efficiency, filtering from 15 to 35 per cent, more rapidly than the older forms of drainag surface ; also this form of drainage surface is superior to a surface of perforated wrought iron or steel plates, which rapidly corrode forming a couple with cast iron. Another advantage is that the " Pyramid " drainage surface is much more easily cleaned. FLUSH PLATE AND DISTANCE FRAME TYPE. The distinctive feature of the construction of the cells in this type, which are made up of solid slabs, is that the rims < flush with the pyramid-studded face for drainage at the back of the filter cloths to take away the filtrate, not recessed, the dept of the chambers being made up by a separate distance frame, which fixes the depth of the filter cell and thickness of the filter cak formed. They are constructed as non-washing and perfect washing machines. They make the best form of washing filter press, giving the most concentrated washings. The feed and washing passages are formed in the margins of the plates and frames so that no cloth clips are necessary, all joints on the chamber passages and cloths being made secure by tightening up the main screw <•• the machine. . FLUSH PLATE AND DISTANCE FRAME TYPE, PATENT PYRAMID DRAINAGE SURFACES ON THE PLATES. Size. Number of Chambers. Price in Iron, with bronze pump, rubber suction hose air vessel, and pressure gauge for feeding. Price in Acid-resisting brorze, with bronze pump, rubber suction hose air vessel, pressure gauge for feeding. 2685* 2 £12 10 0 £17 6 0 2686* 2687* 6 £14 0 0 £15 0 0 £19 12 0 £21 18 0 2688* 12 £19 10 0 £28 16 0 Plus £1 5s. extra for every additional two Chambers. Plus £2 6s. extra for every additional two Chambers. The abcne prices are exclusive of buckets and nitrate dish. (Prices continued on page 525.) -CROSS STREET • HATTOTST GARDEN, E-C BAIRD &.TATLOCK (LOM)ON) LTD. Extra Distance Frames for altering the Depth of the Filtering Chambers. In Iron. In Acid-resisting Bronze. 2689* E. £ in. Each 4/6 Each 7J- 2690* F. I „ » 6/- ,, 10/- 2691* G. ij „ „ 7/5 „ 12/- 2692* H. 2 „ Q / t> 'I m „ 14/- 2693* Duplicate pump, with rubber suction hose, air vessel, and pressure gauge. For washing, 70/- extra. 2694* Or one pump with two air vessels and pressure gauges, and switch valve provided with rinse through arrangement, extra 120/-. 2695* 2696* Filter Cloths for use with Press. Filter Papers for use with Press. Per Doz. Per Doz. Per Gross. i. Svvansdown 6/6 6. Chain .. 71- i. Plain, single sheets 3/- 2. Super do. .. 91- II. Hydraulic Chain .. 101- 2. Crinkled Paper 3/- 3. Extra Super dc. .. 121- 21. Camel Hair .. 121- (For High Pressure. ) 4. Twill .. 61- 22. Asbestos .. 151- 3. Carbon Paper 3/6 5. Hydraulic Twill .. 11/6 23. Felt .. 10/- 2697* Packing case table provided with lead-lined top and drain pipe, as shown in woodcut, 50/- extra. 2698* Or packing case only for the above machine, 7/6 extra. 2699-2702 Non- Washing Laboratory Filter Presses, complete with pump, accumulator, and pressure gauge, as shown in illustration. Working pressure, 100 Ibs. per square inch. Can be worked with either filter paper or filter cloth. Prices, see page 526. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 525 BAIRD &.TATLOCK. (LONDON) LTD. No. of Chambers. Filtering Area. Capacity in Cubic Inches. Price. 2699T 2 Chambers for J-in. Cakes 210 sq. in. 52-5 £600 2700T „ for 420 „ 105 £700 270 1T „ for i-in. Cakes 210 „ 105 £6 10 0 2702T „ for2-in. „ 210 „ 210 £700 2703 2703T Dr. Gibson's Improved Filtering Apparatus, as used in the University of Edinburgh, complete, with indiarubber corks, etc. Tubulated receiver, 12 by 6| in. . . Brass three-way stopcock Long cylinder funnel . . ...... Short 2704* 2705* 2706* 2707* 2708* 2709* 2710* 2711* Plain funnel, 2 in. diameter . . Stand covered with indiarubber Half bottle.. Filter pump . . • . . The bell-jar A (2703), rests during nitration on a square block (c) of hard mahogany, 25 centimetres square and 25 millimetres thick. The cross pieces (c c) are of the same wood, and prevent warping. Over (c) is laid a sheet of soft vulcanised rubber (D) of good quality, and not less than 3 millimetres thick. In the centre is a circular ' disc (E) also of hard wood, 13 centimetres in diameter, and about 20 millimetres thick, which is held in position by four strong brass screws, which pass down through the rubber into the square block below. In (B) is fitted a single-bore rubber cork holding the brass tap (F) . This tap is simply an ordinary brass tap, converted into a three- way tap by boring a hole (s) through one outer wall and through one wall of the plug. It enables the operator to establish communication between — (i) The bell-jar and pump ; (2) the outer air and both bell-jar and pump ; (3) the outer air and pump, the bell-jar being shut off ; (4) the cuter air and bell-jar, the pump being shut off. After fitting in the cork and tap, the knee-piece (H) is screwed on. If the mouth (A) be closed by a rubber stopper, and the tap (F) connected by a rubber tube with a water-pump or otherexhausting apparatus, as the pressure inside diminishes, the rubber sheet bulges up inside the bell-jar, and, pressing against the lower edge, closes up any interstices due to irregularity on its own surface, or to imperfect grinding of the glass. A well-made water-pump will give within half-an-hour a high degree of exhaustion, and this without the use of any lubricant whatever. Where a very high degree of exhaustion is required, the application of a little grease outside, round the lower edge of the bell-jar, is advisable. The funnel is supported by a small conical rubber stopper (i) in the upper and enlarged end of the tube (K), which is in turn supported at the mouth (A) of the bell-jar by the larger rubber stopper (L). The hole in this stopper should be sufficiently wide to permit of the glass tube (K) sliding easily up and down in it. The lower end of the tube should be ground off at an angle, and bent as shown in the figure. It is then easy to bring the end of the tube in contact with the side of the vessel in which it is desired to collect the filtrate, and thereby to entirely obviate any danger of loss by spurting. £1 £0 £0 £0 £0 £0 extra £0 3 CROSS STREET • HATTCHSr GARDETST, E-C 526 RAIR.D &TM1OCK (LONDON) LTD. Before commencing operations it is well to slightly moisten the rubber sheet (D) with water. This is not by y means absolutely necessary, but causes a quicker gripping of bell-jar and rubber. The tap being in position i. 2, and connected with a water-pump in full action, filtering is commenced by first filling up the filter nearly full tli the liquid to be filtered, and then establishing communication between the pump and the bell-jar by turning e tap to position No. i. During the operation of transferring the precipitate on to the filter it is often necessary lessen the rate of filtration by diminishing or destroying the difference of pressure outside and inside of the bell- i This can be quickly and easily done by giving the tap a half turn back to position No. 2, and thus allowing r to rush in both to the pump and to the bell-jar. The use of the knee-piece (H) will be now apparent, for by it r inrush of air is diverted away from the vessel inside, which might otherwise be blown against the side of the 11-jar and upset or broken. As it is, however, the vessel inside is not at all affected by the inrush of air, however ddenly the tap be opened. 2712 712 Filter Drainers, German Porcelain. Diameter . . . . 10 Price .. .. 7d. ..6/6 713 Soxhlet's Filter Tube, for use with asbestos 2713 12 10d. 9/6 14 1/6 171- 15 1/10 21/- 17 2/9 32/- 2714 20 centimetres. 3/3 each. 37/- per doz. each £006 714 Filtering Tubes, stoppered, with perforated bottoms, for reducing and weighing the Cu20 in sugar estimations . . . . . . . . . . . . each £0 1 9 2715A 2715s 2715c 7 15 Glass Flasks, of best-quality Bohemian Glass, well annealed. (Forms A, B, and C same price.) Capacity Price Capacity Price Form A. „ B. C. I 8d. 7/6 30 3d. 1.25 9d. 8/6 60 3d. 2/3 lid. 9f- 125 3d. 2/6 2 I/' 10/6 175 4d. 2-5 1/3 13/- 250 4d. 3/6 3 1/3 14/- 300 5d. 3-5 4 1/6 21- 171- 211- 350 6d. 5 2/6 28'- 500 6d. 5/3 7 3/9 42/- 625 7d. 5/9 9 10 4/3 4/8 48/- 52j- 750 c.c. 7d. each. 6/- doz. 14 litres. 5/6 each. 60/- doz. Bulb-shape turned-over necks. All sizes listed kept in stock. Welted necks. Sizes up to 2 litres only kept in stock. Round bottoms, turned-over necks. Sizes up to 2 litres only kept in stock. 'CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 527 RAIRD &TATLOCK. (LONDON) LTD. WARRANTED QUALITIES OF "RESISTANCE" GLASS. We offer full guarantee that our " Resistance " Glass, lately again improved, is not surpassed by any other glass on the market in resisting sudden changes of temperature and the action of hot water as well as of corrosive chemicals. No solution of glass can be detected, and beakers or flasks may be used with naked flame of a Bunsen burner without risk of breakage. The articles made of this glass are well finished and will prove to be considerably larger than stated, the capacity indicated filling the vessels only up to 2,'3rd — 3,4th of the height and not up to rim as frequently in practice. I B T I All vessels bear the registered trade mark R in circle, our \,J brand and the capacity in ccm. stamped on ; apparatus, etc., made of tubing show blue stripes. \s Inferior imitations being sold, precaution is necessary in purchase. In glass of ordinary quality it is found that nearly always about 200 — 400 thousandths of a mg. of constituent matter are dissolved out of a surface of 100 cm. square. The insolubility of our " Resistance " glass has reduced this to I-^JTF of a mg.in cold water andTJ£,jmg. in hot water. (See Certificate of Reich's- Anstalt, Charlottenberg.) 2716 2716 Flasks of " Resistance " Glass, with flat bottoms, each marked with and our brand and Flasks made in this quality of glass are specially recommended for use in tropical climates as very infusible, and as a rule withstand sudden variations of temperature without cracking. Capacity 60 125 175 250 350 500 750 1000 1500 2000 3000 c.c. Price 3d. 3d. 4d. 4d. 6d. 7d. 8d. lOd. lid. 1/1 1/4 each. 2/6 2/9 3/3 3/6 4/9 6/- 7/- 8/6 9/6 11/3 14/9 per - 2717 2717 Flask of" Resistance " Glass, with three necks. The middle neck may be used for the insertion of a stirre or condenser, the smaller necks for funnel or thermometer. This flask will prove very useful for the organic analysis, etc. Capacity .. .. .. .. I 2 litres. Price 2/3 2/9 4/3 each. CROSS STREET • HATTON GARDETST, E*C 528 BAIRD &TATLOCK (LONDON) LTD. 2718 2719 2718r Flasks, flat-bottomed, new Jena Glass. Capacity 50 100 150 200 300 Price 3d. 2/6 100 3d. 2/9 4d. 3/3 200 4d. 3/9 5d. 4/6 400 6d. 5/6 2720 500 7d. 6/3 2721 700 8d. 7/6 1000 lOd. *!' 1500 I/- III- 2000 1/2 12/6 3000 1/6 16/3 2722 4000 c.c. 2/3 each. 23/- per doz. 4 litres and above are supplied only with welted necks. Larger sizes than quoted to order only. J719T Flasks, round-bottomed, new Jena Glass. Capacity 50 100 150 200 300 400 500 700 1000 1500 2000 Price 3d. 3d. 4d. 4d. 5d. 6d. 7d. 8d. lOd. I/- 1/2 2/6 2/9 3/3 3/9 4/6 5/6 6/3 7/6 9/- 11 f- 12/6 4 litres size and above supplied with welted necks to order only. 3000 c.c. 1/6 each. 16/3 per doz. 1720 Filtering Flasks, of heavy glass, conical, stout glass with side tube, for connection to filter pump. Capacity Price 125 6d. 5/6 250 8d. 7/6 500 lid. 10/- 750 c.c. 1/1 12/- 1721 Filter Flasks, with widened neck for funnels. Capacity Price i 1/4 15/- i lid. 10/6 22/6 *i 34/- i 1/3 14/- Hollow Indiarubber Rings for above, 4d. each. 722 Diamond's Filtering Flasks. See Chemical News, Vol. 74, No. 1933, p. 283. Capacity . . . . . . . . . . . . £ Price .. .. .. .. .. .. ..9/6 3 litres. 4/6 each. 52/- per doz. i litre. 2/- each. 23/- per doz. i litre. 12/- each. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 529 BAIRD ^IXTLOCK (LONDON) LTD. \ r\ 2723 2724 2725 2723 Wash Bottle, fitted with ground stopper and tubes. Capacity Price 250 1/9 500 21- 1000 C.C. 2/9 each. 2724 Washing Flask, with stopcock on each tube, ground stopper for use with ether, carbon bisulphide, etc Capacity . . . . . . . . . . . . . . 250 500 c.c. Price . . . . . . . . . . . . ..51- 5/6 each. 2725 Washing Flask, fitted with two-holed rubber cork and tubes. Capacity . . . . . . . . 500 625 750 1000 1250 c.c. Price .. .. .. .. 1/2 1/3 1/4 1/6 1/9 each. 2726 2727 2726 Flasks, conical, Erlenmeyer's, Bohemian Glass. Capacity 60 125 175 250 300 350 Price 3d. 3d. 3d. 4d. 4d. 5d. 2/- 2/3 2/9 3/3 3/6 4/3 500 5d. 4/9 625 6d. 5/6 750 7d. 6/6 2728 1000 8d. 7/6 1500 lOd. 2000 C.C. lid. each. 10/- per do. 2727 Flasks, conical, Erlenmeyer's, " Resistance " Glass. Each marked with and our brand Capacity Price 125 3d. 2/9 175 4d. 250 4d. 3/9 2728T Flasks, conical, Erlenmeyer's, new Jena Glass. Capacity 25 50 100 150 200 250 300 Price 3d. 3d. 3d. 4d. 4d. 4d. 5d. 2/4 2/5 2/6 3/- 3/3 3/9 4/- 500 6d. 5/9 350 5d. 4/9 600 7d. 6/3 500 7d. 750 8d. 750 1000 c.c. 8d. 9d. each. 7/9 8/- perdoz. 1000 1500 2000 C.C. lOd. I/- 1/1 each. 9/- 111- 12/6 per do CROSS STREET • HATTCflST GARDETST, E- C 530 Iff BAIRD &TATLOCK (LONDON) LTD. 2729 2731 2732 2733 2734 2735A 2735B 2729 Flasks, globular (bolt-heads), with welted necks, of strong best quality Soda glass. Capacity . . . . 250 500 c.c. i ij 2 3 5 10 litres. Price .. .. 4d. 5d. 9d. 1/2 1/4 1/7 2/8 4/2 each. 3/9 4/6 8/6 13/- 15/- 18/- 30/- 48/- perdoz. 2730 Flasks, of specially hard infusible Bohemian glass, for preparing oxygen (as Fig. 27150). Capacity . . . . . . . . 60 125 175 250 350 500 c.c. Price .. .. .. .. 6d. 9d. lOd. lid. I/- 1/3 each. 2731 Bolt-head Absorption Tubes, for gases, as used in Royal Naval College, 24 oz. bulb, neck 24 by i in. . . . . . . . . . . . . . . each £0 1 6 2732 Flasks, parting, for assaying, bulb form. Capacity Price " Resistance I glass. i 2/3 2 2/6 4 oz. 3/6 per doz. 2733 Flasks, assay, for parting, conical, with ring of glass on outside at top. Best Bohemian glass. Capacity . . . . . . 2 . . 4 6 8 10 12 16 oz. Price .. .. 3d. 3d. 4d. 4d. 5d. 5d. 7d. each. 2/6 2/9 3/6 3/9 4/6 4/9 6/6 per doz. 2734 Flasks, parting, stoppered, for silver assay, as used in the Bombay Mint. Capacity, 360 cubic centimetres, flasks and stoppers numbered 2735 Flasks for Kjeldahl's apparatus, round bottom, new Jena Glass. With long necks. A. Capacity . . . . . . 200 300 500 Price .. .. 5d. 7d. 9d. 4/9 6/- 8/- 2736 Glass Stoppers for Kjeldahl's flasks each, 1/6; perdoz. £0 17 6 With short necks. B. 200 300 500 c.c. 5d. 6d. 8d. each. 4/3 5/3 7/3 per doz. . . per doz. £019 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 531 2M BAIRD &.TXTLOCK (LONDCfN) LTD. 2737 2738 2737 Flasks, finest Bohemian glass, with short wide necks, for fat extraction apparatus, etc., necks 25 mm. diameter. Capacity 30 60 90 125 175 250 c.c. Price 2d. 3d. 3d. 3d. 4d. 5d. each 1/9 2/3 2/6 2/9 3/6 4/- per . 2738s Flasks with short wide necks for fat extraction, new Jena glass. Capacity . . 50 100 150 250 500 c.c. Price .. 3d. 4d. 4d. 5d. 8d. each. 2/9 3/- 3/6 4/6 7/- per . 2739 2740 2739 Flasks, round bottom, " Resistance " glass, with side tube for fractional distillation. Capacity . . . . 50 100 ' 250 500 750 1000 c.c. Price . . . . 5d. 7d. lOd. I/- 1/4 1/8 each. 4/6 6/6 9/6 ll/- 15/- 18/- per doz. 2740 Flasks, round bottom, " Resistance " glass, with side tube, stoppered. Capacity . . . . . . . . . . 500 750 1000 Price .. .. .. .. ..1/6 2/- 2/6 2741 Distillation Flasks, " Resistance " glass, stoppered, with side tube bent at right angles and ground to fit condensers No. 2238. Capacity of flask . . . . . . . . 4 i 2 litres. Price .... .. 9/6 ll/- 13/- each. 2OOO C.C. 4/6 each. CROSS STREET • HATTCnST GARDEN, E-C 532 BAIRD &TATLOCK (LONDON) LTD. 2742 A2742 B2742 '42 Flasks, for tractional distillation, best quality Soda glass, well annealed, with side tube fused on at centre of neck. Capacity . . 30 60 125 250 350 500 750 c.c. i ij 2 litres. Price .. 3d. 4d. 5d. 7d. 9d. lOd. I/- 1/3 1/9 2/6 each. 2/9 3/6 4/- 6/- 8/- 9/6 11/6 14/- 20/- 29/- per doz. 742 Flasks, for distillation of oils, standard size, designed by Engler, 742 Flasks, for distillation of essential oils, Scliimmel's standard pattern, j glass each, I/-; per doz. £0 11 6 i glass each,2/-;perdoz. £130 2743 2745 Flasks, porcelain. Capacity Price 150 1/6 2746 250 grammes. 2/- each. • 44 Anschutz's Flasks, for distillation under reduced pressure. See Nos. 2302-2303. 45» Flasks, copper, with brazed joints, for fractional distillation, 300 c.c. . . each Flasks, copper, for generating oxygen, all joints brazed £0 12 0 £0 12 0 533 BAIRD SdATLOCK. (LONDON) LTD. 2747 2747^ Flasks, stout brazed copper, tinned inside, flat bottom. Capacity . . 4 8 16 Price .. 4/6 5/6 7/6 2749 32 12/6 2750 48 oz. 15 1 - each. 2748 Flasks, thick glass, widened at mouth, " wine flask," roughly graduated with mark on neck. Capacity . . 100 250 500 750 1000 c.c. Price .. 3/6 4/6 5/6 8/- 9/6 per doz. 2749 Forceps, brass, nickel-plated . . . . . . each £0 0 2750 Forceps, brass, with ivory points 2753 2751 Forceps, steel, fine points 2752T Forceps, steel, with platinum points, price variable . . 2753T Forceps, steel, with solid platinum shoes, price variable 2754 2754 Forceps, with glass arms, and nickel-plated metal strip to connect each, 2/- ; per doz. £1 (For other pattern forceps see Nos. 1485-1505). CROSS STREET • HATTCnST GARDETST, E-C 534 BAIR-D &TATLOCK (LONDON) LTD. 2755 2755H 2755J 2756 755» Beckman's Apparatus for the Estimation of Molecular Weights, Boiling Point Method. Complete as detailed below, A. to F. . . A. Thermometer graduated into 6° C. in T^yths of a degree (see page 536) . . B. Boiling vessel, with platinum wire C. Asbestos cover, garnets, etc. D. Tripod stand 2757 £2 12 0 £150 £0 10 6 £066 £056 £020 £056 £0 15 0 £100 £090 E. Pipette, etc. F. Nickel-plated ball condenser G. With precision stopcock . . . . . . . . . . . . extra H. Steel mould, new pattern .. .. .. .. .. .. „ J. Steel mould, simple form (See Zeitschrift fur Physik Chemie, iv., 5, 544.) 756s Beckman's Improved Boiling-Point Apparatus. Complete, as detailed below, A. toG. A. Thermometer, 6° C. graduated into Tiffths of a degree (see page 536) B. Asbestos air bath C. Glass steam jacket D. Testing tube, with platinum E. Two spiral condensers F. Two small Liebig's condensers G. Garnets, glass beads, pipette, asbestos paper, and fireclay plate (See Zeitschrift fur Physik Chemie, viii., 2, 234.) • 57s Porcelain Steam Jacket for above (for use in place of glass jacket No. 27560) .. £0 17 6 £2 10 0 £150 £066 £0 £0 5 6 4 0 £0 £0 £0 3 0 5 0 4 0 BAIRD &TATLOCK (LONDON) LTD. 2755A 2758 2759-2765 2758s Beckman's Apparatus for the Estimation of Molecular Weights, Freezing Point Apparatus. Complete without stirrer . : A. Thermometer graduated into 6° C. in ^ of a degree B. Glass jar with cover and zinc base and different glass parts, etc. C. Platinum stirrer (price according to weight) . . . . . . . . about (See Zeitschrift fur Physik Chemie, vii., 3, 324.) Beckman's Apparatus for freezing point determinations with stirring arrangement, as modified by Lindeman, for blood and urine examinations. Cooling vessel with nickel plated cover and stirrer, 4 air jackets and freezing tubes for 5-6 c.c. ; corks, etc. Zinc trough with syphon Thermometer for cooling vessel — 20° to + 40° C. in \ Stirring arrangement for either hand or motive power, consisting of stand, with clamp, pulleys, etc. £2 £1 £1 £0 5 1 15 2759* 2760* 2762' 2763" 2764« 2765" Stirrer, glass rod with platinum ring Thermometers, + 0.5 to — 5° C. in + o.5to-5°C.in Certificate for Nos. 2764 or 2765 each each, extra £0 15 £0 3 £0 3 £0 14 £0 17 £1 17 £1 8 £0 7 536 BAIRD &TATLOCK (LONDON) LTD. 2766-2770 2771-2772 2773 2775-2778 2779 766s Beckman's Apparatus for freezing point determinations, for small quantities of about 1.5 c.c. of liquid. Price complete 7678 Cooling vessel, with nickel plated cover and stirrer 7683 Freezing tube with cork ring and air jacket 7698 Stirrer for freezing tube with platinum ring in glass rod 770s Normal Thermometer + 0.5 — 5° C. in fe 771« Beckman's Apparatus for determination of the boiling point, with electrical heating arrangement. The apparatus consists of a Dewar's vacuum flask on wooden sole, with inner vessel and thermometer. Price without thermometer Thermometer extra i° C. in T^j, 773 Roth's Melting Point Apparatus 775s Melting Point Apparatus, Ubbelohde's (as described in Zeitschrift angew, Chemie, 1905, Heft 31), with thermometer, o to 100° C., in single degrees, metal cap, and glass capsule 776s Melting Point Apparatus as above, thermometer, o — 150° C. in single degrees 777" Melting Point Apparatus „ „ 50—250° C. Extra glass capsules for Nos. 2775-2777 . . . . . . . . each The apparatus consists of a thermometer fitted to a metal cap, at the other end of the cap is a second flange irrying the small glass cups, these cups are 10 mm. long, with a 3 mm. hole, and are so fitted that the bulb of the lermometer is placed exactly in the centre. The glass cups are filled with the substance to be tested ; should the substance be of the nature of paraffin or •resin, it should be melted into the cup, and left to set for twenty-four hours. Different cups should therefore s used for each experiment if more than one are required during one period of twenty-four hours. When ready place the cap in position and insert apparatus in a beaker of water, which gently heat. The citing point is the temperature at which the whole contents of the cup runs out. 779 Melting Point Apparatus, with two side tubes with ground on caps. The melting tubes are inserted at the small side tubes, and rest on the glass ring 780 Melting Point Apparatus. Jena glass bulb with sliding sleeve, carrying thermometer o — 250° C. in i°, ground to fit 2780 £2 12 6 £060 £020 £0 17 6 £176 £110 £250 £036 £150 £176 £1 10 0 £020 £030 £076 537 BAIRD &TATLOCK (LOM)ON) LTD. 2781 2781 Walker and Lumsden's Modification of Landsberger's Boiling Point Apparatus, with thermometer 70 to 105° C. in £ths and indiarubber corks (.See Journal of Chemical Society, Ixxiii., 1898, p. 502.) 2782A 2782B 2784 I ii 2 «1 3 3i 4 4» in. 2d. 2d". 2d. 3d. 3d. 3d. 4d. 5d. each. 1/4 1/9 1/9 2/- 2/3 2/9 31- 4/- per doz. 5 6 7 8 9 10 ii 12 in. 6d. 7d. 9d. I/- 1/4 21- 2/9 3/- each. 51- 6/6 8/6 ll/- 15/- 231- 321- 34/- per doz. 2782 Funnels, best clear glass, ground edges, stems cut off at angle, plain A or ribbed B. Diameter Price Diameter Price » * • 2783 Funnels, best Bohemian glass, ground edges, plain or ribbed, correct angle and uniform (A or B form, see Fig. 2782). Diameter i i£ 2j 2f 3! 3f 4^ 4! 5^ 6J 7^ 8£ gi lof in. Price 3d. 3d. 4d. 4d. 5d. 6d. 7d. 9d. lOd. 1/1 1/5 2/3 3/- 3/6 each. 21- 2/6 3j- 3/6 4/- 5/- 6/- 8/- 9/- 12/- 16/- 26/- 35/- 40/- per doz. 2784 Funnels, with bulb in stem, for filtering with glass wool. Diameter Price 4d. 3/6 4 6d. 5/6 5 in. 8d. each. 7/6 per doz. CROSS STREET • HATTOTST GARDE1ST, E-C 538 BAIRD &.TATLOCKL (LONDON) LTD. 2785 2786 : 85 Funnels, heavy glass, deeply fluted, for rapid filtration. 2787 2788 Diameter Price it 7 6d. 5/9 9 7d. 6/9 ii 8d. 7/6 16 . I/- 11/6 24 centimetres. 3/- each. 34/- per doz. ',86 Funnels, light enamelled steel, Diameter Price with handle. . . . 34 8d. 7/6 5J lid. 10/6 7 in. 1/6 each. 17/- per doz. '. 87 Funnels, Meyer's condensing, to invert over evaporating dishes, Diameter . . . . . . . . . . 6 with tubulure. 8 10 12 in. Price .. 1/9 2/9 4/6 5/6 each. ;38 Funnels, thin blown glass, set of three, diameter i to i£ in. 5d. per set. 2789 2790 2 19 Funnels, bulb form, with stopper and stopcock of heavy glass. Capacity . . . . . . 250 500 750 c.c. i Price .. .. .. 3/6 41- 4/6 5/- 0 Funnels, stopper and stopcock, cylindrical form " separators." Capacity . . 150 250 300 500 625 c.c. i ij Price 2/6 2/9 3/- 3/6 4/- 5/- 6/- 2 litres. 6f- each. i£ 2 litres. 6/6 7/6 each. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 539 BAIRD &T&TLOCK (LONDON) LTD. A2790 2791 2792 2793 2794 A2790 Funnels, stopper and stopcock, graduated into cubic centimetres. Capacity . . . . 150 250 500 1,000 Price .. .. 3/9 4/6 5/6 8/9 2791 Separators, conical form, graduated, with stopper and stopcock. Capacity . . . . . . . . . . 100 Price . . . . . . . . . . 3/6 2792 Separators, conical form, with stopper and stopcock. Diameter . . . . . . . . 150 300 Price .. .. .. 3/- 3/6 1,500 101- 150 500 4/6 2793 Funnels, bulb, stopper and stopcock, long stem. Capacity 12468 Price 2/- 2/2 2/4 2/6 3/- 2794 Funnels, with stopcock, heavy glass. Diameter Price 12 3/6 16 3/9 4 3/3 20 4/6 24 6 41- 2795 2796-2797 2798 2799 2800 2,000 c.c. 12/6 each. 250 c.c. 5/- each. 625 c.c 5/- each. 32 oz. 5/6 each. 8 in. 6/- each. 2795 Funnel, cup form, with stopcock, capacity about 100 cubic centimetres each, 2/- ; per doz. £1 3 2796 Funnel, cylinder form, with stopcock, 50 cubic centimetres 2797 Funnel, cylinder form, with stopcock, 100 cubic centimetres 2798 Funnels, safety, thistle head. Length Price » • • • • • • 2799 Funnels, safety, with bend and one bulb, length 16 in. 2800 Funnels, safety, with bend and two bulbs, length 16 in. lid. 1/2 .. 2/-; „ £1 3 „ 2/3; „ £1 6 12 18 in. 2d. 3d. each. 1/6 2/6 per doz. each, 5d. ; per doz. £0 4 6d. ; £0 5 CROSS STREET • HATTON GARDETST, E-C 540 BAIRD &TATLOCK. (LONDON) LTD. 2801 2802 2803 2801 Funnels, safety, with bend and two bulbs 2802 Funnels, safety, with bend and four bulbs 2803 Funnels, white stoneware, fluted inside. 2804 2805 each 8d. ; per doz. £076 9d. ; £086 Diameter Price 2804 Funnels, porcelain, with perforated filter Dr. Hirsch's pattern. Diameter . . . . z Price . . 9d. 3 4* 6 I/- 1/3 2/6 disc, moulded with funnel in one piece, 2f 31 41 4f 51 1/1 1/5 1/9 21- 2/9 12/- 16/- 20/- 23/- 32f- 8J 4/6 6J «/• 47/- in. each. in. each. per doz. 2805 Funnels, porcelain, with perforated plate, Dr. Buchner's pattern. Diameter 2 al 3 4 5 6 8 in. Price 1/3 1/6 1/9 2/2 3/- 3/5 4/3 each. •• 14/- 171- 20/- 25/- 35/- 40/- 50/- per doz. 2806 2807 2806s Funnels, copper, set of three, for filling combustion tubes, diameter i}, 2f, and 3 in. 2807s Funnels, gutta-percha, for acids. .... 2| 4i Diameter Price 1/6 2/6 set £026 5i «n. 3/9 each. 541 BAIRD &TATLOCK. (LONDON) LTD. 2808 2809-2810 2811-2812 2813 2808s Funnel, hot water, double jacket, suitable for funnels from 3 to 6 in. A. Copper, 6 in diameter, without stand B. „ „ „ with 2809s Hot Water Funnel, 6 in. diameter, spun copper, single jacket, with tubulure for filling, legs riveted on, with glass funnel and cork 2810s Hot Water Funnel, 6 in. diameter, spun copper, double jacketed, suitable for funnels up to 6 in. diameter, with tubulure for filling, on stand, with glass funnel 2811s Hot Water Funnels, spun copper, to fit in ring burner, with glass funnel. Single Jacketed. Double Jacketed. Diameter . . . . . . . . . . 4 6 6 in. Price .. .. .. ..5/6 8/- 10/6 2812s Price with burner and stand as illustrated . . 12/6 14/6 17 j- 2813s Funnel, with side gas leading tube . . . . . . . . . . each £0 13 6 15 0 £0 £0 0 10 2814 2814s Steam Funnel, with inlet and outlet tubes, to suit glass funnels up to6f in. diameter, for the hot filtration of inflammable liquids. Price, with glass funnel . . . . . . £080 CROSS STREET • HATTOTST GARDETST, E-C 542 BAIRD &TXTLOCK (LONDON) LTD. Furnaces — Gas, Oil, and Electric. 2815-2816 2817 * 2815s Furnace for heating tubes, designed by Professor Sir W. Ramsay, London, about 7 in. long, with aperture -^ in. at top, which can be closed by sliding covers 2816s Furnace as above, with Bunsen burner, | in. 2817s Furnaces, Erlenmeyer's improved construction, with arrangement for raising and lowering burners. Complete with bricks, etc. Burners fitted with air regulators and lever stopcocks. No. of burners . . . . . . 12 15 20 25 30 Length . . . . . . . . 12 15 20 24 28 in. Price 50/- 60/- 75/- 957- 105/- £076 £0 10 6 2818 2818s Furnaces, Hoffmann's, with perforated clay burners and bricks complete A. 12 stopcocks, 36 burners, 3 rows B. 20 ,, 60 ,. 3 .... C. 26 78 .. .... £400 £500 £600 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 2819 2819s Furnaces, Glaser's, with Finkener's burners, for simultaneous adjusting of air and gas, lever arrangement for raising cr lowering burners. Complete with bricks and iron and fireclay gutters. No. of burners . . . . . . 10 15 20 25 Length . . . . . . 14 20 28 32 in. Price 751- 95/- 120/- 145/- / f ' / 2820 2820s Furnaces, Bunsen's, well finished, stopcock and air regulator on each burner, with fireclay bricks. No. of burners Length Price .*stf^ 12 18 15 24 551- 65/- 26 30 28 32 fn. 90/- 1051- each. ri2 ^^ jiP!"'14' ' CROSS STREET • HATTOTvf ^- l»if' / GARDEN, E-C- Jnj 544 BAIRD &.TATLOCK (LONDON) LTD. 2821 2821s Furnaces, Liebig's, sheet iron, for charcoal, 24 in. . . £046 2822 22T Furnace, similar pattern to Erlenmeyer's, but for use with benzoline. Length about . . . . . . . . . . 16 Price . . . . . . . . ..£710 INSTRUCTIONS FOR WORKING. 24 in. £10 10 The reservoir should be filled with benzoline and connected with furnace trough as shown. Place a small antity of methylated spirits in the metal cups below burners, and when this has burnt away and tubes are hot, Uy open the valve stopcocks, and light the burners. The size of flame can be regulated by these stopcocks. 2823 2823s Furnace for heating tubes, consisting of four f-in. Bunsen burners with regulators, on stand, and adjustable sliding support to hold tubes . . £0 1( Combustion Furnaces and Accessories for Elementary Chemical Analysis, DESIGNED BY PROF. D. M. DENNSTEDT. 2824 2824T Furnace, with fittings, as used by Prof. D. Dennstedt in the Hamburg State Chemical Laboratory. Consisting of a simple combustion furnace, 2 teklu burners, with wide tops, i Bunsen burner, i caustic soda tube, 3 caustic soda U tubes, i CaCla U tube, i stand, i oxygen admission tube with 3 stopcocks, 3 Jena combustion tubes, 2 inner tubes, i glass rod, 2 porous gutters, 3 combustion boats, 2 weighing bottles, I palladium chloride bottle, i nitrometer, i drying tower, 2 aspirator bottles with tubulure, etc. Price complete £6 15 l 2825T Furnace, complete as above, but with spirit Bunsen burner . . . . . . £717 A28251 Platinum Contact Stars, for use with above combustion furnace (price variable) each £0 15 ' CROSS STREET • HATTO^T GARDETST, E-C 546 BAIRD &TATLOCK (LONDON) LTD. 2826 !826T Demisted t's Combustion Furnace, complete as figured, consisting of double com- bustion furnace, etc. £850 2827 827T Dennstedt's Combustion Furnace, complete as figured, with electrical heating arrange- ment, consisting of a long and short electric tubulure furnace, which are so arranged that they slide up and down two rails, two nickel gutters and resistance, but without platinum £18 10 0 828r Platinum for above, 16 grammes required for no volts, 6 amps., or 220 volts, 3 amps., at market rate approximately 208/- per oz. troy. SPARE PARTS FOR FURNACES No. 2824—2827. 8291 Simple Furnace body, No. 2824, consisting of two supports, one set of five iron covers, one fitted with mica window . . . . . . . . . . . . £0 18 6 330* Double Combustion Furnace body, No. 2826, on two stands .. ..£130 331* Bunsen Burner, with air regulator on sole . . . . . . . . ..£040 332* Bunsen Burner, with tube burner . . . . . . . . . . ..£086 S33T Teklu Burner on heavy sole, diameter of tube 13 millimetres, with wide top to burner . . £050 *34* Teklu Burner, fitted with tube burner . . . . . . . . . . ..£096 *35T Dennstedt's Electric Combustion Furnace, without accessories (No. 2827), without platinum, but with resistance arranged for continuous current (no or 220 volts) . . £1510 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. A B 2836 C D 2837 2836T Soda Lime Apparatus after Dennstedt-Klunder, entirely of glass, with ground stoppers. A. B. C. D. 4/6 SI- 51- 51- 2837T Soda Lime U Tube, with ground-in glass stopcock . . 2838T Calcium Chloride U Tube, with ground-in glass stopcock . . 2839T Stand for carrying the absorption apparatus, consisting of tripod foot with lacquered iron rod, 12 by f, with 8 clamps 28401 Ditto, with 4 clamps 2841 284 1T Apparatus for regulating the admission of oxygen £086 2842 2842T Improved Form of Apparatus for regulating the admission of oxygen, fitted with three stopcocks . . . . . . . . . . . . . . £0106 CROSS STREET • HATTON GARDETST, E-C 548 BAIRD &TATLOCK (LONDON) LTD. 2843 • 0 2843T Improved Form of Apparatus for regulating the admission of oxygen. Complete with two drying cylinders as figured . . . . . . . . . . . . , . . £0 13 6 2844T Combustion Tubes of Jena Glass, 86 centimetres long by 16-18 millimetres internal diameter, open both ends . . . . . . . . . . . . each £013 2845T Combustion Tubes of Jena Glass, 30 centimetres long by 16-18 millimetres internal diameter, closed at one end . . . . . . . . . . . . each £012 2846 2846T Inner Tubes of Jena Glass, 14 millimetres diameter, open both ends, as figured. Length . . . . . . . . 15 18 21 cm. Price . . . . . . . . 8d. 9d. lOd. each. 2847 2850 5847T Inner Tubes of Jena Glass, 14 millimetres "diameter, with one end closed and fitted with hook Length Price !848* Troughs of Porous Porcelain Length Price ii 4d. ii 5d. 13 5d. 13 6d. 17 cm. 6d. each. 17 cm. 7d. each. !849T Combustion Boat of Meissen porcelain, 75 by 9 millimetres !850? Combustion Boat, with three divisions '85 1T Combustion Boat, porous, with three divisions !852T Combustion Boat, of Berlin porcelain, 14 centimetres long, with round bottom for lead peroxide •853T Combustion Boat of stout copper for nitrogen determinations £005 £0 1 2 £0 1 3 £0 1 3 £023 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 549 BAIRD &TATLOCK (LONDON) LTD. 2854-2855 2856 2854T Weighing Bottles, with foot and ground-in stopper . . . . each 2855* Weighing Bottles, larger size, to take combustion boats 14 centimetres long . . 2856T Wash Bottle for Palladium Chloride, with ground-in stopper £009 £0 1 0 £0 1 6 2858 2860 2857* Schiffs' Nitrometer, ordinary pattern 28581 Schiffs' Nitrometer, modified by Prof. Dennstedt 2859* Safety Valve, Bunsen's, for use with nitrometer 28601 Drying Tower, Dennstedt's, with ground-in tube with stopcock, rubber stopper, and tube £090 with stopcock 286 11 Drying Tower, as above, but with ground-in stopper at top and porcelain perforated disc £010 0 28621 Aspirator Bottle, 3 litre capacity, with tubulure . . . . . . . . . . £036 28631' Double Forked Tube Glass, for use with the double furnace, No. 2826 . . . . £004 2864? Table Support, brass pillar and base with polished wood table igf centimetres diameter £056 2865T Tongs for removing the iron covers . . . . . . . . . . ..£010 CROSS STREET • HATTQTST GARDETST, E-C 550 BAIRD &TATLOCK (LOM)ON) LTD. 2866 2866T Furnace, Combustion, consisting of a light wrought iron frame work onwhich is supported a central long tube burner, and each side there are two spreader burners, all of which are removable and adjustable. The upper portion containing combustion tube, is covered by angular wrought iron covers, with mica windows. The length overall is approximately 3 feet. Complete with iron stand and cross bar, with copper hooks for supporting glass vessels attached to combustion tube £2 15 6 2868 The engraving shows the furnace open ready for the introduction of a tube. Furnaces for Heating Tubes, No. i pattern. This will heat an iron tube of | to I in. diameter to its softening point in ten minutes, using a small foot blower ; I or it will heat the same tube to redness without a blast, the same burner being applicable for either draught or blast. To use a draught furnace, connect the tap (A) with the gas supply, closing both the other taps. As a blast furnace, connect (B) to a second gas supply full J-in. bore and connect (c) to a foot blower. When the blast is applied the tap (A) must be closed and the gas supplied only from (B). In the pattern with adjustable length of flame, at the side of (A) is a screw plug which adjusts the area of the gas jet without affecting the pressure of gas. The gas supply when used without a foot blower must be adjusted by this plug only and not with the tap, which must be full on. This plug adjusts the gas supply for varying lengths of flame, the length of the flame being altered by a sliding plug in the tube. On the end of the rod carrying the sliding plug is a tap which can be con- nected to an air supply for the purpose of cooling the part of the tube not exposed to the flame, preventing the heat spreading too rapidly by conduction. The above can be used with air gas or coal gas. 12 18 24 in. 2868 For draught or blast, with adjustable flame length . . 40/- 42/- 50/- 2869 As above, without adjustable length of flame . . 35/- 37/6 40/- 2870 With fixed length of flame, without blast . . . . 25/- 30/- 34/- 2871 Extra fireclay blocks, 6 in. long The foot blower No. 3, Fig. 2025, is the best for this furnace. each £0 1 2 BAIRD &TATLOCK (LONDON) LTD. 2872 2872 Furnace for Heating Tubes, No. 2 pattern. The furnace body is in 6-in. sections, and can be made up to any length without any obstruction, such as occurs when a long Hoffmann furnace is used with a short tube. It will take tubes I in. external diameter. The burners can be made any length, and any part of them used. The blocks and covers are sold separately, and the burners can be supplied in sections of 6, 12, 18, 24 and 36 in., so that any number can be used in a line without a break, enabling the furnace to be at once built up to any length required. Length Price 12 £280 18 £3 12 0 24 £4 16 0 36 in. £740 2873 2874 2875 2876 2877 2873 Furnace Tiles, finest fireclay, for Bunsen's furnace for furnaces, Fig. 2821 per doz. 2874 2875 2876 „ 2877 2878 2879 Furnace Gutters, sheet iron. Length Price Hoffmann's furnace, side top . . Erlenmeyer's furnace Glaser's furnace, top side 2818 2818 2817 2819 2819 £0 £0 £0 £0 £0 £0 18 I/- 28 1/4 32 in. 1/6 each. 2880 Furnace Gutters of pure nickel , 25 millimetres wide and about i millimetre thick. Length . . . . .... . . 20 60 80 90 cm. Price .. .. .'. .. 1/3 3/6 4/6 5/6 each. CROSS STREET • HATTON GARDE1ST, E-C 552 BAIRD &TATLOCK (LOTSIDON) LTD. I 2881 2882 2883-2884 . . per doz. 2881 Clay Troughs for tubes 7 by i in. .. .. .. per doz. £056 2882" Fireclay Trough, double, with fireclay moulds fitted inside for melting small quantities of easily fusible metals, etc., on stand . . . . . . . . . . each £039 Extra moulds, per doz. 2/3 2883 Clay Burners for Hoffmann's furnace, large 2884 Clay Burners for Hoffmann's furnace, small for furnaces Fig. 2818 per doz. £033 2818 £033 2885 2885s Furnace, for sealed tube operations, as used by Lothar Meyer, with strong sheet iron insulated cover and inner tubes, 2-tube Bunsen burners, as illustrated. For . . . . . . . . . . 4 8 tubes. Price complete . . . . . . 85/- 105/- For Assay Furnaces for use with coke, wood, and petroleum, see Assay Section at end of Catalogue. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD ^T^TLOCK. (LONDON) LTD. 2888-2889 2886s Furnace, Hempel's, small draught for crucibles, consisting of tripod with metal chimney, inside of which is the fireclay cylinder with cover. Price with Bunsen 2887 Extra clay parts and covers, best English fireclay . . per set F. R. & Co.'s Compressed Oxygen Injector Furnace. For the rapid fusion of metals and the treatment of refractory substances at all temperatures. This furnace is entirely self-acting. A very fine jet of compressed oxygen is first mixed with air, then with coal gas, the pressure of the oxygen being utilised to make this mixture and blow it into the furnace chamber at a high speed. The quantity of oxygen used depends on the temperature and speed of working required, but under any circumstances is very small for the work done ; and owing to the very large proportion of air used with the oxygen, there is no tendency to local heating or perforation of the crucible. The temperature is under the most perfect control from a red-heat to the almost instantaneous fusion of the most refractory crucibles. The heat is perfectly steady without any attention ; one oxygen cylinder 2 ft. long and 6 in. diameter will work the furnace for several hours without any attendance whatever. The furnace casings are the ordinary well-known injector pattern, but are lined with a special refractory material to resist the very high temperatures, which are obtained with the greatest ease. The burner is of the simplest possible construction, and is not liable to damage or to get out of order. We cannot guarantee any casing against fusion if the furnace is worked at its maximum power. The price of extra furnace bodies is 6/- ; extra lids, 2/6. PRICES. 2888 Furnace and burner to take Morgan's No. oo crucibles, capacity £ Ib. iron 2889 No. i alb. £0 17 6 £0 19 0 CROSS STREET • HATTOTST GARDETST, E-C 554 BAIRD &TATLOCK (LONDON) LTD. 2890 Perfected Injector Furnace, for metallurgists, jewellers, chemists, manuiacturers of arti- ficial gems, and other purposes. Works equally well with coal gas or air gas. POWER AND SPEED OF WORKING. With J-in. gas pipe and the smallest foot blower, the smallest furnace will melt a crucible full of cast-iron scrap 7 minutes, tool steel in 12 minutes, and nickel in 22 minutes, starting with all cold. With a foot blower No. No. 2025, cast-iron can be melted in any furnace up to 12-lbs. size, tool steel or nickel in any up to the 6-lb. size ; essemer or gun steel in the smallest size. For higher powers or large furnaces a Roots' No. 2033 or Lennox No. o2g blower, driven by power, is necessary, and the air jet must be enlarged to about double the size which can used with a foot-blower. To take Crucibles No. 00 i 3 6 M 2890 Price of furnace .. 9/6 11/6 19/- 27/6 451- Size of crucibles in inches outside measure 2j by 2 3 by 2| 4i by 3j 6 by 4 8 by 6J Capacity in Ibs. iron 3 2 6 12 28 2891 Foot blower (No. 3) 291- (No. 3) 291- (No. 5) 33/6 (No. 5) 33/6 2892 Indiarubber tubing 3f- »/- 3/9 3/9 — 2893 Price complete ready for use with blower & tubing 431- 45/- 59/3 67/9 — 2894 Extra furnace bodies 31- 4/8 8/- I3/- 20/- 2895 Extra furnace lids 2f- 2/3 3/9 6/6 10/- 2896 Crucible tongs 11- I/- 1/6 1/6 2897 Bow tongs 3/- 4/- — 2898 Crucibles, fireclay l£d. 2d. 5d. lOd. 2/4 2899 „ " Salamander " . . 4|d. 5£d. 1/5 2/10 5/8 For the fusion of pure nickel over 6 Ibs. at once a small power blower is necessary, and the air jets of the burners must be enlarged to double the size. The air supply of the 28-lb. size must be controlled if necessary J3y a valve or large tap. Gas supply required 6 oz. size furnace f in. pipe = 7 to 2 Ib. „ f ,, = loto 61b. „ } „ = 25 to 12 Ib. „ § „ = 30 to 28 Ib. „ i „ 30 ft. of gas per hour. 40 ft. „ 60 ft. „ 70 ft. „ „ ij ,, = ioo to 300 ft. „ All internally fired casings crack the first time they are used, but should not alter afterwards. BAIRD &TATLOCK (LONDON) LTD. 2900-2903 Reverberatory Gas Furnaces, for crucibles, muffles, cupels, etc. Floor Space in Furnace. No. Long. Wide. High. Crucibles and Ci 2900 i H 14 in. 4 in. 4 in. 70/- i 2901 23 H 10 „ 5 ,- 5 ,- 70/- 2902 33 H 14 .- 5 ,, 5 ,- 80/- 2903 6 H 14 „ 6 „ 1\ „ 90/- Price of Furnace with draught Burner for els. Muffle doors and stoppers, 8/- each. Burner and plug for blast arrangement, 10/6 extra. i H will take five 2-lb. crucibles at once, or two muffles about 4 in. wide by 4! in. long by 2j in. hig 23 H will take two 6-lb. crucibles, or two muffles 3 by 5j by 3j in. 33 H „ three 6-lb. ,, ,, 4i by 5j by 3f in. 6H „ two i2-lb. ,, ,, 4 by 7 by 4^ in. 6 H requires a special burner when used for muffles or cupels, all the others work with the same burner for both purposes. The price of burner is 14/- extra. In ordering muffles, say if with perforations for oxidising, or plain for enamels and similar work. tier Clay. 1/3 1/2 Salamander. 2/6 2/3 Muffle for i H . . 23 H . . Muffle Furnaces for use with petroleum, see Assay Section at end of Catalogue. Muffle for 33 H 6H Clay. 1/3 1/6 Salamander. 2/6 CROSS STREET • HATTO>T GARDETST, E-C 556 BAIRD &TXTLOCK (LONDON) LTD. 2904 2904T Carr's Patent Crucible Furnace, two fires in one frame, specially designed for use in Technical Schools, adapted to take Battersea assay crucibles, complete with solid firebrick linings and flue pieces, as shown, but with bottom ash guards as " D " only . . . . £10 12 0 2905T Extra for two top ash guards as at C . . . . . . . . . . £0 10 0 2906T Spare Solid Linings with flue pieces . . each, 10/6 ; for the two linings £110 2907T Spare Firebars .... per set, 10/- ; for the two sets £100 2908T Carr's Specially Designed Dampers, as shown, to give a flue passage of 9 by 9 in. when fully open . . . . . . . . . . each, 7/6 ; for the two flues £015 0 2909-2911 2909s Meker Crucible Furnace, Type E, for extra high temperatures up to 1800° to 1850° C. (3272-3360° F.), adapted for compressed air. In this furnace the crucible (c), of special refractory clay, is mounted on a crucible support (B). This stands on a fireclay ring (A), which also supports a cylinder (D). The flame from the burner rises up through the hole in the ring (A) past the crucible and is then turned downwards between the outer wall of the cylinder (D) and the inside of the furnace body. In the illustration a part of the cylinder (D) shown cut away in order to show the crucible. 2910s Size No. 2 E. Diameter of crucible 35 millimetres by height 60 millimetres . . . £10 2 0 Extra crucibles with lids, 1/9 2911s Size No. 5 E. Diameter of crucible 66 millimetres by height 120 millimetres .. .. £17 7 0 Extra crucibles with lids, 6/9 For Foot Bellows and Air Pump see respective numbers in Catalogue. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. 2912 2914 2912s Meker Crucible Furnace, Type C, for use with compressed air, for temperatures up to 1600° and 1700° -C. = (2912° and 3092° F.) The illustration shows the general appearance of the " Type C " Meker furnace, with the crucible " B " and the fireclay block " A," on which the crucible stands. This fireclay block is made of a very refractory clay, and is shaped with a trough round its upper surface, so that if the crucible should break, the metal is collected in this trough. The furnace lid is mounted on a carriage, which can be easily rolled to one side on guide rails. Fireclay crucibles cannot be made to stand at the extremely high temperatures which can be obtained in this type of furnace. We therefore supply plumbago crucibles usually, although if requested, we can supply fireclay crucibles which will be quite satisfactory up to about 1500° C. (2732° F.) A good pressure of air, say 10 or 15 Ibs. per square inch (0.7 to i.o kilograms per square cm.), is necessary to obtain the very high temperatures. Size of crucible 100 mm. to 120 mm. high. Price complete 2913s Extra fireclay crucibles, lOd. each ; extra plumbago crucibles, I/- each. Meker Tube Furnace, Type S, requiring compressed air for temperatures up to 155° to 1650° C. = 2822-3002° F. Fig. 2914 illustrates the type " S " furnace, and shows a spare tube lying in front. It will be seen that the flame comes in at the side, and therefore rotates around the tube like a screw thread from one end to the other, escaping in a vertical direction. With this furnace a temperature of 1500° C. can be obtained in 15 minutes, if a good air pressure is available. Our stock furnaces are usually closed at the end of the tube opposite the door, but we can supply them with the tube open at both ends if specially requested to. 2914s Size No. 4 S. Internal dimension of tube 40 millimetres diameter by 165 millimetres long Price spare tubes, 4/9 2915s Size No. 5 S. Internal dimension of tube 65 millimetres diameter by 230 millimetres long Price spare tubes, 5/9 2916s Size No. 6 S. Internal dimension of tube 120 millimetres diameter by 320 millimetres long 2917s Special Tube Furnace, Type T, not requiring an air blast. Price complete with burner We can supply to order special tube furnace in which the tube is heated by ten ordinary No. 4 Meker burners, and therefore no air blast is required. The temperature limit with this type of furnace is about 1200° C. Internal diameter of tube 5 cm., length 39 cm. Muffle Furnace, Type D (requiring compressed air). Although furnaces of this type are not illustrated we can supply them to order. The temperature attainable is from 1550° to 1650° C. with I kilogram per square centimetre (15 Ibs. per square inch) air pressure. £660 £8 13 0 £26 5 0 £12 17 0 2918s Size No. 2 D. 2919s Size No. 40. Muffle dimensions 40 by 20 by 60 millimetres 65 by 40 by 100 £330 £4 14 6 • CROSS STRET • HATTOTST GARDETST, E-C BAIRD &.TATLOCK (LONDON) LTD. 2920-2922 Meker Crucible Furnace, Type ], without air blast. 2923-2925 This type of furnace is very useful for a large number of purposes since in it temperatures of from 1050° C. to 1100° C. can easily be obtained without the use of an air blast. The crucible, which is fitted with a lid, is supported I at three points only and the flame therefore completely envelops it. The No. 4 J furnace uses an ordinary No. 4 ! burner, and the No. 5 ] a. No. 5 burner. A special durable fireclay crucible is included with each furnace. We can supply at a slight extra cost, crucibles of Berlin porcelain. For obtaining the highest temperatures quickly these are useful, being thinner than the fireclay crucibles. 2920s Size No. 4 J. Diameter at top 35 millimetres, height 35 millimetres 2921s Size No. 5 J. „ „ 50 „ „ 55 80 ,,85 29225 Size No. 7 J. Extra crucible with lid for use with above. Size 4 Price 4d. 5 6d. 7 8d. each. Meker Muffle Furnace, Type M, for incineration, cupellation, ceramic and enamelling work, annealing steel, etc. Temperature limit, 1050-1100° C., 1922-2012° F. 2923s Size No. 4 M. Width 115 millimetres, height 70 millimetres, length of muffle 170 millimetres, gas consumption per hour, 42 cubic feet 2924s Size No. 6 M. Width 145 millimetres, height 100 millimetres, length of muffle 230 millimetres, gas consumption per hour 63 cubic feet 2925s Size No. 14 M. Width 320 millimetres, height 190 millimetres, length of muffle 550 milli- metres, gas consumption per hour 147 cubic feet £160 £2 10 0 £440 £3 15 0 £550 £26 5 0 .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 559 BAIRD &TATLOCK (LONDON) LTD. 2926-2930 Double Muffle Furnaces (draught), for assaying, hardening, case-hardening, tempering, etc. This arrangement of double muffle furnaces is heated by only one set of burners, which, without loss of heat in the bottom muffle, or increased consumption of gas, will maintain in the top muffle a temperature of approxi- mately 300° F. below that of the bottom one. The body is erected with strong cast-iron casing, lined inside with non-conducting material, inside which the fireclay body of the furnace is built. All parts of the furnace are easily detachable. These furnaces are specially suited for hard daily use where absolute precision and reliability are required, though where it is necessary to maintain exact temperatures for long periods, the use of a good gas pressure governor with one of our dial-indicator gas taps (designed specially for fine adjustments of gas supply) is recommended. See Nos. 2931-2937. Lifting counterbalanced door, or loose stoppers, supplied in place of hinged doors, if ordered. Two fireclay muffles, four fireclay trays, or one muffle and two trays supplied with each furnace. Cast-iron muffles can be supplied to all sizes, silica muffles for Nos. 2926 to 2929 only. With all classes of work in which it is not absolutely necessary to protect the contents of the furnace from the products of combustion, a considerable saving in gas consumption can be effected by substituting a tray in place of the muffle, thereby forming what is commonly known as an oven furnace. For most classes of work for which the oven furnace is suitable, a saving of 25% in gas consumption is effected by this means, and also the cost in renewals of trays is considerably less than that of muffles. Clear Working Space Clear Working Space inside Muffle in inside Muffle in Size of Gas Consumption Furnace No. inches. millimetres. Gas Supply per hour. Price. Width Height Depth. Width Height Depth. Pipe. ins. ins. ins. mm. mm. mm. 2926 6 X 4|X 10 153 x 115 x 254 f-in. 60 cub. ft. £15 17 6 2927 8 x 6 x 14 204 x 153 x 356 f-in. IOO „ £22 0 0 2928 10 x 6 X 14 254 x 153 x 356 i-in. 110 £25 15 0 2929 12 X 6 X 14 305 x 153 x 356 i-in. 180 £29 12 6 2930 14 X 6 X 18 356 x 153 x 457 i-in. 22O ,, £39 10 0 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &.X\TLOCK (LONDON) LTD. 2931-2937 A2937 Dial Indicator Taps for use with all-draught furnace. These taps are made throughout in brass, have a full bore in the plug and barrel, and are fitted with screw on ; they are strongly recommended for use in connection with a gas governor, where exact regulation of emperature is absolutely necessary to successful results being obtained with the furnace. The brass dial is calibrated so as to enable the operator, by taking note of the gas pressure and position of the nter on the dial, to practically repeat at will any required method of firing the furnace. 1 Size of tap, iron threads J-in. !932 „ „ ., |-in 1933 „ .. |-in. :934 „ „ x-in ;935 ,, ., ,, ij-in. ;936 „ „ ii-in. 937 2-in 2937 Muffle Furnace (draught), for assaying, :namelling, etc. This furnace is the most economical and practical draught muffle furnace ever placed on the market. It is instructed with firebrick body, surrounded with non-conducting material, and fitted into a strong cast-iron ising, the finest material and workmanship obtainable being used in its manufacture, while the finish and appear- mce will allow of its being placed in the best-appointed studios. Each furnace is fitted with muffle of pure fused silica. Price with silica muffle . . . . £6 Clear working space inside muffle, width 4-in., height 3-in., depth y-in. (102 x 77 x 178 mm.) £083 £089 £0 10 9 £0 15 0 £150 £1 13 6 £300 5 0 2938-2942 Muffle Furnaces (draught), for hardening, case-hardening, tempering, assaying, etc. The construction of these furnaces is carried out on the latest scientific principles ; the finest quality material and workmanship only are employed. The body is erected with strong cast-iron casing, lined inside with non-conducting material, inside which the fireclay body of the furnace is'built. All parts of the furnace are easily detachable. These furnaces are specially suited for hard daily use where absolute precision and reliability are required, though where it is necessary to maintain exact temperatures for long periods, the use of a good gas pressure governor with one of our dial-indicator gas taps (designed specially for fine adjustments of gas supply) is recommended. (See Fig. 2931-2937.) Lifting counterbalanced door, or loose stoppers, supplied in place of hinged doors, if ordered. One fireclay muffle or two fireclay trays supplied with each furnace. Cast-iron muffles can be supplied to all sizes, silica muffles for Nos. 2938 to 2941 only. With all classes of work in which it is not absolutely necessary to protect the contents of the furnace from the products of combustion, a considerable saving in gas consumption can be effected by substituting a tray in place of the muffle, thereby forming what is commonly known as an oven furnace. For most classes of work for which the oven furnace is suitable, a saving of 25% in gas consumption is effected by this means, and also the cost in renewals of trays is considerably less than that of muffles. Clear Working Space Clear Working Space inside Muffle in inside Muffle in Size of Gas Con- inches. millimetres. Gas Supply sumption Price. Width Height Depth. Width Height Depth. , Pipe. per hour. 2938 ins. ins. ins. 6 X 4* X 10 mm. mm. mm. 153 x 115 x 254 f-in. 60 cub. ft. £950 2939 8 X 6 X 14 204 x 153 x 356 f-in. IOO „ £12 0 0 2940 10 x 6 x 14 254 x 153 x 356 i-in. 110 „ £14 5 0 2941 12 x 6 x 14 305 x 153 x 356 i-m. 180 „ £16 50 2942 14 X 6 x 18 356 x 153 X 457 i-m. 220 £21 15 0 CROSS STREET • HATTCTK GARDETST, E-C 562 ml' BAIRD ^lATLOCK (LONDON) LTD. 2944-2947 New Series of Concentric Jet Furnaces for Petroleum Oil. The same furnaces designed for gas can now be supplied with burners using ordinary petroleum • paraffin oil with equally perfect results. Starting all cold, the largest, No. 6 size, crucible, full '. cast-iron scrap, can be melted in less than twenty minutes. One gallon of petroleum will work largest size at full power for two hours. A clear dazzling white heat is easily obtained when aired. These furnaces require less blowing than the gas furnaces of the same pattern, the smallest, [>. 3 size blower, being amply powerful for all sizes up to No. 6. 2945 2946 2947 Furnace No. oo. „ i. „ 3. „ 6. Taking crucibles 2\ in. high by 2 in. wide 3 „ 2f ,. 4t .. ' 31 » 6 4l „ £220 £276 £2 15 0 £3 5 0 Foot Blowers extra. See Fig. 2025, Indiarubber Tubing extra. 563 20 BAIR-D &TATLOCK (LONDON) LTD. * ~*wi >" • • 2948 2948 New Pattern " Universal " Furnace. A new and simplified pattern of the well-known " Injector " Furnace, with the advantages of the " Concentric Jet " pattern. For all high temperature work up to the melting point of tool steel and nickel. The burner is made without gauze, and the position of the same being stationary, absolute precision in working is obtained, the gas and air supplies only require regulating. No. oo size, taking crucible 2j by 2 in., capacity J Ib. . . Extra crucibles, fireclay, l£d. ; " Salamander," 4£d. each. 2949 Draught Crucible Furnaces, for coal gas or air gas. For brass casting, jewellers, and general purposes. Not suitable for cast-iron. 2949 Furnace No. 163, taking crucibles not exceeding 3 by 2§ in. to melt 2 Ibs. brass, price complete . . . . . . . . . . . . . . ' . . £110 (For prices of accessories see page 565.) CROSS STREET - HATTCnST GARDETST E-C 564 BAIRD &TATLOCK (LOM)ON) LTD. 50 Extra crucibles — salamander . . . . . . each £006 51 „ clay .. .. .. ,,£002 52 Extra grids for burners £020 53 Extra gauzes . . . . . . . . . . . . . . £006 Gas supply required, 40 cubic ft. per hour == i in. pipe and tap. .54 Furnace No. 363, taking crucibles not exceeding 4 by 3.^ in. to melt 6 Ibs. brass, price complete . . . . . . . . . . . . ..£250 Extra crucibles — salamander . . each £015 ^56 „ clay . . . . . . ,,£005 1 57 Extra grids for burners . . £020 ; 58 Extra gauzes . . . . . . . . . . . . . . £006 Gas supply, 60 cubic ft. per hour = J in. clear bore gas pipe and tap. The lid never requires to be lifted, it can be pushed sideways sufficiently to enable crucibles to be lifted out. 2959 59 Lecture and Experimental Furnace Working with the same burner as a draught or blast furnace at any temperature up to the fusion ice casing, and adapted for crucibles, muffles, tubes, cupels, distillation by descension, treatment of substances with gases, at high temperatures, small forgings, roasting ores, etc. :. — When used as a blast furnace, ar, empty crucible 2V by 2j in. can be raised to the fusing point of •von in two minutes, starting all cold. When the plug is removed and replaced by the chimney, the blower being stopped, it will raise tha ible to bright redness in about ten minutes. This requires the gas to be turned very low, and the adjustment • is a draught furnace requires some little practice to obtain the best results. If the gas is in excess inns at the top of the chimney instead of in the furnace, and, of course, does no work. The best results are •'.c0 Extra muffles, fireclay 2.1 2'. 2 M.3 crucibles muffles, salamander crucibles, £1 17 6 £009 £002 £0 1 6 £004 565 BAIRD &TATLOCK: (LONDON) LTD. Furnace with draught arrangement, external view. 2964 (Fig. i) 2964 Muffle Furnace with Burner. No. Space inside muffle Price, for draught only Extra muffles, clay „ salamander Extra grids for burners „ gauzes 2965 2966 2967 2968 Furnace with draught burner, showing internal arrangerr 2964 (Fig. 2) 261 461 661 2 by 2 by 4 3% by 3 by 6J 5f by 4* by 9 in. 40/- 45/- 80/- 9d. 1/6 2/6 each. 1/6 3/- 5/- „ 21- 2f- 2\- „ lOd. lOd. lOd. INSTRUCTIONS FOR MUFFLE FURNACES, Nos. 261, 461, and 661. The gas supply tap and pipe must be large and clear, so as to give as great a pressure of gas as possible at the burner nozzle, although the actual consumption of gas is small. The indiarubber tubing used must of necessity be perfectly smooth inside. The tubing made of wire, whether the wire is removed or not, will not work these burners satisfactorily. All muffle furnaces are sent out with a 2 ft. 6 in. chimnej7, having a cast-iron foot to enable it to stand steadily, and a short handle by which it can be readily lifted with the crucible tongs. The gas supply specified is required to work each furnace at its full power, and the flame must be visible in the chimney. If the gas supply is deficient, the furnaces can be worked at a lower heat by partially closing the top of the chimney until the flame becomes visible, or by working without chimney. If the burner plate becomes red-hot, it is a sign that the gas supply is deficient. The points of blue flame are always visible when the burner is looked into sideways, unless the gas supply is too small to work the furnace satisfactorily. To light the burner without removing the upper part of the furnace, put a lighted taper through the burner casing up between the grooves in burner plate, then turn the gas on, slowly. If the furnace is hot it may be necessary to cover the air opening round the gas entrance to prevent the flame descending through the gauze at the moment of lighting. The burners can be easily taken apart, and must be kept clean. See also Assay Section at end of Catalogue. CROSS STREET • HATTCTK GARDEN, E-C 566 BAIRD &TATLOCK (LONDON) LTD. 2969-2971 New Perfected Muffle Furnaces, for petroleum oil or coal gas. This pattern takes a No. 4 muffle, the inside dimensions of which are 3$ in. wide, 6| in. deep, i. high, and is of the size specified by the Board of Education for School and College use. Type A. — Shows it as adapted for petroleum and air blast. Where air under pressure is not available, a No. 3 foot blower is ample to work it at full power. The price as illustrated with oil tank and burner, but without blower, is yQ Type B.— Fitted with new automatic petroleum burner, for use where no blast is obtainable. Price, complete with all fittings, as illustrated . . rl Type C. — Fitted with gas burner for use with foot or power blower, price . . The temperature obtainable is well over 2,ooo? F., the heat is under perfect control and even Jughout the muffle. May be used for hardening, enamelling glass and pottery painting, assaying, etc., etc., with tect success. £500 £9 5 £4 0 0 0 jCHEMICAI/AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 567 BAIRD &.TATLOCK (LONDON) LTD. 2972 Electric Cupel Crucible Furnace, for the laboratory, with directing magnet.* transactions of the Academy of Sciences, No. 12, 2oth March, 1893. Ihis furnace is intended for laboratory experiments and tests. The first type brought out in 1892 was with vertical carbon pencil ; it is based on the Siemens' electric furnace. The present type has oblique carbon pencils, movable in metallic mounts (G G). It is easy to bring them into contact or withdraw them from each other. As in the first type, the whole forms a closed vaulted chamber with fireproof linings (R), receiving the movable crucible (CR). Channels serve for the circulation of gases or the introduction of materials to be submitted to the action of the electric arc. The phenomena of fusion and reduction may be observed direct, the sides of the apparatus having movable covers (or doors) fitted with mica panels. They may be produced with zirconium and thorium, as has been demon- strated by Mr. Troost in carrying out his experiments with this apparatus (Transactions of the Academy o/ Sciences, 2gth May, 1893). The movable crucible (CR) can be shifted from outside at the will of the operator, the base-plate on which it rests being manipulated by means of the rod (RE) . This crucible is of carbon, graphite, magnesia, limestone, lime, or metal according to the material to be reduced. The arc playing between the carbon pencils (C C) may be transformed, at a distance, into an elongated flame forming a veritable electric blowpipe flame, thanks to the directing action of a magnet (Ai) , placed near the apparatus. Thus the arc can be withdrawn, if necessary, at will, or directed upon the material contained in the crucible (CR). This arrangement, devised by us, is a novel application of a known phenomenon already utilised by Jamin in his electrical lamp. Thus the material contained in the crucible is gradually brought to the maximum temperature. (The wooden block supporting the magnet may be dispensed with ; it will suffice to give an inclined position to the magnet while letting it rest direct on the table and the slate base of the apparatus.) The small laboratory type, with a current of from 12 to 30 amperes and 55 to 70 volts in the terminals, permits obtaining the reduction of oxides and the fusion of the most refractory metals in sufficient quantities for spectral or chemical analysis. All experiments and laboratory tests demanding a very elevated temperature can be realised with this apparatus. The large type will bear currents of greater intensity ; the pencils (C C) are in this case provided with mountings permitting circulation of water around them. NOTE. — Do not touch the conductors carrying the electric current to the binding-screws of the crucible, except by taking hold of them in insulated parts ; the currents employed, whether continuous or alternating, may be dangerous to bear. It is useful, moreover, to insert in the circuit near the apparatus a " high-intensity current " switch. To avoid the action of the intense rays of the electric arc upon the eyes or the skin, it is indispensable to protect oneself with special spectacles and screens. PRICES. 2972T Electric crucible No. i, Small type as per above figure. For crucibles (Cr), in the form of a cupel, from 33 to 35 millimetres outside diameter. Movable base-plate with clamp screw. Slate base on four cast-iron legs. With one carbon crucible (Cr) and one crucible of limestone, Nos. 3 and 5, without directing magnet . . (This crucible No. i is for currents from 12 to 30 amperes, 50 to 70 volts ; carbon pencils 10 millimetres in diameter.) Prices continued on page 569. CROSS STREET • HATTOTST GARDETST, E-C 568 e^sr*- BAIRD &L TATLOCK (LONDON) LTD '^xr^ ( ^— ' 133 ft ^ )73T Directing magnet (Ai), No. i triple horse-shoe £1 7 6 )74T Cupel crucible (Cr), 33 to 35 millimetres outside measurement, of carbon . . each £0 1 0 )75* graphite £0 2 0 976- limestone £0 1 0 97?T magnesia . . £0 2 0 978T Carbon pencils, 10 millimetres diameter . . . . per metre £0 1 0 979T Spare mica panels, for cover or door K . . . . . . . . each £0 0 9 9801 Electric crucible No. 2 of larger dimensions. The carbon pencils (C CJ have mountings permitting circulation of water around them. This type is for currents from 50 to 100 amperes, 50 to 70 volts ; the carbon pencils are 20 millimetres in diameter. The cupel crucible (Cr) is 60 millimetres outside diameter by 34 millimetres external height. With one crucible No. n and one No. 13 ; without directing magnet No. 2 £8 5 0 981T Directing magnet No. 2, fivefold compound horse-shoe £2 15 0 982T Cupel crucible (Cr), 60 millimetres, of carbon . . . . . . . . each £0 1 6 983* ,, ,, ,, graphite . . . . . . . . ,, £0 3 6 984T limestone . . £0 2 0 985T ,, „ magnesia £0 3 6 986T Carbon pencils, 20 millimetres in diameter . . . . . . per metre £0 3 0 9871 Crucible tongs of iron, with curved ends . . . . . . . . each £0 3 0 9881 Safety spectacles, new model, entirely preserving the sight, movable tinted glasses £0 4 6 989T Hand screen, of glass, 18 by 24 centimetres, consisting of two superposed coloured glasses, giving a neutral tint £0 2 6 990T Circuit-breaking switches, forming " two direction " (reversing) switches, for powerful •^ currents of 50 to 100 amperes . . . . . . . . . . £1 to £3 10 0 991x Rectangular bricks, of dense refractory magnesia ; they serve for building, on the spot, electric crucibles of larger dimensions than No. 2, for industrial experiments each £0 2 o 'CHEMICAL AND SCIENTIFIC APPARAWS AND PURE CHEMICALS. 569 BAIRD &IATLOCK: (LONDON) LTD. ELECTRIC TUBE AND CRUCIBLE FURNACES. For experimental work these furnaces are very suitable, as complete control of the temperature may be obtained by means of an external resistance. They are arranged so that very little heat is lost, and they are therefore economical and easily handled. A very high temperature may be obtained without the inconvenience of excessive radiant heat or objectionable fumes which may damage the couple wires and sometimes the material under treatment. The furnace consists of a porcelain tube round which a thin strip of platinum foil is wound. This is protected by a heavy lagging of fireclay and asbestos. Please state voltage and current when ordering. 2992-2995 2996-2997 Horizontal Tube Furnace, Type A, 20 millimetres diameter of tube, highest temperature about 1400° C., reached in about 20 minutes. Nos. I 3 4 Length of tube 60 44 22 centimetres Mean consumption of current at no volts Amps. 22 16 10 220 volts Amps, ii 81 Not made. 2992* Price . . 95 j- 90/- 75/- 2993r Platinum extra at 8/- per gramme. Price variable. Add 9 7 4 grammes. 29941 Resistance for no volts current extra 120/- 70/- 50/- 2995' „ 220 volts current extra 105/- 65/- - Horizontal Tube Furnace, Type C, diameter of tube 40 millimetres, highest temperature reached 1,350° C. in about 20 minutes. Nos. i 3 Length of tube . . 60 30 centimetres 2996' 2997* 2998T Mean consumption of current at no volts „ 220 volts Price Resistance for no volts current 220 volts current • • Amps. 30 Amps. 15 120/- extra 215/- extra 190/- 20 xo 95/- 120/- 102/- 2999r ,*^S Platinum extra at 8/- per gramme, price variable. Add . . 15 9 grammes. rfE»v jiff 14 • CROSS STREET • HATTOTST GARDEN, E-jCyJT 570 BAIRD &.TATLOCK (LONDON) LTD. 3000-3002 3000T Crucible Furnace, with stand, adapted for temperatures of i,ioo°C. This furnace will take a crucible of about 35 cubic centimetres capacity, with small porcelain triangle, wire, and wall plug adapted for no volts with 7.5 grammes platinum (at 8/- per gramme) 300 1T Crucible Furnace as above with non-regulating resistance with 7 grammes platinum (at 8/- per gramme) 3002r Regulating resistance for No. 3,000 or 3,001 for varying the temperatures between 700 and 1100° C., extra £580 £690 £250 3003T 3004' 3005r 3006T 3007r 3008T 3009' 3003 Electric Crucible Furnace, No. i, with carbon regulator for 150 amps., 50-60 volts. This furnace is fitted with movable carbon regulator, and will take crucibles no milli- metres high by 95 millimetres diameter, capacity 300 cubic centimetres. Price without cables . . . . . . . . . . . . . . . . ..£88 I pair of cables for use with above, 150 centimetres long with connecting terminals . . £27 Cable per metre extra per pair . . . . . . . . £015 Graphite crucibles no by 95 mm. . . . . . . each £0 0 Carbon plate, lower electrode . . . . ..,,£02 Carbon electrode 750 by 30 mm. . . . . . . ,, £0 1 • Fireclay bottom plate . . . . ..,,£01 Fireclay body without iron bands . . . . . . . . . . , £010 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- RAIRD &.TATLOCK (LONDON) LTD. 3010 3010T Carbon Tube Furnace. Electric resistance furnace (carbon tube type). These furnaces are made with carbon tubes from 1.5 centimetres bore by 30 centimetres long, up to 3 in. bore by 18 in. long, for temperatures up to 2,500 centigrade. The carbon tube is copper plated at ends and soldered into gun-metal water circulations, which are also arranged as terminals to lead in the current. As shown in illustration, the mounting up of furnace is very simply arranged, the tube being built round with firebricks loosely laid one on the other, the space between filled up with either carborundum or wood charcoal. Voltages up to 20, currents up to 5,000 amperes. These furnaces may also be arranged to work in vertical position. Price, as shown without cable, ij- in. bore by 8 in. long . . £4 3011 301 1T Electric Resistance Furnaces .. .. .. .. .. .. Price £810 The illustration represents our standard type of Electric Resistance Furnace, a large number of which have been sold. As now made it is both the cheapest to run and the most efficient on the market, its superiority being largely due to the general design and the special material employed for heat insulation. The sizes range from 5 in. flat bottom muffle by 3 in. high by about 10 in. long, and from i in. to 5 in. bore by from about 6 in. to 18 in. long for circular tubes, for temperatures up to 1,200 centigrade. For temperatures above 800 centigrade the furnaces are platinum wound ; below this temperature our non- oxidising wire or strip is employed. Wound for any voltage from 50 to 250, and for temperatures from 200 to 1,200 centigrade, current consumption for a 2 in. tube 10 in. long, 200 volts, 1,200 centigrade, 3 amperes. 30121 Ditto, wound with special alloy for temperatures up to 900° C. . . . . £6 10 Prices vary considerably according to voltage and temperature and to the market rate of platinum, and will be forwarded immediately upon receipt of particulars as to dimensions, voltage and temperature required. Supplied with or without regulating resistances. CROSS STREET • HATTCnST GARDETST, E-C 572 w BAIRD &TATLOCK: (LONDON) LTD. * 3013-3014 Combustion Furnaces. 3015 Small Combustion Furnaces, electrically heated, dimensions I in. bore and from 6 in. to 12 in. long, external diameter 3 in. These furnaces as shown are mounted on the ordinary retort stand, and may be used either vertically or horizontally, and form an extremely useful piece of apparatus for the laboratory, one of the chief advantages over the gas heated combustion furnace being the entire absence of fumes and smell. They require very little current and may be connected to the ordinary lamp circuit, the one illustrated 8 in. long consuming a little over one ampere at 200 volts. Made for any voltage from 50 to 250. 3013T Price complete with stand, 6 in. to 9 in. long 3014'' „ ,, „ „ 9 in. to 12 in. long Other diameters and lengths of bore on application. 3015T Electric Resistance Furnace (carbon tube type). This Furnace is similar to the one shown on opposite page, but is mounted on a cast-iron stand with adjustable pillars. The cast-iron base plate or stand is slotted allowing for different lengths of tubes : the pedestals or pillars are arranged to slide in the slots and bolted underneath. The gun-metal water circulations are of massive design with projections cast on for bolting to pedestals from which they are efficiently insulated, and also allowing for cables or leads to be bolted without straining the carbon tube. For temperatures up to 2,500 centigrade. Price as shown in illustration, 3 in. bore tube by 18 in. long, complete with fire bricks. asbestos sheet and charcoal packing Other sizes, vertical or horizontal, on application. 30161 Spare Carbon Tubes, copper-plated and tinned, ready for soldering into water circulations, supplied from stock, 3 in. by 18 in. long, 8/6 each, other sizes in proportion. £0 19 £1 2 £10 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 573 BAIRD &TATLOCK (LONDON) LTD. I I 3017 3018 3019 3020 3021 3017 Fusel Oil Apparatus (Rose's), modified by Herzfield 3018 Fusel Oil Apparatus (Rose's) 3019 Fusel Oil Apparatus, Rose's pattern modified by Bromwell, graduated on stem to .02 cubic centimetres . . . . . . . . . . each, 6/6 ; per doz. See Allen's " Commercial Organic Analysis," vol. i., p. 173, and Leach's " Food Inspection and Analysis," p. 602. 3020 Gas Bottles, thin glass, closed at bottom, ground at top. | i 7d. 8d. lOd. 3021 Gas Deflagrating Globes, welted necks. Capacity Price £0 4 £0 4 £3 15 li 2 2^ litres. . '/- 1/6 1/9 each. 3 5 10 litres. 1/9 2/8 4/2 each. 18/- 30/- 48/- per doz. -, I I "3022 3024 3022 Gas Exploding Tubes, heavy glass, with sole, about 6 in. high x 2 in. diam., each, 8d. ; per doz. £076 3023 Gas Exploding Tubes, heavy glass, without sole, about 9 in. long x i i in. diam., each, 9d. ; per doz. £086 3024 Gas Exploding Bottle, with stopper, strong glass .. .. each, 1/6 ; „ £017 0 CROSS STREET • HATTOTST GARDEN, E-C 574 RAIRD &.TATLOCK (LONDON) LTD. 3025 3027 3028 3029 3025 Gas Deflagrating Spoon for phosphorus, with sliding brass covering disc and cup each, 6d. ; per do/.. 3026 Gas Deflagrating Spoon for phosphorus, larger size, with covering disc 4 in. diameter each, I/- ; per doz. 3027 Gas Deflagrating Spoon, on metal stand . . . . . . . . . . each 3028 Gas Holder, Bunsen, for mercury, with glass stopcock, graduated in millimetres. Capacity, about . . . . . . 250 500 750 grammes. Price . . . . . . . . 6/- .6/9 7/6 each. 3029 Gas Holder, Bunsen, for mercury, without stopcock, graduated in millimetres. Capacity, about . . . . . . 250 500 750 grammes. Price . . . . . . . . 3/9 4/3 5/- each. £056 £0 11 0 £016 / - , 3030 3031 Gas Holders, Plimpton's, for collecting small quantities of gas, on wooden sole, suitable for lecture tables, etc. 8 by 2 in. 10 by i\ in. 3032 12 by 2i in. 3033 Mercury Gasometer, Stead's, with four stopcocks . . 3030 3031 £086 £0 10 0 £0 12 0 £0 14 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. 3034-3041 3042 3043 Gas Holder, Pepys1, stout japanned zinc, with gauge, 3 stopcocks, and long funnel for increased pressure if required, superior workmanship. • 3034s 2 gallons 3035s 4 3036s 6 . . .. 3037s 8 Gas Holder, bright hard rolled copper, with gauge, 3 stopcocks, and long funnel for increased pressure. 3038s 2 gallons 3039s 4 „ 3040s 6 3041s 8 £1 15 £2 0 £2 10 £3 0 £2 10 £3 0 £3 15 £4 10 3042 Gas Holder, Berzelius pattern, of heavy glass, with glass stopcocks well ground to fit. Capacity . . . . . . . . 2.5 5 7.5 10 litres. Price . . . . . . 20/- 24/- 28/- 30/- each. 3043s Gas Holder, Pepys', glass, with metal fittings, superior finish. Capacity Price 15 55/- 25 litres. 75/- each. CROSS STREET • HATTCnST GARDETST, E- C BAIRD &TATLOCK (LONDON) LTD. 3044 3045 3046 3044s Gas Bags, indiarubber, 5 in. wide when flat, with vulcanite stopcock . . 3045s Gas Sampling Tubes, with two stopcocks, 9 by i J in. 3046 Gas Jars, with brass cap and stopcock. Size . . . . . . 8 by 5 Price .. .. .. 6/6 9 by 6 10 by 7 12 by 8 in. 7/- 7/6 9/- each. 3049 Mercury Gasometer, Hempel's, two bulbs, about 300 c.c., on separate wooden stands. . £076 3050 3050s Gas Sampling Tubes, capacity 50 to 60 cubic centimetres, with special three-way stopcock at each end, set of twelve, in polished mahogany case with lock and key . . . . £5 15 0 3051s Gas Sampling Tubes, as above, with special three-way taps . . each £076 (See Fig. 127, page 144, " Practical Physiology," by Drs. Pembrey, Hill, Edkins, MacLeod, and Beddard, 1905, 2nd edition.) ^iEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 577 BAIRD &TATLOCK (LONDON) LTD. 3052 3053 •3052 Gas Trays, glazed stoneware. Diameter Price 3053 Glazed Porcelain Acid Dishes, for bottles, etc. Diameter inside at bottom Price 3054 3 2/9 4 3/9 . af 1/10 5 4/9 2! 21- 6 61- 2/9 9 lO/- in. per doz. 3* 3/9 3054s Fletcher's Collapsing Aspirator for sampling gases. Ebonite ends, indiarubber body, leather strap on each end, with ebonite nozzle and indicator. Capacity, about -fa cubic ft. 3055s Leather case for ditto . . extra in. per doz. £3 15 0 £0 14 6 3056 3057 3056s Reading Table Telescope, on iron tripod base with 18. in. upright. The telescope, which has a magnification of about 6, has a focal length about 3 ft., and can be raised or lowered as required, on the stand. It can also be rotated through any angle in a vertical or horizontal plane £1 12 6 3057s Reading Telescope and Scale. This is the same instrument as No. 3056, with the addition of scale clip and scale. The scale is 50 centimetres long divided into millimetres, and is carried by a clip which slides up or down the stand, and enables the scale to be fixed in any required position . . . . . . . . . . . . . . . . £2 2 < CROSS STREET • HATTOTST GARDEN, E-C BAIR.D &.TATLOCK (LONDON) LTD. 3058 3059 •058' Cathetometer, mounted on heavy iron tripod base with levelling screws, telescope fitted with rack and pinion and spider lines, fine micrometer screw adjustment, focus adjustable from 3 ft. .. .. .. .. .. .. .. .. £9 15 0 0593 Table Cathetometer, for reading accurately the mercury surface in gas tubes, eudiometers, etc. Two feet rod on tripod base with levelling screws, spirit level, fine micrometer adjusting screw . , . , . , . . . . . . . . £5 10 0 iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 579 2P BAIRD c\TATLOCK (LONDON) LTD. 3060-3063 Cathetometer, Horizontal or Vertical. 3066 This instrument has been specially designed for the use of students. It is strongly constructed, and not easily deranged. It consists of a stout brass bar, cylindrical in section and straight, which swings between two hardened steel centres, and can be clamped in any position in azimuth. A millimetre scale runs almost the entire length of the bar. A carriage slides along the bar and is provided with a feather-way, spring, and clamp. One face of the carriage is formed into a dovetail slide, along which for a convenient distance the telescope travels, being actuated by a fine micrometer screw. The position of the telescope is read by means of a vernier attached to the telescope support. The telescope has a focal length of about 7 in., and a clear aperture of £f. an-d is provided with level and cross wires, and is adjustable horizontally. It can be focussed from infinity to within 3 ft. The construction of the stand is such that the instrument can be used either vertically or horizontally. 3060s Cathetorneter, with 50 cm. range, reading to 0.02 mm. 3061s „ ,, I metre ,, „ 0.02 mm. 3062s „ ,, 50 cm. „ ,, .01 mm. 3063s ,, „ i metre „ 3064s Cathetorneter, as above, fitted with reversible telescope, with rack motion . . £7 10 ( .. £10 10 ( . . £8 10 ( .. £12 0 I extra £1 10 ( 30661 Horizontal Reading Microscope. Price, including objective, eyepiece, and micrometer £5 0 This instrument consists of a microscope tube placed horizontally on a column which may by a draw and rack and pinion movement be extended from 34 to 55 centimetres. The column rises from a tripod base provided with a level and levelling screws. A millimetre scale and a vernier indicate to rV millimetre the magnitude of vertical displacements. The microscope tube carries a spirit level, and may thus be made to rotate in a strictly horizontal plane by the adjustment of the levelling screws at the foot of the stand. The objective consists of two separable doublets and gives three magnifications at 5, 9, and 48 centimetres focus respectively, rack and pinion adjust- ment serves to focus the microscope tube. A micrometer, i centimetre long divided in too, in the diaphragm of the eyepiece still further increases the utility of the instrument for fine and accurate measurements. CROSS STREET • HATTOTST GARDETST, E-C 580 3067 )67 Seamless Steel Cylinders (filled to a pressure of 120 atmospheres). 3076 (Prices, see page 582.) Approximate Approximate Cubic external length over all Approximate Price of Contents in diameter in in inches, exclu- Weight in Ibs. Cylinders with feet. inches. ding Valve. (empty). Valve. 10 4 J9 13 .»/- 12 4 23 15 29/6 15 4 27 18 31/- 2O 4 35 23 33/- 40 60 60 54 5i 7 36 50 32 45 66 66 49/6] 59/6- 68/-J 80 7 4i 88 79j- IOO 7 49 no 93/- )68T Oxygen. Nipple union and key extra, 3/9. Quantities of less than 20 cubic ft. Quantities of 20 cubic ft. and less than 60 cubic ft. Quantities of 60 cubic ft. and upwards In Cylinders on Loan. 4d. per cubic ft. 3d. Rent per week after 14 days. 1/3 1/6 2/6 In Customer's own Cylinders. 3d. per cubic ft. 2d. 3069 )69T Carbon Dioxide, in cylinders. Size of cylinder . . . . . . . . 10 20 40 ft. Weight of gas . . . . . . . . 3 7 l6 lbs- Price of gas, per cylinder . . . . . • 4/- 5/- 7/- Price for gas cylinders same price as oxygen cylinders, No. 3067. (These cylinders cannot be supplied on loan.) »70T Carbon Dioxide, in cylinders of 28 lbs., 9/4. Price of cylinder If required for aeration ordinary fittings will do, but if for the production of solid CO2, a special tube to bottom is necessary. £250 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 581 BAIRD ^TATLOCK (LONDON) LTD. 'EGPDFSICN 209731 3071 3073 3077 3071T Sulphurous Acid, liquefied, in glass syphons with tap, holding aboutslbs. Price of gas per Ib. Glass syphons (returnable only for refilling) 3072r Sulphurous Acid, liquefied, in 10 oz. metal cylinders .. each 1/3; per doz. 3073 T Metal Box, nickel-plated, for the production of solid CO2, with jet and coupling 3074T Hydrogen Gas in steel cylinders supplied at same prices as oxygen (see No. 3067). 3075 ' Coal Gas supplied at \A.. per cubic ft. less than the price of oxygen. 3076' Hemp Covers, for transport of cylinders by rail — Size of cylinder . . 10 12 15 20 40 60 80 Price 12 4/6 £0 1 ( £0 6 ( 5/- 5/6 7/6 9/6 100 ft. 13/- 16/- 3078 3079 30771' Folding Lever Key, steel throughout. 1/6 each, black ; 2/3 each, nickel-plated. This key is principally sent out with hired cylinders. When the lever is extended, an increased power is obtained for opening the valve. When closed an ordinary T handle is formed, thus giving reduced leverage for closing the valve, thereby preventing injury to the valve seating. The construction also prevents the valve spindle being turned the wrong way in opening or closing the valve. 30781 Valve Key, wooden handle . . . . . . . . . . . . each £0 2 3079T Gland Nut Spanner . . . . . . . . . . . . . . „ £01 This spanner is useful for tightening up the gland nut of cylinder valves when a leakage of gas is observable round the valve spindle. Cylinder owners should possess one, but it is not supplied with hired cylinders. CROSS STREET • HATTOTST GARDETST, E-C 582 BAIRD &TATLOCK (LONDON) LTD. 3080 3081 5080- Plug for Cylinder Valve Socket 3082 3083-3084 each £0 1 0 This plug is useful to prevent injury to a valve socket. It can be screwed in and out of the valve socket iy means of the ordinary valve key. It is not supplied with hired cylinders. 5081' Fine Adjustment Valve, large pattern Can be obtained on hire at the cost of 6d. per week. each £070 3082' Fine Adjustment Valve, small pattern These valves are not automatic pressure regulators, and consequently must not be used for double lantern .vork. They can only be employed as substitutes for the nipple and union connection, but for this purpose ithey are useful. They give a more delicate means of adjusting the flow of gas from the cylinder than the ordinary Cylinder valve. After they are connected to the cylinder valve the latter may be left open, and all subsequent regulation can bo effected by the fine adjustment valve. Care must, however, be taken to see that no leakage is occurs either in the socket or round the spindle of the cylinder valve. The cylinder valve should be closed as an additional precaution against leakage when the cylinder is not .n use. 3 3083' Gas Pressure Gauge, 4 in. diameter . . . . . . . . . . each 084- „ „ „ 3 „ .. These pressure gauges are useful to frequent users of oxygen cylinders, and particularly to agents, as a .means of ascertaining the quantity of gas in cylinders. They are connected to cylinders in the same way as ihe nipple and union. The gauges, as illustrated, are specially marked in atmospheres and feet, and the cubic contents of any .ylinder may be readily calculated in the following manner : — The figures on outer ring indicate pressure in atmospheres, 120 atmospheres being the pressure to which Jl cylinders are charged. The figures on inner ring indicate the number of cubic feet of gas contained in a zo-ft cylinder. To calculate the quantity of gas contained in any cylinder, multiply the figure to which the needle points by the multiple of in. thus, if the gauge is attached to a 4o-ft. cylinder, and the needle points to 6, then 6 by 4 = 24 ft. = quantity of ..is in cylinder. Both types of pressure gauge are fitted with safety checks in the stem to prevent a sudden rush of gas into the gauge tube when the cylinder valve is opened. Not being makers of pressure gauges, we do not guarantee these articles in any respect. They uc only supplied subject to the purchaser accepting all risk (if any) in respect of them. £060 £1 10 0 £150 Hydrogen and coal gas cylinders are fitted with left-hand ibove fittings are required for these cylinders. thread. Please state when any of CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. 3085 3086 3085' Beard's Automatic Pressure Regulator Can be obtained on hire at the cost of Is. per week. 3086T Tee Piece, as shown, to combine regulator and gauge . . . . • • ,, 3087T Y Piece for same purpose This regulator is extensively used in lantern work. It reduces and automatically controls the pressure and flow of gas from the cylinders, so that after the cylinder valve is opened the gas may be regulated bv the laps on the limelight jet ; a is the delivery nozzle to which the rubber tubing to jet should be connected. each £1 1 £060 £0 6 Stands for Gas Cylinders. 3088 3089 3088T Portable Cylinder Stand, suitable only for 2O-ft. cylinders and under, 5/- and 6/- each. In ordering please state the capacity of cylinder and if fitted with hemp cover. 3089T Cylinder Stand, suitable for 40-ft. cylinders and upwards. Diameter . . . . • • . . 6 8 in. Price .. 9/- 10/6 each. In ordering please state the capacity o/ cylinder and if fitted with hemp cover. CROSS STREET • HATTCTSr GARDEN, E-C 584 BAIRD &TATLOCK. (LONDON) LTD. 3090 3091 3090T Cylinder Stand, suitable for 40-ft. cylinders and upwards. Diameter . . . . . . . . • • 6 8 in. Price . . . . 9/- 10/6 each. In ordering please state the capacity of cylinder and, if fitted with hemp cover. 3091T Cylinder Stand, suitable for 40-ft. cylinders and upwards but only without covers. Diameter . . . . . . 5i 7 in. Price . . 9/- 10/6 each. 3092 3093 3092* Fine Adjustment Valve for connecting to CO.j cylinders The opening is so extremely small that the movement of the segment (B) which controls the valve can easily be regulated by means of the cogwheel and handle. £1 1 0 3093s Respirator, the universal, made of indiarubber, with celluloid cap each, 6/- ; per doz. £3 10 0 BAIRD &TATLOCK (LONDON) LTD. -/ 3094 3094T Acetylene Generators suitable for general lighting purposes and installations. The gas can be used with as much facility as with a town coal-gas supply. The pressure automatically remains constant and sufficient for perfect combustion, therefore a regulating valve or governor is unnecessary, and the lights are always perfectly steady. Water does not drip on to the carbide in the above machine, but rises gently among it, as a result of the peculiar construction of the container. The condensing, washing, and cooling arrangements have received special attention, and the gas always issues in a cool, dry state. PARTICULARS OF PLANT REQUIRED FOR COMPLETE INSTALLATIONS. Approx. Number of Spare Pattern B. Carbide Capacity. burners (average 20 c.p.) Generating Containers supplied for 6 hrs. Chambers. required. No. i 2lbs. 4 I I „ 2 5 ,, IO 2 2 „ 3 9 ,. 18 2 2 ,. 4 15 30 2 2 ,, 5 30 „ 60 2 2 „ 6 60 „ 120 3 3 .. 7 100 „ 200 3 3 PRICES OF COMPLETE PLANTS. Price of Additional Carbide Corresponding Total Cost Pattern B. Generator Complete. Containers, each. Size Purifier. of Plant. £ s. d. i s. d. i s. d. i S. d. No. i £440 £046 £0 15 0 £536 „ 2 £8 10 0 £066 £1 10 0 £10 13 0 ,- 3 £12 10 0 £096 £250 £15 14 0 » 4 £16 15 0 £0 12 6 £350 £21 5 0 ,, 5 £22 10 0 £0 15 6 £4 10 0 £28 11 0 „ 6 £35 0 0 £0 19 0 £550 £43 2 0 » 7 £48 10 0 £150 £6 15 0 £59 0 0 Installations of any magnitude can be erected by connecting two or more generators and purifiers together. CROSS STREET • HATTOTST GARDETST, E-C 586 BAIED &TATLOCK (LONDON) LTD. 3095 Acetylene Generators, for lantern use — PRICES. Carbide Diam. Height. Capacity. Weight Light Capacity. i95 Acetylene Generator, No. i 7 in. 18 in. lib. gjlbs. 2 Burner Jet, 2 hrs. i'961 Acetylene Generator, No. 2 gin. 21 in. 2 Ibs. 13$ Ibs. (3 Burner Jet, 2^ hrs. 1 1 4 Burners, 2 hrs. i'97T Calcium Carbide, in i Ib. tins, with lever lids per tin £150 £1 12 6 £005 Mansfield's Patent Oil Gas Producing Plant for Laboratories. 3098-3100 Simplex Type. Mansfield's Patent Oil Gas Producing Plant is particularly adapted for the use ol scientists whose laboratories removed from the advantages of a supply of town's coal gas. It is a complete plant of great durability and ilicity which will manufacture and maintain a constant supply of gas. The gas is made from any kind of nineral, animal, or vegetable oil) ; it is permanent, will not condense, and has a much greater calorific power All the usual gas appliances used for coal gas are readily adapted for use with oil gas produced References can be given to laboratories in all parts of the world where Mansfield's oil gas is used 1 gas, his system. for maintaining low constant temperatures, as for bacteriological work, the ordinary chemical, physical, agricultural laboratory work, or the maintenance of temperatures as high as 1500° C. for geological and illurgical laboratories. No skilled labour is required either for working or repairs ; every attention necessary ca be given by an ordinary labourer. (See page 588 for prices.) niCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 587 BAIR.D &.TATLOCK (LONDON) LTD. PRICES OF SIMPLEX GAS PRODUCING PLANT (as illustrated on page 587). 3098T Capacity of gasholder, 300 cubic feet ; No. 864 ; Approximate weight, 4 tons . . . . £142 0 3099* „ „ 500 „ ,,866 „ „ 5 ., •• •• £1*2 0 3100T „ „ r.ooo „ ,, 867 ,. „ 8 „ .. .. £260 0 The above prices include packing and delivery F.O.B. Birkenhead or Liverpool. Further particulars on application. 3101 Combustion Tubes, of fused quartz (silica). It is acknowledged that fused quartz is the most suitable for combustion tubes. Such combustion tubes need not be of the more costly transparent material throughout ; it is sufficient that the part of the tube immediately surrounding the boat be transparent, so that the progress of combustion may be observed. Combustion tubes of opaque silica, with a short section of transparent silica tubing interposed, can now be supplied. The standard pattern tube is 3 ft. long, having a 4-in. length of transparent tubing placed at a distance of 12 in. from one end. The prices of these combustion tubes are — 3101T Tubes 12 millimetre bore each £0 16 3102* 3103T 16 20 Other lengths and diameters to order. We are now in a position to supply in fused quartz all forms of chemical and other scientific apparatus at present manufactured in glass, and are at all times willing to give the benefit of our experience to customers who require apparatus constructed to their own designs. I 2 3 4 4* 5 3104 5* 5 6A 3104 Glass Rod (illustrations are full-size section), Nos. i to 6.\ perlb., lOd. ; per Ib. for 28 Ibs. £0 0 1 CROSS STREET • HATTCWT GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. 5 5* 6 6 25 26 Illustrations show approximate full size sections, and thickness of walls. 3105 105 Glass Tubing of finest soda glass, free from lead, specially suitable for glass blowing, etc., of uniform quality and hardness, will not devitrify in the blowpipe flame. Nos. i to 9 and 12 to 16 rice .. Hd. lOd. 10 to ii and 17 to 20 21 to 24 1/3 2/- 1/2 1/10 25 and 26 2/6 per Ib. 2/4 perlb for 28 Ibs. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 589 BAIRD &TATLOCK (LONDON) LTD. A B 3107 (Approximate full size sections). 3107 Soft Glass Tubing, stout walls for " sealed tubes," A or B, best soda glass Glass Tubing and Rod, coloured, J to f in. diameter. 3108 Black or amber 3109 Blue or green (Other sizes specially obtained to order.) 3110 Glass Tubes of Jena composite glass, for sealing, specially adapted for Furnaces No. 2885. per lb.. £0 1 £0 1 £0 2 Length Bore Price 24 13/6 24 19/- 24 in. 24/- per doz. A B C G E F 3111-3113 (Approximate full size sections). 3111 Glass Tubing, manometer for Sprengel pumps, etc., D, E, and F 3112 Glass Tubing, thermometer, plain, .25 to .5 millimetres bore, B and C . . 3113 Glass Tubing, ,, with enamelled back, .25 to .5 millimetres bore, A . . per lb. " 2 3 3114-3115 (Approximate full size sections and thickness of walls.) 3114 Glass Tubing, combustion, Bohemian (Josef Kavalier's), hardest potash glass, Nos. 6 to ii and up to i in. external diameter . •. . . . . . . per lb. 3115 Glass Tubing, combnstion, Bohemian (Josef Kavalier's), Nos. i to SA £0 1 £0 2 CROSS STREET • HATTON GARDEN, E-C BAIRD &TATLOCK (LOTsTDON) LTD. 233* 31 16 (Approximate full size sections and thickness of walls.) U16 Combustion Tubing, new Jena Glass, in length? cf about 1-2 metres. Nos. 7 to 1 1 . . . . . . . . per Ib. „ i to 3 „ 4 to 6A . . . . . . . . . . .*. £0 1 10 £025 £0 2 1 3117 U17 Glass Discs, ground on one side, for gas jars, Nos. 3372, etc. Diameter . . 2 *\ 3 3» 4 4i 5 Price .. 4d. 5d 6d. 7d. 8d. lOd. I/- Glass Covers, for beakers, etc. See Watch and Clock Glasses. 6 1/8 q in. 4/- per doz. 3118 Ramsay's Divider, suitable for dividing tubes, scales, etc., any length up to i metre, consisting of polished mahogany board with grooves for different sized tubes ; steel meter scale, metal slide with steel pointer for marking, clamps, etc., as devised by Prof. Sir William Ramsay, University College, London . . . . . . . . . . £3 17 6 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 3119-3121 - Straight Line Hand Dividing Machine, for dividing thermometer and barometer tubes and flat and bevel-edged scales. The machine is made to the following sizes : — 3119T To divide a maximum length of 13! in. 3120T 31211 24 in. 40 in. DESCRIPTION. This machine, which is well and strongly made, is constructed for dividing thermometer tubes, barometer tubes, and flat or bevel-edged scales. It has a steel leading screw of -5^ in. pitch ; the gun-metal nut is hinged and split so as to be readily disengaged from the screw for moving the carriage quickly along the bed. The ratchet wheel, which is fast on the screw, has 200 teeth. The micrometer wheel is divided into 200 divisions, with figures at every 10 divisions. Thus each division is equivalent to n^y in. traverse. The pivoted cutting frame is fitted with cams and adjustable stops in both directions for making every fifth and tenth divisions larger than the others ; there are ample vertical and horizontal adjustments so that deep or wide articles may be divided. The brass bar on the front of the bed has a dovetail groove along its face, and two small bolts, nuts, and plates are provided for fixing small flat scales whilst being divided. The bar also carries two screw clips for holding thermometer tubes, from £ in. up to ft in. diameter. Besides the above-mentioned pitch of -fa in. the leading screw can, if preferred, be cut to any one of the following pitches, viz., fa m-. A i*1-. 1 millimetre, 2 millimetres, thus altering the amount of traverse per division of the micrometer wheel. The following supplementary parts can be supplied to order, but are not included in the price of the machine : — 1. Tube clips (to fix on brass bar) for holding tubes from f to J in. diameter, or from £ to ijin. diameter ... ... ... ... ... ... ... ... ... per pair 2. A scale, divided to the pitch of the leading screw, and sliding in a dovetail groove the entire length of the bed, and which is read by a pointer fixed to the carriage ... 3. An adjustable sight tube, with lenses attached to the carriage by means of an arm. This is for examining fine scales 4. Dovetail grooves in bed, with bolts, nuts, and plates for fixing special articles and very wide scales With every machine are sent out three tools for marking the tubes or scales : — 1. For glass. 2. For boxwood and ivory. 3. For brass. £1 15 0 £0 16 0 £3 10 0 £100 • CROSS STREET - HATTOTST GARDETST, E-C BAIRD &TATLOCK. (LONDON) LTD. Graduated Apparatus for Volumetric Analysis. All graduated apparatus are calibrated on the basis of the standard litre, i.e. 1,000 grammes of distilled water at 4° C. = 1,000 cubic centimetres, and are adjusted to read correctly at 15° C. Standard Burettes are graduated to deliver the amount stated within the following time limits- Capacity . . . . 10 25 50 TOO c.c. In seconds . . 25-30 35-45 55-6? 70-90 I - f Standard 3123 ] 3122-3125 Standard 3124 Standard 3125 3126 3127 STANDARD BURETTES, VERIFIED AND STAMPED AT THE REICHSANSTALT, CHARLOTTENBURG. 10 25 50 100 C.C. TV T\J TV t 122^ Standard Burettes, with jet and clip o / ~ 71- Si- 101- 123 Standard Burettes, with stopcock Q /« 10/- ll/- 13,1- 124 Standard Burettes, vertical drip stopcock 9/- 10/- ll/- 13/- 125s Standard Burettes, with three-way stopcock for connection with supply bottle 10/6 11/6 12/6 I4/- BURETTES, ACCURATELY GRADUATED FOR ANALYTICAL WORK. 3126 Mohr's Burette, with Geissler's Stopcock. 50 60 75 • 75 100 100 100 5/6 Capacity 10 20 25 25 50 Divided A A * ' A t A A * A Price 2/6 3/- 3/- 3/3 3/6 3/9 5/6 5/3 5/6 3127 Mohr's Burette, with jet, pinchcock, and I.R. tubing complete. Capacity . . . . 10 25 50 50 60 Divided --A A * Price .. 1/8 2/3 2/6 NOTE. — Volumetric Apparatus, except standard quality, calibrated at 80° F. or other tempera- tures, for use in tropical climates made to order only at an additional charge of 10 per cent, on the v.italogue prices. 50 A 2/9 -I 3/9 100 J 3/9 100 A 61- IOO i 4/3 200 c.c. i 7/- each. 200 c.c. i 5/9 each. BAIRD &TATLOCK (LONDON) LTD. BURETTES, SECOND QUALITY, SUITABLE FOR STUDENTS' USE. 3128 Second Quality Graduated Burettes, with stopcock, as Fig. 3126. Capacity . . . . . . . . . . 25 50 Divided & 3, Price .. .. .. .. .. 2/6 3/- 29/- 35/- 100 C.C. A 4/9 each. 50/- per doz. 3129 Second Quality Graduated Burettes, with jet, clip, and I.R. tubing, as Fig. 3127. Capacity . . . . . . . . . . 25 50 100 c.c. Divided .. ^ ^ TV Price .. .. .. .. .. 1/6 21- 3/9 each. 16/- 23/- 40/- per doz. NOTE. — This quality will only be sent when specially ordered. BURETTES, ACCURATELY GRADUATED FOR ANALYTICAL WORK. 3130 3130-3131 3132 3132 Mohr's Burette, with Schellback's enamelled band and blue ribbon in centre, for .correct reading Capacity 10 25 25 50 50 100 IOO C.C. Divided T& i A 3130 Price, with glass stopcock 3/6 3/9 4/- 4/3 4/6 6/6 7/- each. 3131 „ with clip, jet, and I.R. tubing 2/6 3/- 3/- 3/4 3/6 5/6 6/- „ 3132 Mohr's Burette, with patent stopcock, for connection with aspirator bottle. Capacity . . 25 50 IOO IOO C.C. Divided 4 1 Price io i ( ' 4/6 61- 7/6 7/9 each. NOTE.— Volumetric Apparatus calibrated at 80° F. or other temperatures, for use in tropi climates made to order only at an additional charge of 10 per cent, on the catalogue prices. CROSS STREET • HATTOTST GARDETST, E-C I — 'v I JJfi, •M^ BAIRD &.TXTLOCK (LOM)ON) LTD. 3133 3133 3134 3135 3136 3137 3138 3139 3140 3141 3133 Mohr's Burette, with side stopcock and bored stopper ground to fit. Capacity . . 25 50 50 Divided ........ TV £ ^ Price 4/6 5/3 6/- 3134 Ripper's Weighing Burette, 60 cubic centimetres (Chemiker, Zeitung, 1892) 3135 Bunsen's Absorption Tubes, graduated into 250 millimetres 3136 Bunsen's Absorption Tubes, graduated into 250 millimetres, with bulb 100 I 6/9 IOO C.C. I 7/3 each £080 £0 1 6 £0 1 10 3137 Carbon Tubes, uniformly graduated (Eggertz's tubes). Capacity . . . . . . . . 10 Divided . . . . . . . . ^ Price, graduated . . . . . . 2/6 3138 Plain tubes for same, of similar capacity 3139 Erdmann's Burette Floats, for 25 or 50 c.c. burettes 3140 Burette Jet, for use without clip 3141 Burette Jet, glass, ordinary 3142 Burette Caps or Covers, glass 2O 30 c.c. 3/- 4/- per pair. each each, 7d. ; per doz. each . . per doz. £006 £063 £009 £006 £010 I CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 595 2Q _ _ BAIRD &TATLOCK (LONDON) LTD. 3143 3144 3145 3146-3147 3148 3149 3143 Eudiometers, Bunsen's, with platinum electrodes. Graduated in millimetres . . 250 300 Price .. .. .. 3/- 3/3 400 3/6 500 600 800 6/- each. 3144 Eudiometers, Ure's, 50 cubic centimetres, divided to £ cubic centimetre, with platinum electrodes . . 3145T Eudiometers, Cavendish, on mahogany stand, complete with stopcock screwed to fit air-pump 3146 Lecture Eudiometers, with platinum electrodes, glass only, graduated to 60 cubic centi- metres 3147 Metal Stand, with iron tripod base, brass rod, terminals, and clamp, for above . . £0 £1 10 £0 £0 :;: 3148 Gas Measuring Tubes, best quality, accurately graduated. Capacity 10 10 20 20 25 30 Divisions T TO i TS i $ Price 9d. lid. 1/2 1/4 1/3 1/6 30 A 1/9 50 1 2/- 50 * 2/- 50 A 2/4 3149 Gas Measuring Tubes, with stopcock at top. Capacity . . Divisions Price 25 TV 50 75 t 3/- IOO i 3150 Graduated Gas Measuring Tubes, second quality, same pattern as No. 3148. Capacity . . . . . . . . 5« 100 200 Divisions .. .. .. .. .. £ | i Price 1/10 2/10 3/3 .. 21/- 33/- 37 /- IOO 20O C.C ! \ * 3/3 3/6 200 C.C. £ C.C. 5/6 each. 250 c.c. \ c.c. 3/9 each. 43 /- per do 14 • CROSS STREET • HATTCTNT GARDEN, E 596 BAIRD &TATLOCK (LONDON) LTD. 3151 151 Gas Jars, clear glass, on sole with ground rim, graduated and numbered invertly, for measuring gases, etc. Capacity Divided every Price IOO i 1/3 14/- 200 2 1/6 250 2 1/9 20/- 500 c.c. 5 c.c. 2/6 each. 29/- per doz. 3152 3153 STANDARD GRADUATED FLASKS, VERIFIED AND STAMPED AT THE REICHSANSTALT, CHARLOTTENBURG. The basis for the estimation of capacity in the standard measuring vessels is the actual litre = 1,000 grammes i at 4° C. as weighed in vacuo. Standard flasks are adjusted at 15° C. All flasks are graduated to deliver, without allowing for any waiting - Standard Measuring Flasks 50 100 200 250 500 Without stopper .. 1/6 1/9 2/- 2/4 3/3 3153^ With stopper 2/3 2/6 2/9 3/3 4/3 1,000 2,000 c.c. 4/3 6/6 each. 5/3 7/6 ., CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 597 BAIRD &TATLOCK (LONDON) LTD. 3154 3155 3158 FLASKS, ACCURATELY GRADUATED FOR ANALYTICAL WORK. 3154 Flasks, with mark on neck, without stopper, graduated in cubic centimetres. Capacity Price 10 :5 20 25 5° 7° 75 I0° c-c- 3d. 4d. 5d. 5d. 5d. 6d. 6d. 7d. 7d. 7d. each . . 2/9 3/6 4/- 4/- 4/- 5/- 5/6 6/6 6/6 6/6 per < Capacity 150 200 250 270 350 360 400 500 750 800 1,000 2,000 < Price 9d. lOd. I/- 1/2 1/2 1/2 1/2 1/3 1/6 1/6 1/6 2/8 ea 8/6 9/6 11/6 13/- 13/- 13/- 13/- 14/- 17/- 17/- 17/- 30/- 3155 Graduated Measuring Flasks, with mark, unstoppered, new Jena Glass. Capacity . . . . . . 50 100 250 500 Price I/- 1/1 1/5 1/9 3156 Flasks, with mark on neck, without stopper, graduated in grains. Capacity . . . . 1,000 1,500 2,000 5,ooo 10,000 Price .. .. I/- 1/1 1/3 1/6 1/9 III- I2f- 14/- 16/6 18/- 1,000 C.C. 2/6 each. 20,000 grain: 2/6 each. 27/- perdi 3157 Graduated Flasks, with mark on neck, unstoppered, with wide necks, stout glass, suitable for Brewers' Laboratories. Capacity . . . . 100 200 250 300 500 Inside diameter of neck tiffs Price .. 8/- 10/- 13/- 14/- 15/- 3158 Graduated Flasks, with two marks on neck, without stoppers, for sugar analyses. Capacity . . . . . . . . 5° and 55 100 and no Price .. -. .. .. 8d. lOd. 7/6 9/6 515 , in. C.< i* in. 16/- perdci 500 and 515 c. 1/6 each. 17/- perdci NOTE. — Volumetric Apparatus calibrated at 80° F. or other temperatures, for use in troppl climates made to order only at an additional charge of 10 per cent, on the catalogue prices. CROSS STREET • HATTOTST GARDETST, E-C BAIRD &.T&TLOCKL (LONDON) LTD. 1000 c c Giles' Pattern 3159 3163 $159 Graduated Flasks, with mark on neck, and hollow stoppers ground to fit, graduated in cubic centimetres. 5 10 15 20 25 50 5d. 6d. 6d. 7d. 7d. 8d. 4/9 5/6 5/9 6/- •*/- 11- 100 150 200 250 500 515 9d. lid. 1/2 1/3 1/6, 1/9 8/6 10/6 13/- 14/- 171- 201- Capacity Price a Capacity Price H60 Graduated Flasks, with mark on neck, stoppered, graduated in grains. Capacity . . . . . . 500 1,000 Price .. .. ..I/- 1/3 ll/- 14/- H61 Second Quality Graduated Flasks, with mark, unstoppered. Capacity . . . . . . 50 100 Price .. .. 5d. 6d. ..4/6 5/6 (162 Second Quality Graduated Flasks, with mark, stoppered. Capacity . . . . . . 50 100 Price .. 6d. 7d. ..5/6 6/6 5163 Flasks, with bulb in neck, and two marks, stoppered, " Giles' Pattern." Capacity . . . . . . . . 1,000-1,100 Price .. .. .. 4/- 70 75 c.c. 9d. 9d. each. 8/6 8/6 per doz. 1,000 2,000 c.c. 2/- 3/- each. 5,000 10,000 20,000 grains. 1/9 21- 2/9 each. 18/6 21/- 30/- per doz. 250 500 1,000 c.c. 9d. l/- 1/4 each. 8/6 11/6 15/- per doz. 250 500 1,000 C.C. »/- 1/3 1/9 each. 11/6 14/- 20/- per doz. 2,000-2,200 c.c. 5/- each. NOTE.— Volumetric Apparatus calibrated at 80° F. or other temperatures, for use in tropical mates made to order only at an additional charge of 10 per cent, on the catalogue prices. 599 BAIRD &TATLOCK (LONDON) LTD. 3164 3165 3166 Flasks, graduated (ounces), with mark on neck. Capacity . . . . . . . . 5 10 20 40 oz. 3164 Price, unstoppered .. ..1/3 1/6 1/9 2/6 each. 3165 „ stoppered .. .. .. 1/6 1/9 2/- 3/- 3166 Flask, with graduated neck, for oil testing, 225 cubic centimetres (bulb 200 cubic centi- metres, neck 25 cubic centimetres in fifths) . . . . . . . . each £0 3 3167 3168 3167 New Pattern Graduated Flask, for preparing standard solutions. Designed by O. C. M. Davis, Esq., B.Sc., F.I.C., University of Bristol. Price, each, unstoppered, 4/- ; stoppered This flask is graduated to hold i litre, the capacity of the bulb being 975 c.c. and the neck graduated 25 c.c. in -Jth divisions. For accurate reading the neck has white back with blue line down centre. METHOD FOR USING FLASK. In preparing volumetric solutions of substances which cannot be directly weighed with accuracy, it is usual to first make the solutions a little over the required strength and then adjust after titrating with some standard solution. E.G. — It was necessary in a special case to dilute 985.5 c.c. of a solution of Sodium Hydroxide to 1000 c.c. in order to make in deci-normal. In using the ordinary cylindrical measure for such a solution owing to its -wide bore it is difficult to measure the exact volume required. With the flask now introduced this error is avoided and increased accuracy is obtained, also saving of time. 3168 Flask, stoppered, with graduated tube for testing paraffin scale (Mr. D. A. Sutherland's) each £0 4 £0 3 -CROSS STREET • HATTOTST GARDEIST, E-C 600 BAIRD &TATLOCK. (LOM)ON) LTD. «-=-» Standard 3169 Standard 3170 3171 3173 STANDARD GRADUATED CYLINDERS, VERIFIED AND STAMPED AT THE REICHSANSTALT, CHARLOTTENBURG. All standard cylinders are graduated to deliver, without allowing any time for draining. IH695 Standard Cylinders, verified and stamped, with spout. Capacity . . =, 10 25 50 100 Divided .. JT -,'.-, •?, i * Price .. 4/- 4/4 4/6 5/6 5/- 200 f 250 f 6/9 500 1,000 C C. 91- each. 5 10 25 50 IOO 200 250 500 1. 000 c.c. A Tl,r 1 1 .Y 1 f i ! -¥' 4/9 5/- 5/3 6/3 5/6 7/- 7/9 8/9 10/3 each. U70 Standard Cylinders, verified and stamped, stoppered. Capacity Divided Price GRADUATED CYLINDERS, ACCURATELY GRADUATED FOR ANALYTICAL WORK. 5171 Graduated Cylinders, or test mixers, on foot, stoppered, figured to read in both directions. Capacity . . 10 25 30 50 75 Price .. lOd. 1/2 1/4 1/6 1/9 100 200 1/10 2/6 250 3/6 500 4/3 1,000 2,000 C.C. 6/6 9/6 each. 5172 Graduated Cylinders, or test mixers, on foot, stoppered, graduated in grains. Capacity .'. .. .. •• 100 250 500 1,000 5,000 10,000 grains. Price .. .. 1/31/61/92/3 3/9 4/6 each. 5173 Graduated Cylinders, or test mixers, on foot, with spout, figured to read in both directions. Capacity . . 10 25 30 50 75 100 200 250 500 1,000 2,000 c.c. Price .. 9d. lOd. lid. I/- 1/3 1/3 1/9 2/3 2/9 4/6 7/6 each. 5174 Graduated Cylinders, or test mixers, on foot, with spout, graduated in grains, as Fig. 3173. Capacity . . . . . . • • 100 250 500 1,000 5,000 10,000 grains. Price .. 9d. 1/4 1/6 2/- 2/9 3/9 each. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 601 BAIRD &TATLOCK (LONDON) LTD. ,u \m Standard 3177 Standard 3178 3175 3176 GRADUATED CYLINDERS, SECOND QUALITY, SUITABLE FOR STUDENTS' USE. 3175 Second Quality Graduated Cylinders, stoppered, figured to read one way, from bottom to top. Capacity . . . . . . 50 100 250 500 1,000 c.c. Price .. .. 1/2 1/7 2/6 3/- 4/6 each. 13/6 18/6 26/- 35/- 53/- perdoz 3176 Second Quality Graduated Cylinders, with spout, figured to read one way, from bottom to top. Capacity . . . . . . 50 100 250 500 1,000 c.c. Price .. .. lid. I/- 1/7 2/- 3/8 each. 10/- 11/6 18/- 23/- 43/- perdoz. NOTE. — This quality will only be supplied when specially ordered. STANDARD GRADUATED PIPETTES, VERIFIED AND STAMPED AT THE REICHSANSTALT, CHARLOTTENBURG. All standard pipettes are graduated to deliver the required amount within the time limits specified as follows : — Capacity .. i-io 11-50 In seconds .. .. 15-20 22-30 31771 Standard Graduated Pipettes, verified and stamped. Capacity . . i 5 Divisions . . . . ris ^5 Price .. 3/6 4/- 51-100 101-200 C.C. 32-40 45-60 10 25 50 c.c. TTT 16 4/6 5/6 6/- each. 3178T Standard Pipettes, with mark, verified and stamped. Capacity I Price - 1/10 -* read off direct in plain figures over the top edge of the arm. In some cases three or more answers are given simultaneously with one setting of the arm. BACK FACE. Hydraulic powers diameters in versa. Gallons contained in cylinders, pipes, pumps, etc., per foot run, from diameters in inches and fractions and vice versa. Weight of gallons of water per foot run in above and vice versa. Pounds to the decimal of a cwt. and vice versa. Quarters and pounds to the decimal of a cwt vice versa. Shillings to the decimal of a £ and vice versa. Shillings and pence to the decimal of a pound and vice versa. Cwts. to the decimal of a ton and vice versa. £0 12 6 FRONT FACE. inferences from diameters in inches and fractions and vice versa, from diameters in inches and fractions and vice versa. ictres from inches and fractious and vice versa. Centimetres from inches and fractions and vice versa. Decimetres from inches and fractions and vice versa. Parts of a metre from inches and fractions and vice versa. [Sovereigns and shillings to francs and vice versa. Millimetres to the decimal of an inch and vice versa. Decimals of an inch to fractions and vice versa. Decimals of a foot to the fractions of an inch and vice versa. Decimals of a foot to inches and vice versa. Decimal of a shilling to farthings and vice versa. Decimal of a shilling to pence and vice versa. and BAIRD &TATLOCK (LONDON) LTD. 3213 3213T Faber's Improved Calculating Rule, boxwood, 21 in. long, with slide spring with digit registering cursor, and book of instructions . , . . . . . . . . £110 3214s Faber's Demonstrating Rule, with book of instructions DESCRIPTION. This demonstration rule is 98 in. long. Of this length the scales occupy 79 in. They are therefore distributed in eight times the space occupied on the Faber rules of regular length, the position on either rule, whether long or short, being thus in exact proportion to each other. The back of the slide has the scales for sines, logarithms, and tangents. Firstly. The scale has been made about f in. longer at each end, this extra length being provided with the object of affording a firmer hold for the cursor when nearing the extremities of the scales. Secondly. The sliding cursor has been somewhat lengthened in order to provide a graduated scale, which, as will be seen, is divided into 12 equal parts with the figure o in the centre and graduations to 6 plus and 6 minus respectively, a small indicator being introduced which can be set to any of these graduations. 'Ihis, it may be mentioned, obviates a troublesome difficulty which has previously existed, whereby during the working of a complicated calculation provisional results, as they were obtained, had to be entrusted to the memory, whereas by the aid of this new digit registering cursor this difficulty is entirely done away with and the various aforesaid provisional results are, as they are arrived at, registered by moving the indicator in the required direction. In addition to the improvements above enumerated, this new scale will be found to possess some minor improvements in the marking of the scales, whereby a quicker reading of results is possible. Full particulars, however, will be found in the books of instructions accompanying each rule. 3215 3215T Calculating Slide Rule, Barnard's Co-ordinate Spiral in mahogany case with book of instructions This spiral slide rule, which will be found to be of the very greatest possible use to civil engineers and surveyors, is an improvement on our well-known Fuller's rule and is the invention of Mr. H. O. Barnard, of the Surveyor- General's Department, Ceylon. Like Professor Fuller's rule, it enables the user to perform, with speed and accuracy, arithmetical computations involving : — multiplication, division, proportion, continuous fractions, roots and logarithms ; but, in addition, the natural and logarithmic values of trigonometrical functions of any angle can be determined by inspection with the same accuracy as in numerical computation, while the products, quotients, etc., of these functions by lengths or numbers, integral or fractional, are obtained with equal ease, rapidity an I precision. £400 £400 610 ess? BAIRD StTXTLOCK (LONDON) LTD. 3216 216T Calculating Slide Rule, Prof. Fuller's, having a logarithmic scale of numbers 41 ft. 8 in. in length, which is equivalent to a straight rule 83 ft. 4 in. long in mahogany case 217T Calculating Slide Rule, as above, with scale of sines on the fixed cylinder 10 1 Mil METRE2 B«IRD S TUTLOCK. (LONDON) LTD. v 6 M 8 m 0? 3218-3219 218 Boxwood Scales divided into inches and tenths of an inch along one edge, and into centi- metres and millimetres along the other edge . . i metre long, each, 1/7 ; per doz. 219 Boxwood Scales, as above .. .. £ ,, ., ,, 1/1 ; ,, £300 £3 15 0 £0 18 0 £0 12 0 3220-3221 220 Boxwood Scales, divided into centimetres and millimetres on one edge £ metre long, each, lid. ; per doz. 221 Boxwood Scales, as above 1/3 ; £0 10 0 £0 14 0 LLJ_Lj_!_U • M ^f 1 H J-LLLLLLI U_!_L •J-^-M' " si ' >' :|in^"i 1 1 1 y n 1 1 1 1 1 1 y i T n 1 1 1 1 ij 1 1 1 1 1 1 1 MJ 1 1 1 mym xui •• fi CHDONIL T» Bit m iii *ie tie tie Eii zra iiz o 1-il — !!! — '!' 'I1 *!' '!' !! liml---iiliiiilinilmilaiiLiliiiilinilniilii!ili'iil'iiliiiiliiiiliHjiiiiLilmJiiJ 3222 222 Boxwood Scales, 12 in. long, marked one edge inches in tenths, and the other edge in centimetres and millimetres, both edges bevelled . . . . each, 4d. ; per doz. £036 223 Boxwood Scales, 9 in. long „ 3d. ; £026 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 611 2 R •---=>« BAIRJD &TMLOCK (LONDON) LTD. 3224 3224 Demonstration Rod, i metre long, with one plain and the other three sides graduated into decimetre, centimetre, and millimetre, to illustrate the metric system . . each £036 BAIRD 8. TAT LOCK (LONDON) U'.° 1 4 3 YAlRD 3225 3225 Copy of Standard Yard Measure, in boxwood, brass tipped, divided into inches, J, J, and Jj in. . . . . . . . . . . . . . . . . each £0 1 3 [ ; 2 j 1 ] 0 1 i i? 1 | BAIRO S TATLOCK (LONOONlL™ ^ c 8 6 3 9 3 -i S 9 3 S 3 t- Lj Z g » s 5 t 3226 3226 Boxwood Rule, 30 cm. long, with bevelled edges, divided into centimetres along one edge, and into inches and half inches along the other edge . . each, 4d. ; per doz. £0 These rules are useful for practice in estimating tenths. Measurements made by estimate can be checked by direct measurement with a scale divided into millimetres and tenths of an inch. Y\ \\ \ \ \ \ \ \-\ \ \-\ \ \ \ \ \ Section. 3227 3228 3227 Boxwood Measures or Rules, 12 in. long, triangular section, graduated inches on one side in tenths and millimetres on other side .. .. each, 1/6; per doz. £0 17 ' 3228 Steel Rule, folding, divided into inches and tenths on one edge, and into centimetres and millimetres on other edge . . . . - . . . i ft. long, 3 folds, each £0 1 3229 Steel Rule, in leather case, for the pocket . . £0 2 CROSS STREET • HATTOTST GARDE1ST, E-C 612 BAIRD &.TATLOCK (LONDON) LTD. 3230 ?30 Steel Rule, ij in. wide, divided into inches and fractions of an inch along one edge, and into centimetres and millimetres along the other edge ; 10 cm. in £ mm., remainder in i mm. div. ; i in. in TJC in., 3 in. in •£$ in., i in. in -^ in., remainder in jfo in. div. Scale figured 60 cm., and 2 ft. . . . . . . . . . . . . each £050 3231 3232 ;31 Steel Rule, 12 in. long, divided into inches, centimetres and millimetres ; inches on one edge, millimetres on other edge .. .. .. each, 1/9; per do/. £100 332 Steel Rule, divided into inches and tenths along one edge, and into centimetres and milli- metres along the other edge . . . . i metre long, each, 3/6 ; per doz. £200 0123 4 5 € 7 8 < > I0\ i 1 T i 3233-3234 333 Scales, cardboard, graduated for use in a horizontal position 2 34 Scales, cardboard, graduated for use in a horizontal position J metre long, per doz. £020 i £029 25 24 23 22 21 BAIRO A TATLOCK (LONDON) L"> 0 4321 1234 21 22 23 24 25 3235-3236 3i?5 Scales, cardboard, i metre long, graduated in millimetres with zero in centre of scale, figured 50-0-50 . . . . . . . • • • • • • P^ doz. £030 3J56 Scales, cardboard, % metre long, 25-0-25 . . . . . . . . per doz. £026 3237 3117 Rules, steel, etched, i ft. long, graduated into inches and millimetres, suitable for school use ...... each, 7d. ; per doz. £066 1 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 613 BAIRD c^TATLOCK (LONDON) LTD. IA1BD ITITIOCI (u !!• L^lllll 11^^= 12 3238 3238 Improved Steel Drawing Scale, 14^ in. by i£ in. by T^ square edges . . each £0 4 This scale is intended to take the place of the ordinary boxwood scale with diagonal ruling, which is usually found in boxes of drawing instruments, but are practically useless. The illustration shows the top side, one edge of which is divided into inches and izths, 24ths, etc., and the other edge into inches and loths, 2oths, etc. The middle part is divided so that with beam compasses any measurement up to 13 inches may be taken off in TJ5ths of an inch. The other side is divided into millimetres on one edge, and into inches, i6ths, 32nds, etc., on the other edge, and the centre part is for beam compasses to one-tenth of a millimetre (steel nickel-plated). 99 98 97 96 95 94 = 93 = 57 56 55 54 53 52 51 IL 5 5 43 44 45 4fi 47 48 49 50 C Ms = 5 10 100 _98 10 90 92 QC — ^--^. ?0 — _r:= 3239 3240 3239 Boxwood Scale, divided for use in a vertical position into centimetres and millimetres. Graduated on both edges, one reading upwards, the other downwards — £ metre long, each, 1/1 ; per doz. £0 12 i „ „ „ 2/1; „ £1 4 3240 Scales, varnished on thin cardboard, divided into millimetres, graduated for use in a vertical position . . . . . . . . . . . . J metre long, per doz. £0 2 3241 Scales, vertical, on thin cardboard, graduated into millimetres, figured every 2 centimetres lo read in either direction . . . . i metre long, each, 3d. ; per doz. £0 CROSS STREET • HATTOTST GARDETST, E- C 614 BAIRD &TATLOCK (LOM)ON) LTD. 36 — 35 1 = 34 2 = = 33 3 = = 32 4 = =-^^^5=: r== 3 33 = == 2 34 =• — 1 35 = — 0 36 100 BAIRD & TATLOCK 3245 3246 3242 3243 3244 242 Scales, as above, but graduated to read 36 inches in ^ in., figured every inch each, 3d. ; per doz. 243 Mirror Glass Scales, graduated vertically in millimetres on strips of mirror glass — 300 millimetres long, each 500 1,000 244 Glass Scales, graduated in millimetres on strips of opal glass. The graduations are marked by fine black lines on the white surface of the glass ; graduations vertical 100 millimetres long, each 200 £029 £046 £066 £096 £016 £023 Glass scales, either mirror or opal glass, can be supplied with any special graduations to order. 245 Glass Scales, graduated in centimetres and millimetres and inches and sixteenths of an inch, on plain glass, 10 centimetres and 4 inches . . . . each, I/- ; per doz. £011 0 246 Steel Spring Tape, best English manufacture, graduated in inches and tenths of an inch on one side, and in centimetres and millimetres on the other side. Scale graduated to 6 ft. and 2 metres . . . . . . . . . . . . . . ..£050 247 Steel Spring Tape, as above, but second quality. Scale graduated to 6 ft. and 2 metres £029 248 » „ » „ „ ,. „ „ 3ft- „ i „ £019 249 Steel Spring Tape, best English manufacture, as No. 3247, but small pocket size, graduated in inches and tenths on one side, and in centimetres and millimetres on the other side. Scale figured to i metre and i yard . . . . . . . . . . each £030 The Cases for Nos. 3246-3249 have rounded edges and are fitted with stop action. BAIRD &TATLOCK. (LONDON) LTD. 3250 3250 Graduated Measures of Length, boxwood, 2 ft., one joint, divided into cubic centimetres, millimetres, and corresponding English inches . . . . . . each £0 eJ at i 3251 3252 3253 3251 Tubes, Dr. Muter 's, 200 cubic centimetres, with stopcock, old form, with wood sole 3252 Tubes, Dr. Muter's improved Oleine tube. See Analyst, April, 1889 3253 Muter's Carbolimeter, on wooden sole (See Analyst, 1887, p. 193. 10 per cent, sodium hydrate solution to be used.) £086 £0 10 6 £0 6 6 3254 3254 Spirit Levels, mounted in brass, straight in cases. Length Price 3255 Spirit Levels, mounted in brass, circular, flat. Diameter . . . . Price 3 1/6 3255 4 21- i I/- 6 in. 3/- each. 2 in. 5/6 each. CROSS STREET • HATTOTST GARDETST, E-C 616 BAIRD &TATLOCK (LONDON) LTD. HYDROMETERS FOR USE AT 60° F. Twaddell's Scale, each degree is equal to 5° sp. gr. ; for instance, 24° Twaddell is equal to 1. 12 sp. gr., as 24 X 5 = 120 + 1000 = 1.120 sp. gr. Twaddell No. i o to 24 = i.oo to 1. 12 sp. gr. 2 24 „ 48 = I.I2 „ 1.24 „ 3 48 „ 74 = 1.24 „ 1.37 „ 4 74 „ 102 = 1.37 „ 1-51 „ 5 102 „ 138 = 1.51 „ 1.69 „ 6 138 „ 170 = 1.69 „ 1.85 „ 3256-3257 s' M'H K 3258 3258 Enlarged section of bulb. its' FBI i a < l 3259 !56 Twaddell's Hydrometers, Resistance Glass, Nos. i to 6, with shot, pear-shaped bulb, total length about 8 in. . . . . . . . . each, 1/1 ; per doz. £0 12 6 !57 Twaddell's Hydrometers, Resistance Glass, Nos. i to 6, with mercury, pear-shaped bulb, totallength about 8 in. .. .. .. .. each, 1/3 ; per doz. £0 14 6 !58 Twaddell's Hydrometers, Nos. i to 6, extra strong, will not roll when laid down, or revolve in the liquid .. .. .. .. .. each, 1/6; per doz. £0 17 0 !59 Twaddell's Hydrometers, Resistance Glass, i to 6, with mercury, cylindrical bulb, total length about 6 in. .. .. .. .. .. each, 1/2 ; per doz. £0 13 0 160 Twaddell's Hydrometers, brass, about u in. total length, Nos. i, 2, 3, and 4 each £0 12 0 617 tr BAIRD &TATLOCK (LONDON) LTD. ,u Beautne, for heavy liquids o = i.ooo sp. gr. 10 = 1.075 „ 20 = 1.161 30 = 1.263 40 = 1.385 „ 50 = 1.532 „ 60 = 1.714 „ 70 = 1.946 „ Beaume, for light liquids 60 = .706 sp. 50 = .761 40 = .817 36= .837 30 = .871 26 = .892 20 — .928 10 = I.OOO gr. 3261 Beaume's Hydrometers, Resistance Glass, about 8 in. long, for heavy liquids. 0-25 0-50 0-70° B. Price .. .. 1/3 1/4 1/6 each. 14/- 15j- 17 1- per doz. 3262 Beaume's Hydrometers, Resistance Class, about 8 in. long, for light liquids, 0-60. each, 1/5 ; per doz. £0 16 3263 3263 Specific Gravity Hydrometers, Resistance Glass, mercury, cylindrical bulb, total length 6 in., for testing small quantities of liquids. Range from . . 650 700 750 800 850 900 950° To . . . . 700 750 800 850 900 950 1000° Price 1/9 each; 20/- per doz. ' 3264 3264 Specific Gravity Hydrometers, Resistance Glass, mercury, pear-shape bulbs, total length about 8 in. 650 700 750 800 850 900 950 620 700 800 900° 850 Range from To Price Range from To Range from To 700 700 750 750 800 900 900 950 950 1000 700 700 800 900 1000 1/6 1/6 1/6 1/6 1/6 1/6 1/6 2/- 2/- 2/- 2/- each. 17 1- 17f- 17 /- 17 1- 17 j- 17 /- 17 /- 22/- 22/- 22/- 22 /- per doz. 700 1000 1500 icoo 1200 1400 1600 1800 1000 iioo 1200 1300° 1000 1500 2000 1200 1400 1600 1800 2000 iioo 1200 I30O 1400° Price 2/6 each ; 29/- per doz. 1400 1500 1500 1600 1600 1700 1700 1800 1800 1900 1900 2000° Price 2/6 each ; 29/- per doz. Hydrometers calibrated at 84° F. or other temperatures, desired for use in tropical climates made to order at 10 per cent, on catalogue prices. CROSS STREET • HATTON GARDEN, E-C 618 RAIRD &TATLOCK (LONDON) LTD. . 3265 3269 $265 Hydrometers, set of six Twaddell's, Resistance glass, i to 6, about 7 in. long, with trial jar and thermometers, in mahogany case . . 1266 Hydrometers, specific gravity, six spindles, Resistance glass, about 7 in. long, 700-1000, 50° on each spindle, with jar and thermometer in case, as Fig. 3265 . . E»7 Hydrometers, specific gravity, six spindles, about 7 in. long, 1000-1300, 50° on each spindle, with jar and thermometer in case 68 Hydrometers, as above, six spindles, about 7 in. long, 1300-1600, 50° on each spindle, with jar and thermometer in case 269 Hydrometer Set, specific gravity, seven spindles, Resistance glass, about 10 in. long, one each 700-850, 850-1000, 1000-1200, 1200-1400, 1400-1600, 1600-1800, 1800-2000, all in single divisions, in polished mahogany case, with trial jar and thermometer . . >270 Hydrometer Set, consisting of one standard hydrometer 1000-1053, one hydrometer jar and thermometer in mahogany case, lined with velvet, as used at the Royal Asernal £0 18 6 £0 18 6 £1 1 £1 1 0 6 £1 15 0 £1 10 0 HYDROMETERS, GLASS, AND OTHER INSTRUMENTS FOR TAKING SPECIFIC GRAVITIES OF VARIOUS LIQUIDS OF BEST BRITISH MANUFACTURE, CAREFULLY MADE AND TESTED. 271s Sikes' Hydrometers, glass, round stems, o-ioo, in i° best quality each 72s Sikes' Hydrometers, glass ,, ,, ,, in polished mahogany box with 7 in. ivory scale thermometer. With jar and book separate . . . . complete Sikes' Hydrometers, o-ioo set of five, 20° in each, divided in -Jths with stout 8 in. ivory thermometer etched on the stem, in polished and screwed mahogany box. With book of tables and trial jar. 73s Sikes' Hydrometers, glass, small instruments, about 10 in. long 274s Sikes' Hydrometers, glass, large „ 13 75s Sikes' Hydrometers, glass, 20° above o to o, can be included in above sets, making sets of six £086 £130 £2 15 0 £3 12 6 extra, per set £0 12 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 619 RAIRD &TATLOCK (LONDON) LTD. 3276s Twaddell's Hydrometers, superior quality with ivory scales, Nos. i, 2, and 3 . . per doz. 3277s Twaddell's Hydrometers „ „ ,. „ „ Nos. 4, 5, and 6 . . 3278s Twaddell's Hydrometers, standard quality, Nos. i to 6, 12 in. long divided in Jths each 3279s Twaddell's Hydrometers, set of six standard quality, 12 in. long in Iths with etched stem thermometer and jar with foot in polished mahogany box . . per set 3280s Twaddell's Hydrometers as above, in smaller box with jar separate . . . . per set 3281s Twaddell's Hydrometers as above, small size, 9 in., no foot to jar in box .. per set 3282 National Physical Laboratory Certificates for sets 3279-3281 . . . . extra 3283s Twaddell's Hydrometers, o-io in TVths, standard quality, for gas liquor, 12 in. long each 3284s Twaddell's Hydrometers, ordinary quality, ditto, 9 in., in Iths . . . . „ 3285s Twaddell's Hydrometers, patent bulbs, set of six, Nos. i to 6, in cheap polished mahogany box with flat lid, cloth covered fittings . . . . . . . . per set 3286s Twaddell's Hydrometers as above, with etched stem thermometer and jar in the box 3287s Alcoholometer, Gay Lussac or Tralles, o-ioo per cent. 3288s Alcoholometer, Cartier's, 10-45 3289s Alcoholometer, Gay Lussac, Tralles, or Cartier's, with thermometer in the bulb 3290s Brineometers, o-ioo per cent, of brine 3291s Brineometers, 1000-1300 sp.gr... 3292s Acetometers, for vinegar testing, o-ioo sp. gr. 3293s Ammoniameters, 0-40, paper scales 3294s Accumulator Hydrometers, ordinary flat bulb, 9 in. long, 1000-1250 each, 3/6 ; 3295s Accumulator Hydrometers ,, ,, 6 ,, ,, 3296s Accumulator Hydrometers, pipette type, with rubber ball and pipe 3297s Beads, Specific Gravity, any strength between 750-1600 Other gravities special prices. 3298s Beads, Specific Gravity, spirit beads, set of 12, numbered corresponding to 35 O.P.— 20 U.P. .. .. .. .. .. .. .. .. per set 3299s Beads, Specific Gravity, set of 18, 50 O.P.— 35 U.P. 3300s Beads, Specific Gravity, set of 24, 65 O.P.— 50 U.P. 3301s Cider Hydrometers, showing 1000-1100 sp. gr. and alcohol scale each, 3/- ; per doz. £0 15 0 per set £1 1 0 each , 4/- ; per doz. £250 /» 3/6 ; £200 i the each bulb , 8/- ; „ £4 13 0 » 3/9 ; „ £220 ,, 4/- ; £250 ,, 3/-; „ £1 13 0 » 3/- ; „ £1 13 0 each, 3/6 ; £200 „ 3/- ; £1 13 0 ., 5/-; £2 16 0 i/-; £0 10 0 £066 £0 10 6 £0 14 0 £1 13 0 CROSS STREET • HATT9TST GARDETST, E- 620 I 1 BAIRD &.TATLOCK (LONDON) LTD. •r I)) *•> <•* II is i 3302s Oleometers . . . . . . . . . . . . each, 3/6 ; per doz. 5303s Saccharometers, standard quality, patent bulbs, ranged 1000-1050, 1050-1100, 1100-1150, or 0-25, 25-50 Ibs. per barrel, round or flat stem . . . . . . . . each 5304s Saccharometers, standard quality, cylindrical bulbs, round or flat stem. . 5305s Saccharometers, with both scales, Ibs. and sp.gr... . . . . each, extra 5306s Saccharometers, ordinary quality, patent or pear shape, bulbs 9 in. long, single scale, ranged 1000-1050, 1050-1100, or-iioo-iiso . . . . each, 5/- ; per doz. !307S Specific Gravity Bottles, standard grade, with case and counterpoise . . each 5308s National Physical Laboratory Certificates for above . . . . each, extra • • Sets of Specific Gravity Hydrometers, 9 in. long, ordinary quality, cylindrical shape, 50° in each, with 9 in. etched stem thermometer, 30-120 F. and 0-50 C., with jar (no foot). In polished mahogany box, velvet lined. 1310s Specific Gravity Hydrometers, set of six, 700-1000 . . per set |!311S Specific Gravity Hydrometers „ seven, 650-1000 described ,>312S Specific Gravity Hydrometers ,, eight, 1000-1400 ,.313S Specific Gravity Hydrometers ,, ten, 140 0-1900 / ,, £2 0 £0 11 £0 10 £0 1 £2 16 £0 11 £0 2 £2 5 £2 10 £2 15 £3 10 Ti 0 f, (. 3 () 0 6 0 0 0 0 315s Hydrometers, in Tin Cases, 650-700, specific gravity . . each, 6/- ; per doz. 316s Hydrometers, in Tin Cases, 700-750 up to 1750-1800 . . ,, 5/6 ; 317s Hydrometers, in Tin Cases, 1800-1850, 1850-1900. . .. „ 6/- ; Hydrometers, standard quality, 12 in. long in J°with 12 in. etched on stem thermometer F. and C. and jar on foot in polished mahogany case with lock and key, velvet lined. 3195 Hydrometers, set of six, 700-1000 \ . . . . . . per set 320s Hydrometers „ seven, 650-1000 ' as described 1321s Hydrometers „ eight, 1000-1400 j 322s Hydrometers ,, ten, 1400-1900 ' . . . . ,, £3 10 £3 5 £3 10 £4 2 £5 0 £5 10 £6 15 i) 0 0 0 8 () 0 323s Hydrometers, standard quality, in Tin Cases, 650-700 .. .. .. each 324s Hydrometers, standard quality, in Tin Cases, 700-750 up to 1750-1800 325s Hydrometers, standard quality, in Tin Cases, 1800-1850 and 1850-1900 X P L C 's extra to standard instruments per instrument, 2/9 £0 11 £0 10 £0 11 (. (> (. All above instruments are adjusted at 60° F., but they can be adapted for use at other ^mperatures at a small extra charge. .— f^fr Yil ito!iaSiW:flt^^ 1 ™ •^•"•^••^•••••••••••M^H^^^^^^^^^^^^^^^^^^^^^^^^^^^ Jl 1 621 BAIRD &L TATLOCK (LONDON) LTD, 3326 3331 3332 3326T Fletcher's Thermo -Hydrometers (English Patent No. 12363). Single hydrometers Set of six hydrometers, in hanging case, with divisions each N.B. — In ordering, please state range required, supplied only graduated in specific gravity degrees, 50° on each spindle. £050 £1 5 £020 £030 £030 £036 £076 3328 Argentometer 3329 Urinometer, o° to 60°, ivory scale in leather case, best English make 3330 Urinometer, Dr. Vogel's, two spindles (1000-1020 and 1020-1040) . . . . per set 3331 Urinometer, in case, with graduated immersion tube 3332 Fletcher's Thermo -Urinometer This is an adaptation of Fletcher's patent thcrmo-hydrometer for use as a urinometer. A most delicate and sensitive thermometer is blown in one piece with the urinometer, so that the physician when taking the specific gravity of a sample of urine doe-, not incur the inconvenience of having to employ a separate thermometer, or of making random allowances for differences in temperature. The thermo-urinometer is fitted into a small leather tubular case, which packs inside a graduated urine testing cylinder. The whole is contained in a leather outer case, which may be conveniently carried in the breast pocket. 3333 Urinometer, gilt brass, 6£ in. long over all, o° to 40°, with diabetes scale, in leather case £0 15 0 3334 Ruhemann's Urinometer, as described in Centralblat, 1902, i. 784, and Journal Chem. Society, 1902, ii. p. 435, by L. de Koningh, Esq. . . . . . . . . ..£060 3335 Spirit Hydrometer, underproof and overproof . . . . . . . . each £026 3336 Saccharometer, for brewers' use, showing o to 50 Ibs. per barrel, with directions. In case . . . . . . • . • • • • • • • . . . each £026 3337 Saccharometer, for brewers' use, for taking the specific gravity of beer. Graduated into single degrees, 1040-1080 and 1080-1125, in cardboard cases . . . . each £026 CROSS STREET • HATTON GARDETST, E'C BAIRD &TATLOCK (LONDON) LTD. Metal Hydrometers and Saccharometers. As used in Distilleries and Breweries. 3338 3338 No. 2. Doubly Gilt Sikes' Hydrometer SPECIFICATION. Ball Float . . . . Solid turned. Stems . . . . Best triplet drawn, and engine divided. Weights . . . . Bate's metal. Thermometer . . . . 9-in., ivory scaled, seasoned enamelled tube. Rules . . . . Two — best boxwood, accurately grooved and divided for comparative and reducing and proof purposes. Book of Strengths . . Calculated to 80° F. Assay Jar . . . . Calculated to hold the smallest quantity consistent with efficiency. 3339 No. 4. Sikes' Hydrometer is as particularised above, but is fitted with one rule only— a 9 in. boxwood comparative and reducing rule . . £3 15 0 £350 3340 3340 No. 6 Gilt Sikes' Hydrometer, suitable for small dealer or hotel use. This is construc- tionally the same instrument as No. 3338 SPECIFICATION. Ball Float . . . . Solid turned. Stem . . . . . . Best triplet drawn brass, engine divided. Weights . . . . Metal, to Bate's formulae. Thermometer . . . . Stout 7-in., ivory scale, fitted with seasoned enamelled tube. Case . . . . . . Polished mahogany, velvet lined. Book of Strengths . . Calculated to 80° F. Assay Jar . . . . Clear glass with lip and foot. £326 623 BAIRD &TATLOCK (LONDON) LTD. 3341 3341 No. 8 Sikes' Hydrometer. This is an instrument we have introduced to meet the require- ments of the L.V. trade. It has not the high finish of the preceding instruments, but is thoroughly reliable and accurate, and calculated to answer all tests . . ' . . £1 15 0 Ball Float Stem Weights Thermometer . . Case Rule Book of Strengths Assay Jar ' . . SPECIFICATION. Solid turned. Triplet drawn, engine divided. To Bate's formulae. 9-in., stout ivory scale, fitted with plain seasoned tube io-in., polished mahogany, velvet lined. 9-in., boxwood, comparative and reducing. Calculated to 80° F. Clear glass with lip and foot. 3342 3343 POCKET SERIES, SUITABLE FOR TESTING SMALL SAMPLES. 3342 No. 11 Sikes' Hydrometer. This instrument is strongly recommended as being a thoroughly serviceable instrument, of great portability. The constructional detail is the same as quoted in Hydrometer No. 3338 Case — Highly polished mahogany, constructed to^take the hydrometer, thermometer, weights, and assay jar. Outside measurements, 6;}: by 4j by 2\ in. Assay Jar — Best clear glass, with lip. Capacity 4! ozs. £2 12 6 3343 No. 15 Bate's Saccharometer, for distillers' use. finish Best double-gilt brass of very high Stem . . Poises Thermometer Case . . Assay Jar SPECIFICATION. Best triplet drawn, engine divided, machine engraved. Five, ranging from 970-1120° sp. gr. Stout gilt brass scale, fitted with seasoned enamelled tube. Polished mahogany, cloth lined. Best clear glass with lip and foot. £400 CROSS STREET • HATTOTST GARDETST, E-C 624 ^ja> BAIRD &TATLOCK (LO:NDON) LTD. 3344 No. 16 Bate's Saccharometer, for brewers' use. Facsimile of excise instrument. This instrument is of the same specification as No. 3343 with the following exception :— . . Poises — Five, ranging from 1000-1150° sp. gr. 3345 3345 No. 22 Improved One-Weight Saccharometer. Showing from 1000-1140° sp. gr. Best double-gilt brass of high finish SPECIFICATION. Stem . . . . Weight . . Thermometer . . Case . . . . Book of Tables Assay Jar . . Best triplet drawn brass, engine divided and machine engraved. One, polished brass. Stout silvered brass scale, fitted with seasoned enamelled tube. Polished mahogany, velvet lined. Showing corrections on account of temperature from 50-150°. Best clear glass with lip and foot. 3346 Pair of Saccharometers, ranging 1000-1070° and 1070-1150°, or any range to order, fitted in mahogany case 3347 Gilt Metal Saccharometer, fitted in mahogany case, with hard drawn stem, ranging from 1000-1100° sp. gr. double degrees £400 £2 17 6 £200 £110 |S'n|""|S'n TrT§TT ^""""fe"' "g^^' ^^^^^^•^•^^^^^^^^^• 3348 3348 Gilt Metal Saccharometer, fitted in mahogany case, same pattern instrument as above, but showing from 1000-1060° sp. gr. single degrees . . . . ..£110 I I 1 I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I U ; - -I IUT 'ru '- 3349 3349 Gilt Metal Saccharometer (in tin case) showing from 1000-1060° sp. gr. single degrees £0 17 6 3350 Gilt Metal Saccharometer (in tin case) ranging from 1000-1060° sp. gr. single degrees . . £0 17 6 625 BAIRD &.TATLOCK (LONDON) LTD. 3351 Gilt Metal Saccharometer, in tin case, for indications from 1000-1050° sp. gr. single degrees . . £0 17 6 3352 Gilt Metal Saccharometer, in tin case, scaled for any 40° sp. gr. single degrees . . £0120 Any of the above instruments may be fitted with an equivalent Ibs. per barrel scale at the same cost as quoted for specific gravity. A3352 Gilt Brass Citrometer, fitted in tin case. Nos. i, 2, 3 ..£0126 B3352 Gilt Brass Salinometer, ranging from 0-20°, and divided with blow scale on reverse side, fitted in tin case . . ..£090 c3352 Salinometer, as No. 83352, fitted with range from 0-25°, and equivalent blow scale, in tin case 3353 Gilt Brass Brineometer 3354 Gilt Brass Cartier Hydrometer, 10-40° (or other ranges to order) . £096 £0 14 0 £0 15 0 f 3355 3356-3357 3358 3355 Hydrometer, enclosed in pipette, for taking the specific gravity of acid in accumulators, each £030 3356 Nicholson's Hydrometers for solids, japanned tin ; small, 20 cms. long 2/- ; large, 26 cms. long 3357 Nicholson's Hydrometer, brass, nickel-plated, 20 cms. long 3358 Nicholson's Hydrometers for liquids. Made all in glass, with graduated stem . . 3359 Salinometers, glass, for marine boilers, in tin cases. A. Pear-shape bulb, paper scale B. ,, „ ivory scale C. Patent bulb, paper scale each £030 £050 £036 £0 1 6 £020 £0 1 4 CROSS STREET • HATTOTST GARDETST, E-C 626 •i^iisa BAIR.D &.TATLOCK (LONDON) LTD. 3360 Saccharometer, glass, Balling's, English make. A. Saccharometer, 0-20° or 30° in | degrees B. „ 0-20° in fifths, 12 in. long C. „ 0-30° in fifths, 13 in. long D. „ with enclosed thermometer in bulb 3361 Saccharometer, glass, Brix's, English make. A. Saccharometer, 0.30°, 30-60°, or 60-90° in J degrees B. „ in fifths, 13 in. long C. with enclosed thermometer in bulb each £029 £056 £060 £096 £029 £056 £090 3362 3362 Hydrometer Jars, with spout in clear glass. •r , 1 /" f f 3364 Length 5 6 6 6 6 7 • 7 7 8 8 in. Diameter ii i 4 ii if ii 2 iJ 2 2t » Price 4d. 5d. 5d. 6d~. 6d. 7d. 8d. 7d. 8d. 9d. each. »» 3/9 4/9 4/9 5/- 5/6 6/- 7/- 6/- 7/6 8/6 per doz. Length 9 9 10 10 10 12 12 12 14 15 in. Diameter 2 2* 2 a| 3 2 2i 3 2* 2 M Price 9d. lid. 9d. I/- 1/3 lid. 1/2 1/3 1/3 1/4 each. ,» 8/- 10/6 8/6 ll/- 14/- 10/6 13/- 14/- 14/- 15/- per doz. 3363 Hydrometer or Trial Jars, widened at top. Height .. .. .. .. 8i 12 16 Diameter at top . . . . . . 2i 3 3 Price .. I/- 1/6 1/9 3364 Sebatier's Ink, for writing on glass, for use with ordinary steel nib 24 in. 3 ,, 2/6 each. per bottle £016 627 2 S BAIRD &TATLOCK (LONDON) LTD. 3365 3367 3365 Bottles, best clear glass, with extra wide mouth, flat-stoppered for pickling specimens, etc. Capacity Height without stopper Diam. of mouth inside Price 60 125 175 250 35» 500 1,000 2,000 c.c. 2i 3i 3i . 3l 4i 5 5* 7i in. ii *! 2 2j 2i 2j 4 4! ,, 4/3 5/- 6/6 7/6 «/- 9/6 16/6 25/- per doz. 50/- 58/- 76/- 88/- 94/- 112 j- 196/- 290/- per gross. 3366 Museum or Specimen Bottles, of clear stout glass, with soles, and flat stoppers. Height .. .. 5 8 9! 12-! i2-i 15^ Diameter . . . . 2 2! 2 2 3j 3| Price .. .. 9/6 15/- 11/9 16/6 24/9 28/6 i8| in. 4 ,• 44 /- per doz. 3367 Museum or Specimen Bottles, clear glass, with soles and hexagonal stoppers. Capacity . . . . . . . . . . . . 100 Price .. .. .. .. .. .. 1/3 14/- 125 grammes. 1/6 each. 17/- per doz. 3368 3368 Specimen Jars, all of uniform height, about 6 in. high, with solid glass bottoms of various heights. Capacity . . 5 10 20 50 100 125 grammes. Price .. .. 7/9 7/9 7/9 8/6 10/9 11/6 per doz. CROSS STRET • HATTON GARDETST, E-C- 628 BAIRD &TATLOCKL (LOM)ON) LTD. - 3369 3370 3371 569 Lecture Cylinders, open at bottom, 40 by 23 cm., with stopper in centre of cover, which is also ground to fit 570 Specimen Jars, with sole and flat stoppers ground to fit, clear glass. Height 2 3 Diameter 2 i Price 6/- &/ Height 6 6 Diameter I* 2 Price 9/6 12/ 3 2 3 3 4 2 4 2* 4 3 3372 £0 15 0 6 in. i „ 6/- 8/- IO/- ll/- 8/6 9/- 10/6 12/6 IO/- 9/- perdoz. 6 6 6 8 8 8 10 10 12 12 in. 2i 3 4 2j 3 4 3 4 3 4 ,, 9/6 12/6 14/6 16/- 22/6 15/6 16/- 30/- 28/- 35/- 32/6 40/- perdoz. !71 Specimen Jars, same sizes as No. 3370, but with glass hook or ring fused on bottom of stopper for suspending specimens. Sizes up to 4 in. high . . . . . . . . . . extra, each Sin. „ .... „ 12 in. „ .... ,, • 172 Glass Jars, clear glass, on foot, with ground flange at top (for specimen or gas jars). £0 £0 £0 Height 4 6 6 6 7 8 8 8 9 9 IO 10 10 in. Diameter 3 1\ 2 3 2 I| 2 3 2 2* I* 2 2i „ Price 7d. 5d~. 6d. lid. 7d. 6d. 7d. lid. 9d. lid. 9d. 9d. 1/1 each. 6/9 4/9 5/6 10/- 6/6 5/6 6/6 IO/-. 8/6 10/- 8/- 8/6 12/- perdoz. Height 10 12 12 12 12 14 14 15 16 18 18 20 24 in. Diameter 3 2 2* 3 4 3 6 2 4 4 5 4 6 „ Price 1/3 lid. 1/1 1/6 2/6 1/10 5/- 1/6 2/9 3/- 5/- 4/- 8/6 each. 14/- IO/- 12/- 16/6 27 /- 20/- 55/- 16/- 30/- 32/- 56/- 45/- 100/- perdoz. (For glass discs ground one side for gas jars No. 3372, see No. 3117.) jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 629 BAIRD &.TATLOCK (LONDON) LTD, 3373 3374 3375 Glass Covers for Specimen Jars, Fig. 3379, edges arrissed. Diameter 2 2\ 3 3^ 4 4^ 567 3373 Glass Covers, plain 2/- 2/6 2/6 3/- 3/6 4/6 6/- 6/6 6/6 3374 Glass Covers, plain, with \ in. hole in centre 3375 Glass Covers, ground at edge 3376 Glass Covers, ground at edge, with \ in. hole in centre 3376 8 7/6 8/6 9/6 9 sy- ?/- 10/- 10 in. 9/- per do; 10/- „ ll/- „ 4/- 4/- 4/- 4/6 4/6 5/6 7/- 7/6 7/6 4/6 4/6 4/6 5/- 5/- 6/6 8/- 8/6 8/6 5/6 5/6 5/6 6/- 6/- 7/6 9/- 10/- 10/- 10/6 ll/- 12/- (Other sizes cut specially to order.) 3377 3378 3377 Jars for holding nitrates, clear glass, with spout and without sole. Capacity . . . . \ \ i 2 3 4 5 litres. Price .. .. 6d. 8d. I/- 1/3 1/9 2/6 3/6 each. 5/6 7/6 ll/- 14/- 20/- 28/- 40/- per doz. 3378 Glass Specimen Jars, of clear glass, oval, with foot and rim, and with clear glass covers, ground at edge to suit, as Fig. 3375. Height Diameter Length Price 6 8 8 9i 10 in. if 2 2 2| 4 ,. 4 4 51 7 8 „ 3j- 3/3 5/- •/• 10/9 each. 341- 36/- 571- 92/- 124/- per di CROSS STREET • HATTON GARDE1ST, E-C 630 BAIRD &TATLOCK (LONDON) LTD. 3379 3380 379 Glass Specimen Jars, clear glass, with sole and ground flange rim, without covers. Height 3344456666 ™ 5^ 6d2. 7l 8d. 9d5. IP 8d. lit. I/- 1/3 I/- 1% 1/8 1/10 4/6 5/6 6/6 7/6 8/6 13/- 7/6 9/6 11/6 I4/- ll/- 17/- «/- 21/- in. each, per doz. Height Height Diameter Price in. 8 8 8 8 9 9 9 9 ™ IO I0 I0 ™ ^4*645674567 1/1 1/7 1/9 2/3 1/9 2/4 2/6 3/- 1/8 2/6 2/9 3/6 4/6 1/7 lay- is/I at/- at/- w/- a?/- 28/6 34/6 20;- 28/6 31/6 «/- 52;- is/- 12 12 12 12 12 15 X5 5 6 7 8 10 5 7 31- 3/6 4/- 5/6 6/- 3/6 4/6 5/6 \\ 34/6 40/- 46/6 64/- 70/- 40/- 46/6 64/- (Other sizes made specially to order, see Fig. 3373-3376 for covers.) Glass Specimen Jars, clear glass, round, with foot and rim, and with plain glass covers. Fig- 3373- 4445666 355234 each, per doz. each, per doz. Height Diameter 3 2 Price Height 6d 8d 9d. lid. lid. 1/5 10d. I/- 1/4 1/6 1/4 5/6 ?/6 8/6 10/6 10/6 17/- 9/6 11/6 15,- 17/6 15/- 19/- 7 7 8 8 8 8 9 9 9 9 10 10 21 m 1/5 1/11 20 2*8 2)- 25/6 2/10 3/6 2/2 3/- ^ 2?/- ill- 221- 25i- 30/6 21/- 28/- 32/6 40/- 23/6 34/6 6 in. each, per doz. in. each, per doz. in. each, per doz. (Covers, Figs. 3374-3376, to order.) BAIRD &TATLOCK (LONDON) LTD. 1 3381 3384 3382 3381 Glass Museum Jars, half round pattern, with one flat side, clear glass, on sole, with ground rim at top and plate glass covers ground to suit jars. Height, including sole Length inside Depth Price Height, including sole Length inside Depth Price 3382 Glass Specimen Jars, round, with sole and brass rim to secure cover, and vulcanite slip to suspend specimens. Height 6J 7 7 8 8 8 9 9 10 10 10 10 12 12 14 in. Diameter 4! 4! 5$ 4! 6 ;J 4! 7^ 3 4 5^ 6i 6 3 51 „ Price 3/- 3/3 4/6 4/- 5/- 7/- 4/6 7/6 3/- 4/- 5/- 6/6 6/- 3/6 7/- each. 4 5 6 6 8 8 10 in. 2 3 4 5 5 6 6 » ij 1 1 2 2J 2| 3 3 » 1/9 2/6 3/- 4/- 5/6 6/6 7/- each. 20/- 28/- 34/- 46/- 64/- 76/- 82/- per doz. . . 12 12 12 15 15 18 in. . . 6 8 10 8 10 10 . . 3 4 5 4 5 5 „ . . 8/- ll/- 15/- 15/- 18/- 21/- each. 93/- 128/- 1751- 175!- 212 / - 245/- per doz. 3384 Basins, heavy clear glass, for specimens, etc., top edge ground for covers (covers extra), see Figs. 3373-3376. Internal diameter . . . . . . 4 5 6 8 in. height . . 2\ 3 4 5 „ Price .. .. .. .. 8d. lid. 1/4 1/9 each. 7/6 10/- 15/- 20/- per doz. CROSS STREET • HATTO^T GARDETST, E-C 632 BAIRD &TATLOCK (LONDON) LTD. 3385 3385 Cylinders, with loose drop-on lid, of strong white glass. Height Price 3386 4 1/10 21/- 35/- 8 in. 5/- each. 59 /- per do?. 3386 Brain Jars, stout glass, with sole and lid, the latter made with rim to sit inside jar to prevent lid slipping off, lids ground to fit. Sizes . . . . . . . . . . 6 by 3 8J by 4^ in. Price . . . . . . 2/6 "4/6 each. „ .. .. .. .. .. 29/- 521- perdoz. 3387 3388 3387 Glass Basins, with sole and rim, lid ground to fit, suitable for specimens. Diameter . . . . 5 6 7 8 Height 4 4 5 5 Price . . . . . . 2/9 3/3 4/9 6/- 10 6 9/6 12 in. 6 „ 14/- each. 3388 Glass Catgut Boxes, of stout white glass, with cover and glass fittings complete, size 14 by 6J by 7 centimetres . . . . . . . . . . . . each £056 3389 Glass Catgut Box, without inside fittings, 14 by 6J by 7 centimetres . . 3390 Bent Glass Bridge, for boxes No. 3388 £036 £016 633 BAIRD ^lATLOCK: (LONDON) LTD. 3391 3391 Catgut Jars, glass, with ground-in stopper and reel. Height . . . . . . . . 7J Inside diameter . . . . . . 5j For .... i 3393 Fitted complete 3392 Glass Jars, No. 3391, without reels. For Price 1/9 i 10/- 10 12 centimetres. 6J 6£ „ 2 3 reels. 2/6 3/6 each. 2 3 reels. 15 /- 18/6 per doz. 3393 Catgut Boxes, of glass, with cover and knob, and inside fittings. Fitted with . . . . . . . . 2 3 Price .. .. .. .. 7/9 ll/ 4 6 reels. 13/- 19/- each. 3394 3396 3394 Catgut Boxes, of glass, Dr. Hagedorn's, 9 centimetres high by 16 by 9 centimetres, complete with four reels . . . . each £0 3395 Inner Box, with holes, for No. 3394 . . . . . . . . . . „ £0 9 6 3 0 3396 Catheter Trough, of white glass, with polished rim, and cover with knob. Height . . . . . . . . 5j 6 Width .. .. .. .. 5i 8 Length . . . . . . . . 19 34 Price .. .. .. .. 3/9 10/- 6 centimetres. 8 38 11/6 each. CROSS STREET • HATTOTST GARDETST, E-C 634 = BAIRD &L TATLOCK (LONDON) LTD. 3397 3398 3399 3400 397 Catheter Tube, of white glass, without foot, with ground-in stopper, 40 by 4^ centimetres each £026 398 Catheter Jar, of stout white glass, on foot, with ground-in stopper, 40 centimetres high by 6 centimetres diameter . . . . . . . . . . . . each £036 399 Catgut Cylinders, for preserving surgical sewing silk in antiseptic solution, of stout clear glass, with loose drop-on lids, 26 by 6 cubic centimetres . . . . . . each £020 400 Glass Supports for Silk, to suit No. 3399 £020 3401 401 Catheter Trough, with lid and without knob. Height Length Width Price 4 20 51 3/3 402 Catheter Troughs, oblong, with rounded corners, without covers. Height . . . . . . . . 5 6 Length . . . . . . . . 25 28 Width .. .. .. .. 5 6 Price .. .. .. .. 1/6 2/3 403 Catheter Troughs, same sizes as No. 3402, with covers with knob. Price .. .. .. .. 6/6 8/- 3402 5 centimetres. 40 7* - 8/6 each. 7 centimetres. 30 7 3/- each. 10/6 each. 'CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 635 BAIRD &TATLOCK (LONDON) LTD. D 3404 3405 3404 Catheter Troughs, with spout, and polished edges, 3^ centimetres high, bottom size inside 3% by 20 centimetres . . . . . . . . . . . . . . each £0 1 ( 3405 Glass Dishes, with cover, for small surgical instruments, 23 centimetres diam. (9 in.) „ £0 3406 3407 3406 Trays for Instruments, of white glass, with vertical walls, and ground and polished rim. Height . . . . 5 6 6| 7 8 centimetres. Length . . . . . . 28 26J 3o| 35 45 Width . . 12 i6£ 18 22 14 Price .. .. 2/6 3/6 4/3 7/- 1 1/- each. 3407 Glass Dissecting Trays, smooth inside and outside, with polished rim, bottom dimensions inside. • »tres. Length . . . . . . 21 23-!- 25 31^ 36^ 42 centimetres. Width . . . . . . 16 i8| 21 26 3iJ 31* Price . . 2/3 2/6 3/3 4/9 8/- ll/- each. - ^^; 3408 3408 Glass Trays, for scalpels, with ribs across bottom. Height Length Width Price 2^ 6 10 centimetres. 19 27 40 4| 12 20 1/6 3/- ll/- each. X*^SN fisost^-^sss^ssssss ( /ifcir' ^ %/ up |f| 14 • CROSS STREET • HATTO>T GARDEN, E-C- JQ 636 BAIRD &.TMLOCK (LONDON) LTD. 3409-3411 Glass Bowls, round, for surgical use. Diameter About 3409 Clear glass .. 3410 Blue „ .. 3411 Ruby „ .. -••••^ 3412 IO 16 22 4 6 9 10,- 14/- 91- 12/- 161- — 33/- 48/- 30 centimetres. 12 in. 27/- per doz. 291- „ 70/- 3412 Glass Basins, and handle (spittoons) 13 centimetres diameter, 6 centimetres deep each, 10d.; per doz. £096 3413 Glass Basins, same as No. 3412, but with spout 10,!. : £096 3414 3415 3416 8 3414 Glass Solution Jars, cylindrical, with tubulure and drop-over lid. Capacity . . . . . . . . 2 4 Price ..' .. .. .. 2/9 4/6 8/- 3415 Glass Solution Jars, with glass stoppers, having a groove cut for admission of air. Capacity .. .. . . 2 3 4 5 6 8 Price .. .. 3/- 3/9 4/6 5/6 6/6 7/6 3416 Glass Solution Jars, with tubulure and ground-on glass sieve. Capacity . . . . . . . . . . 5 Price .. .. .. .. .. 7/6 3417 Douche Vessels, with handle, graduated every £ litre. Capacity . . . . . . I 8 10/- Price 3/6 2 4/6 3417 10 litres. IO/- each. 10 litres. 9/- each. 15 litres. 17/- each. 3 litres. 6/- each. ^CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 3418 3419 3418 Ear Trough, of glass, 18 by j\ centimetres 3419 Bleeding Basins, glass, heart shape. About Price 3420 Blesding Basins, glass, kidney shape. About .. .. .. 20 Price .. .. .. 15 by 10 lid. 22 II- 3422 3421 Tongue Spatulas, of glass 3421 3420 each, 9d. ; per doz. £086 20 by 12 22 by 16 centimetres. 1/3 2/- each. 25 28 31 centimetres. 1/4 1/7 2/- each. 3423 . . per doz. £086 3422 Specimen Jars, clear glass, rectangular on sole with ground flange at top and lid ground to fit with knob. Height Length Width Price D.V ii 12 13 20 5i 3j 8 12 16 5 i 2 4 4* 2/3 a/- 2/3 3/3 9/6 26/- 23/- 24/- 36/- no/- 21 centimetres. 21 10 11/6 each. 136/- per doz. 3423 Glass Jars, oblong, with flat sides, suitable for specimen or battery jars, sides unpolished. Height . . . . . . . . 5i 6| SJ 8 n in. Width .. 3t 4l 4l 6 6 „ Back to front . . . . . . 2 2j 2^ 4 3^ „ Price .. .. .. .. 1/3 1/6 2/6 4/6 5/6 each. CROSS STREET • HATTOTST GARDETM, E-C BAIBD &TATLOCK (LONDON) LTD. 3424 3424 Glass Jars, oblong, with flat sides, back and front polished, suitable for museum jars, etc. A B C . D E F Height . . . . . . 5J 6J 8J loj n 12 in. Width Back to front Price 3425 Glass Covers, plain, to suit jars, No. 3424. Price IR.WASHER 3| 4i 4i 5i 6 6| „ 2 2i 2£ 3 3* 3i » 1/9 2/- 4/- 5/6 7/- 10/- each. A B C D E F 4d. 4d. 4d. Od. Oil. 6d. each. 3426 3427 3428 3426 Bottles, clear glass, suitable for museums, etc., with glass cover held in position by means of a metal screw cap and indiarubber washer. Capacity, 32 oz. ; height, 8 in.; diam. at mouth, 2f in. Per doz., 6/6; per gross 3427s Brain Jars, stoneware, with lids . . each, I gallon, 2/3 ; 2 gallons £3 16 0 £039 3428 Brain Jars, of clear stout glass, with lute for glycerine and drop-on covers with knob. Height . . . . . . 15 15 15 15 20 25 centimetres. Diameter . . . . . . 15 20 25 30 30 30 „ Price 8/6 10/- 12/6 17/- 19/- 21/- each. jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &1XTLOCK (LONDON) LTD. 3430 3429 3431 3429 Ice Calorimeter, Bunsen's. A. Small bulb, 5 by i in. B. Medium bulb, 6 by i| in. . . C. Large bulb, 7^ by 2 in. 3430 Freezing Apparatus, by Carre 3431 Freezing Apparatus, ,, with thermometer tubulure 3432 Freezing Apparatus, on stand, with thermometer 3433 3433 Knives, for cutting glass tubing (best quality) with handle each,!/-; per doz. £0 11 6 u 3434 3435 3434 Knife, for cutting glass tubing, etc., 7 by 4 cm., without handle each, I/- ; per doz. 3435 Pocket Knife, for cutting glass tubing, rod, etc., in bone handle ,, 2/- ; £0 11 £1 3 CROSS STREET • HATTOTST GARDETST, E 640 BARD &TATLOCK (LONDON) LTD. Ammonium Molybdate NH4HMoO4 Acid Hydrochloric (CONCENTRATED) 3436 (full size) 3436 (full size) .436 Labels for Reagents, gummed, varnished, and perforated, new notation with symbols, in books, 330 labels, with extra labels indicated in brackets, and 30 blank labels at end per book LIST OF DIFFERENT LABELS IN BOOK. £0 1 0 Acetic Acid (2). Acetic Acid (glacial). Alculin] Absolute. Alcohol (3). Aluminium. Alumina. Aluminium Sulphate. Amylic Alcohol. Ammonium Acetate (2). Ammonium Carbonate (2). Ammonium Chloride (2). Ammonium Hydrate (3). Ammonium Molybdate. Ammonium Nitrate. Ammonium Oxalate (2). Ammonium Phosphate. Ammonium Sulphate. Ammonium Sulphide (2). Ammonium Sulphocyanide. Ammonia Alum. Ammonium Iron Sulphate. Aniline. Antimony. Amimony Tersulphide. Antimony Trichloride. Antimony Potass. Tartrate. Arsenic Trioxide. Arsenic Pentoxide. Asbestos. Barium Carbonate. Kuiiim Chloride (2). Barium Dioxide. Barium Hydrate. Barium Nitrate. Barium Sulphate. Barium Sulphide. rue. IVnzoic Acid. Bismuth. Hi inuth Trioxide. Bismuth Nitrate (2). Black Flux. Bleaching Powder (2). Bone Ash. Boracic Acid. Horax (2). Bromine. Cadmium Bromide. Calcium Sulphide. Calcium Carbonate (4). Calcium Chloride (4). Calcium Fluoride. Calcium Hydrate (2). Calcium Hypochlorito. Calcium Oxide. Calcium Phosphide. Calcium Sulphate. Camphor. No. No. 59. Carbon (2). 117. *6o. Carbon Disulphide. 118. 61. Carbolic Acid. 119. *6z. Chloroform. '120. 63. Chromium Sesquioxide. 121. 64. Chromic Acid. *I22, 65. Chromium Sulphate. 123. 66. Chromium Chloride. 124. 67. Chrome Alum. "125. 68. Citric Acid (2). *I26. 69. Cobalt. *I27. •70. Cobalt Chloride. *I28. *7i. Cobalt Nitrate (2). 129. 72. Cobalt Oxide. 130. 73. Cochineal. 131. 74. Collodion. '132. •75. Copper. "133. 76. Copper Acetate. *T34- 77. Copper Carbonate. 135. 78. Copper Chloride. "136. *79. Copper Oxide. 137. *8o. Copper Sulphate (3). "138. Si. Copper Ammonium Chloride. *139- 82. Dextrine. 140. 83. Distilled Water. 141. *84. Ether Methylated (2). 142. 85 Ether Sulphuric. 143. 86. Ethyl Acetate. 144. *87. Fehling's Solution. *T45- 88. Formic Acid. "146. 89. Fusion Mixture. *M7- 90. Gallic Acid. 148. 91. Gasoline. 149. 92. Glycerine (2). 150. 93. Gold. *i5i. 94. Gold Trichloride. 152. 95. Graphite. *I53- 96. Gum. 154. *97. Hydrochloric Acid (4). 155. 98. Hydrofluoric Acid. 156. 99. Hydro-fluosilicic Acid. 157. 100. Hydrogen Peroxide. *'58. 101. Indigo. 159. 102. Indigo Sulphate. 160. •103. Iodine. *i6i. 104. lodic Acid. 162. 105. Iron. 163. 106. Iron Filings. 164. 107. Iron Wire (2). 165. 108. Iron Protochloride. *i66. 109. Iron Perchloride (2). 167. no. Iron Sesquioxide. 168. •in. Iron Sulphate (2). *i6g. •112. Iron Sulphide (2). *I7O. 113. Iron Alum. 171. •114. Lead. *I72. •115. Lead Acetate (2). 173. 116. Lead Subacetate. *i~^. Lead Carbonate. Lead Chromate. Lead Nitrate (2). Lead Oxide (2). Lead Dioxide. Lime Water. Lithium Chloride. Lithium Sulphate. Litmus. Litmus Solution. Litmus Papers (blue). Litmus Papers (red). Logwood. Magnesium. Magnesium Carbonate. Magnesium Chloride. Magnesium Oxide. Magnesium Sulphate (2). Manganese Chloride. Manganese Dioxide (3). Manganese Sulphate. Mercury. Mercury Chloride (2). Dimercury Chloride. Mercury Cyanide. Mercury Iodide. Mercury Nitrate. Dimercury Nitrate. Mercury Oxide (3). Methyl Orange. Methyl Orange Solution. Methyl Violet. Microcosmic Salt. Milk Sugar. Molybdic Acid (2). Naphtha. Nessler Reagent (2). Nickel. Nickel Chloride. Nickel Oxide. Nickel Sulphate. Nitric Acid (4). Nitric Acid (fuming) . Nitrobenzene. Oxalic Acid (4). Palladium. Palladium Chloride. Paraffin. Phenacetolin. Phenol Phthaleine. Phenol Pathaleine Solution. Phosphorus. Phosphoric Acid. Picric Acid. Platinum. Platinum Chloride. Plumbago. Potash Alum (2). ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 641 BAIRD &.TATLOCK (LONDON) LTD. No. 175. Potassium. 176. Potassium Acetate. 177. Potassium Antimoniate. 178. Potassium Bromide. 179. Potassium Carbazotate. •180. Potassium Carbonate (2). 181. Potassium Hydrocarbonate. 182. Potassium Chloride. *i83- Potassium Chlorate (2). •184. Potassium Chromate. "185. Potassium Chromate Solution. *l86. Potassium Dichromate (2). '187. Potassium Cyanide (2). •188. Potassium Ferricyanide (2). *i8g. Potassium Ferrocyanide (i). *igo. Potassium Hydrate (2). *igi. Potassium Iodide (2). *ig2. Potassium Nitrate (3). 193. Potassium Nitrite. 194. Potassium Oxalate. "195. Potassium Permanganate (2). 196. Potassium Silicate. 197. Potassium Sulphate. "198. Potassium Sulphocyanide. 199. Potassium Hydrosulphate (2). 200. Potassium Hydrotartrate. *2oi. Potassium Sodium Tartrate (2). *2O2. Pyrogallic Acid. •203. Rosolic Acid. •204. Salicylic Acid. 205. Sand. A3436 Labels in Book Form in tropical climates No. 206. Silica. 207. Silicon. 208. Silver. •209. Silver Nitrate (2). 210. Soap (White Curd). 211. Sodium. •212. Sodium Acetate (4). 213. Sodium Arsenate. •214. Sodium Carbonate (3). '215. Sodium Hydrocarbonate (2). •216. Sodium Chloride. *2i7. Sodium Hydrate (2). *2i8. Sodium Hypochlorite. •219. Sodium Hyposulphite. 220. Sodium Nitrate. •221. Sodium Phosphate (2). 222. Sodium Silicate. 223. Sodium Stannate. •224. Sodium Sulphate. '225. Sodium Sulphite. *226. Sodium Sulphide. 127. Sodium Tungstate. •228. Sodium Amalgam. . '229. Soda Lime (2). 230. Starch-Farina. 231. Strontium Carbonate. 232. Strontium Chloride. 233. Strontium Nitrate (2). 234. Succinic Acid. •235. Sulphur (z). '236. Sulphuric Acid (5). for Reagents as No. 3436, varnished No. 237. Sulphurous Acid. •238. Sulphuretted Hydrogen (2). *239. Tannic Acid. 240. Tartaric Acid (3). •241. Tin. •242. Tin Chloride (2). •243. Turmeric. 244. Turpentine. •245. Uranium Acetate. •246. Uranium Nitrate. *247. Zinc (2). 248. Zinc Carbonate (3). *249. Zinc Chloride (3). 250. Zinc Oxide (3) . '251. Zinc Sulphate (i). 252. Acid Hydrochloric, normal and deci- normal (i each). 253. Acid Sulphuric, normal and deci normal (i each). 254. Iodine Solution, decinormal. 255. Potassium Permanganate (2). 256. Silver Nitrate, decinormal and stan- dard (i each). 257. Soap Solution, Clark's. 258. Soap Solution, Wanklyn's. 259. Sodium Carbonate, normal. 260. Sodium Hydrate, normal. 261. Sodium Hydrate, decinormal. 262. Sodium Thiosulphate, decinorraa!. 24 Blank Labels. but ungummed, for use . . per book £0 1 0 100 Assorted Chemical Labels (Gummed) iol lite) ^: == Baird SI Tatlock (London) Ltd. Cms Sttiet. Halton Garden. London. B.C. Acid fl) if ' , B3436-C3436 B3436 Labels for Reagents, booklet containing 100 as marked with an asterisk in No. 3436, in envelope, varnished and gummed . . . . . . . . . . each £006 c3436 Labels for Reagents, booklet as above, varnished but ungummed, tor use in tropical climates . . . . . . . . . . . . each £0 0 3437 Labels as required for ordinary bench reagents, with duplicates the figure in brackets, in all 246 labels gummed and varnished No. 21. of the acids, indicated by as list detailed £0 0 No. 1. Acetic Acid (2). 2. Alcohol Absolute (2). 3. Ammonium Acetate (2). 4. Ammonium Carbonate (6). 5. Ammonium Chloride (6). 6. Ammonium Hydrate (6). 7. Ammonium Molybdate (2) 8. Ammonium Oxalate (6). 9. Ammonium Sulphate (2). 10. Ammonium Sulphide (6). 11. Barium Chloride (6). 12. Barium Hydrate (2). 13. Borax (6). 14. Calcium Chloride (2). 15. QUcium Sulphate (6). 16. Charcoal (2). 17. Cobalt Nitrate (2). 18. Copper Oxide (2). 19. Ether (?\ 20. Ferric Chloride (2). Ferrous Sulphate (6). 22. Fusion Mixture (6). 23. Hydrochloric Acid, cone. (6). 24. Hydrochloric Acid, dilute (12). 25. Lead Acetate (6). 26. Lime Powder (6). 27. Lime Water (6). 28. Magnesium Sulphate (2). 29. Manganese Dioxide (6) 30. Methylated Spirit (2). * 31. Mercuric Chloride (2). 32. Microcosmic Salt (2). 33. Nitric Acid, cone. (6). 34. Nitric Acid, dilute (12). 35. Platinic Chloride (2). 36. Potassium Bisulphate (2). 37. Potassium Chlorate (2). 38.' Potassium Chromate (2). 39. Potassium Cyanide (2). 40. Potassium Ferricyanide (2). No. 41- 42- Potassium Ferrocyanide (6). Potassium Iodide (2). 43. Potassium Nitrate (6). 44. Potassium Sulphocyanide (2). 45. Silver Nitrate (6). 46. Sodium Carbonate (6). 47. Sodium Hydrate (6). 48. Sodium Hypochlorite (2). 49. Sodium Phosphate (6). 50. Soda Lime (2). 51. Stannous Chloride (2) 52. Starch (2). 53. Sulphuretted Hydrogen (6). 54. Sulphuric Acid, cone. (12). 55. Sulphuric Acid, dilute (12). 56. Sulphurous Acid (2). 57. Tartaric Acid (2). 24 Blank Labels. CROSS STREET • HATTON GARDEN, E-C 1*44 BAIRD &.TATLOCK (LONDON) LTD. Aniline Gentian Violet 3438 (full size). 3438 Labels, gummed and varnished, for bacteriological work, in books containing 200 labels per book £0 1 0 LIST OF LABELS IN BOOK. •i. Agar-Agar Fibre (2). '2. Agar-Powder. 3. Agar-Agar (sterilized tubes). '4. Alcohol Absolute. 5. Alcohol Absolute, 99.5 % (2) •6. Alcohol, 50 % (3). •7. Alcohol, 70 % (3). '8. Alcohol, 90 %. .'9. Alcohol Methylated (2). 10. Alcohol Methylic, puriss (2). 11. Alcohol-Carmine (Grenacher). lea. Pure Alloxan. 13. Alum-Carmine (Grenacher) (2). 14. Alum-Gentian Violet (Unna). [5. Ammonia Picrocarmine (2). Ii6. Ammonium Chloride (pure). 17. Ammonium Hydrate .880. 118. Aniline Oil, pure (2). 119. Aniline-Water, Gentian Violet (Gram) (2). 20. Benzol (2). 21. Bismarck Brown Aqueous (2). 22. Bismarck Brown (Sat. Alcoholic) (2). 25. Borax-Carmine, Aqueous (Grenacher) (2). 24. Borax-Carmine Alcoholic (Grenacher) (25. Camphor. 2<>. Canada Balsam. 17. Carbo-Fuchsine (Ziehl-Neelson) (2). 2$. Carbo-Gentian Violet (2). 129. Carbo-Methylene Blue (2). 30. Carbo-Thionine. 31. Carbolic Acid, loose crystal (2). .32. Castor Oil. 33. Celloidine Shavings. 34. Chromic Acid. '35. Cochineal Tincture (Mayer). |36. Collodion (2). '37. Cotton Wcol (2). 38. Dextrine. 39. Dextrose. (40. Eau de Javelle (2). 41. Eau de Labarraque (2). 42. Ehrlich-Biondi-Heidenhain's Triple Stain. 43. Ehrlich's Triacid Stain for Neutro- philous Granules. 44. Ehrlich's Triple Stain for Eosino- philous Cells. (5- Eosine (Aqueous) (2). j6. Eosine (Alcoholic, ordinary) (2). if 7. Eosine (Satd. Alcoholic). No. •48. Ether (2). •49. Fleming's Solution. •50. Formaline (2). •51. Fuchsine (Aqueous) (2). •52. Fuchsine (Sat. Alcoholic) (2). 53. Gabbet's Bacteria Stain. 54. Gabbet's Methylene (blue). •55. Gelatine (2). •56. Gentian Violet (Aqueous) (2). *57. Gentian Violet (Sat. Alcoholic) (2). 58. Gibbes' Double Stain for Tubercle. 59. Gibbes' Magenta Solution. *6o. Giesou's Solution. *6i. Glucose (2). *6i. Glycerine (2). •63. Gold Chloride. •64. Gram's Iodine, Staining Solution. '65. Gum Acacia. 66. Gum Benzoin. •67. Gum Damar. 68. Gum Sandrac. 69. Guttapercha. '70. Hasmalum (Mayer). *7i. Haematoxyline Acid (Ehrlich). •72. Haematoxyline Ale. (Kleinenberg). 73. Haematoxyline (Boehmer). •74. Haematoxyline (Delafield's). 75. Haematoxyline (Hansen). 76. Haematoxyline (Kultschitzky's) . •77. Hoffmann's Blue. •78. Iodine. *79. lodoform. *8o. Iron-Haematoxyline, Heidenhain, Solution I. *8i. Iron-Haematoxyline, Heidenhain, Solution II. 82. Iron Perchloride. •83. Jenner's Solution for Malarial Para- sites (2). 84. Kernschwarz. 85. Klein's Solution. *86. Leishman's Stain (2). 87. Levulose Syrup. *88. Lithium-Carmine (Orth.). •89. Lithium Picro-Carmine. *go. Loeffler's No. I Solution for Flagellae. •91. Loeffler's No. 2 Solution for Flagellas. *92. Loeffler's Alkaline Methyleneblue for Bacteria. '93. Maltose. *94. Menthol. 95. Mercury. No. 96. Mercury Bichloride (2). 97. Methyl Blue (Aqueous) (2). 98. Methyl Blue (Sat. Alcoholic). •99. Methyl Green (Aqueous) (2). 100. Methyl Violet, Oxalic Acid Solution, Weigert. 101. Methyl Violet (Sat. Alcoholic Sol.). •102. Methylene Blue (Aqueous). 103. Methylene Blue (Borax). 104. Methylene Blue (Carbo). •105. Methylene Blue (Sat. Alcoholic) (2). *io6. Mttller's Fluid. *iO7_ Neisser's Flagella Stain, A. •108. Neisser's Flagella Stain, B. •109. Oil of Cedar Wood (2). *no. Oil of Cloves (2). in. Oil of Eucalyptus. 112. Oil of Lemons. 113. Oil of Orange. 114. Orcein Solution Acid (Unna). *H5. Osmic Acid I % Sol. *n6. Osmic Acid 2 % Sol. "117. Paraffin (4). •118. Peptone Powaer (Witte's) (2). *ng. Phsnol-phthaleine. *I2O. Phloroglucine. •121. Piciic Acid Sol. 122. Picro-Nigrosine (Strassburger) . *I23. Picrocarmine (Ranvier) (2). •124. Piciocarmine (Weigert). 125. Platinum Perchloride. "126. Polychrome-Methyleneblue (Unna). •127. Potassium Iodide (B. P.). 128. Potassium Hydrate Sticks. 129. Potassium Permanganate. 130. Pyrogallic Acid (2). 131. Rubin and Orange Solution * 1 32. Roux's Blue for Diphtheria Bacillus •133. Saccharine. •134. Safranine-Aniline Sol. (Babe's). *I35. Safranine (Aqueous). 136. Sherrington's Fluid. 137. Silver Nitrate. 138. Sodium Hydrate Sticks. 139. Starch. 140. Sulphur. •141. Toisson's Fluid. •142. Urea (a). •143. Vanillin. '144. White Bees' Wax. *I45. Xylol (2). 12 Blank Labels. 3438 Book of Labels as above, varnished, but ungummed, for use in tropical climates each £010 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 643 2T BAIRD &TATLOCK. (LONDON) LTD. Bacteriology and Microscopy Baird K T&ilock (London) Ltd. Cross S(r««l. Hilton Gardtfl. Undon."E.C B3438-C3438 B3438 Labels for Bacteriology and Microscopy, booklet containing 100, marked with asterisk under No. 3438, in envelope, gummed and varnished . . ... . . each £006 c3438 Labels as above, booklet containing 100, marked with asterisk under No. 3438, in envelope, varnished, but ungummed, for use in tropical climates .. .. each £006 Potassium Iodide 3439 (full size) Hydrochloric ft Acid CODC. 3439 (100 labels in box) 3439 Labels for Reagents, gummed and varnished, in cardboard boxes of 100 each labels, per packet £0 0 The following Labels kept in stock, in stout paper boxes, each containing 100 labels of one kind : — ' No. I. 2. 3. 4. 5 Acid Acetic. Acid Acetic (glacial). Acid Arsenious. Acid Boracic. Acid Carbolic. 6. Acid Chromic. 7. Acid Citric. 8. Acid Hydrochloric. 9. Acid Hydrochloric (dilute). 10. Acid Molybdic. 11. Acid Nitric. 12. Acid Nitric (dilute). 13. Acid Nitric (fuming) 14. Acid Osmic. 15. Acid Oxalic. 1 6. Acid Phosphoric. 17. Acid Picric. 18. Acid Pyrogalliq. 19. Acid Sulphuric. 20. Acid Sulphuric (dilute). 21. Acid Sulphurous. 22. Acid Tartaric. 23. Agar Agar. 24. Albumen (from bloo(J). 25. Albumen (egg). 26. Alcohol (absolute). 27. Alcohol (methylated). 28. Alcohol (methylic, pure). 29. Alcohol (Rectified Spirits of Wine). No. 3°. Alum Chrome. Alum (iron). 32. Alum (potash). 33. Aluminium. 34. Aluminium Chloride. 35. Aluminium Sulphate. 36. Ammonium Acetate. 37. Ammonium Bicarbonate. 38. Ammonium Bromide. 39. Ammonium Carbonate. 40. Ammonium Chloride. 41. Ammonium Hydrate. 42. Ammonium Molybdate. 43. Ammonium Nitrate. 44. Ammonium Oxalate. 45. Ammonium Phosphate. 46. Ammonium Sulphate. 47. Ammonium Sulphide.' 48. Ammonium Sulphocyanide. 49. Aniline Oil. 50. Antimony. 51. Antimony Chloride. 52. Antimony and Potassium Tartrate pure (Tartar Emetic). 53. Argol. 54. Asbestos. 55. Barium Carbonate. 56. Barium Chloride. 57. Barium Nitrate. 58. Barium Oxide Hydrate. 59. Barium Sulphate. 60. Benzol. 61. Bismuth. 62. Bismuth Carbonate. 63. Bismuth Chloride. 64. Bismuth Nitrate. 65. Bleaching Powder. 66. Blue Gentian. 67. Blue Methyl. 68. Blue Methylene. 69. Bone Ash. 70. Borax. 71. Borax Carmine. 72. Bromine. 73. Bromine Water. 74. Cadmium. 75. Cadmium Sulphate. 76. Calcium Acetate. 77. Calcium Carbonate. 78. Calcium Chloride. 79. Calcium Oxide. So. Calcium Phosphate. 81. Calcium Sulphate. 82. Camphor Blocks. 83. Canada Balsam. 84. Canada Balsam in Xylol. 85. Carbol Fuchsine. 86. Carbol Methyleneblue. CROSS STREET • HATTON GARDEN, E-C BAIRD &T&TLOCK (LONDON) LTD. No. 87. Carbo Thionine. 88. Carbon Bisulphide. 89. Carmine. I 90. Chalk. I 91. Charcoal. 92. Chlorine Cubes. 93. Chlorine Solution. 94. Chloroform. 95. Cobalt Chloride. 96. Cobalt Nitrate. 97. Copper Foil. 98. Copper Chloride bi Cryst. 99. Copper Oxide. 100. Copper Sulphate. 101. Cotton, Wool. 102. Creosote. 103. Ehrlich's Triple Stain. 104. Eosine. 105. Ether (methylated sp. gr.). 1 06. Fuchsine. 107. Fusion Mixture. 1 08. Gelatine. loy. Gentian Violet. no. Glucose (grape sugar). in Glycerine. ti2. Gram's Iodine Staining Solution. 113. Green Methyl. 114. Gum Shellac. 115. Hsemalum. 1 1 6. Hsematoxyline. 117. Hydrogen Peroxide. 1 1 8. Hydroquinone. 119. Indigo. 120. Iodine. 121. Iron Wire. 122. Iron Perchloride. 123. Iron Protochloride. 1 24. Iron Protosulphate. 125. Iron Sulphide. 126. Lead Acetate. uy. Lead Nitrate. 128. Lead Oxide (litharge). 129. Lead Peroxide. 130. Litmus. 131. LycopodiUm. No. 132. Magenta. 133. Magnesium Carbonate. 134. Magnesium Chloride. 135. Magnesia Mixture. 136. Magnesium Sulphate. 137. Manganese Chloride. 138. Manganese Dioxide. 139. Manganese Sulphate. 140. Marble Chips. 141. Mercury. 142. Mercury Bichloride. 143. Mercury Iodide. 144. Mercury Oxide Red. 145. Mercury Protonitrate. 146. Metol. 147. Microcosmic Salt. 148. Millon's Reagent. 149. Naphtha Coal. 150. Nessler's Ammonia Test. 151. Nickel Sulphate. 152. Oil of Cedar Wood. 153. Oil of Cloves. 154. Orange Methyl. 155. Paraffin. 156. Phenol Phthaleine. 157. Phenylhydrazine. 158. Phosphorus. 159. Picrocarmine. 160. Platinum. 161. Platinum Perchloride. 162. Potassium. 163. Potassium Acetate (extra). 164. Potassium Bichromate. 165. Potassium Bisulphite (meta). 166. Potassium Carbonate. 167. Potassium Chlorate. 168. Potassium Chloride. 169. Potassium Chromate. 170. Potassium Citrate. 171. Potassium Cyanate. 172. Potassium Cyanide. 173. Potassium Ferricyanide. 174. Potassium Ferrocyanide. 175. Potassium Iodide. 176. Potassium Nitrate. No. 177. Potassium Nitrite. 178. Potassium Oxide Hydrate. 179. Potassium Permanganate. 180. Potassium Sulphate. 181. Potassium Sulphocyanide. 182. Pumice Stone. 183. Sand. 184. Silver Nitrate. 185. Soap, Test (Clark's). 186. Soap, Test (Wanklyn's). 187. Soda Lime. 1 88. Sodium. 189. Sodium Acetate. 190. Sodium Bicarbonate. 191. Sodium Bitartrate. 192. Sodium Carbonate. 193. Sodium Chloride. 194. Sodium Hydrate. 195. Sodium Hypochlorite. 196. Sodium Hypophosphite 197. Sodium Nitrate. 198* Sodium Phosphate. 199. Sodium Sulphate. 200. Sodium Sulphide. 201. Sodium Sulphite. 202. Starch. 203. Strontium Nitrate. 204. Sulphur. 205. Tin (granulated). 206. Tin. 207. Tin Bichloride. 208. Tin Binoxide. 209. Tin Chloride (proto). 210. Turmeric Books. 211. Turpentine. 212. Varnish. 213. Violet Gentian. 214. Violet Methyl. 215. Water (distilled). 216. Xylol. 217. Zinc. 218. Zinc (gran.). 219. Zinc Powder. 220. Zinc Sulphate. Labels not in above list printed specially to order in quantities of not less than 1,000 of each 32 Fletcher's Triple Concentric Burners. This is 8J in. extreme diameter, and the three burners arc in one solid substantial casting. Gas consumption at $$ pressure — Centre ring Middle „ .. Outer „ . . The three combined . .... 9 cubic ft. per hour. 20 24 „ 53 Price, as illustrated extra Horizontal pattern, 14 by 6 in. over all. The This heater will deliver i quart of water per |)33 Separate Tripod Stand . . i34 Fletcher's Instantaneous Water Heaters. inlet and outlet are made at the same end. minute, heated from 60° to 125° F. (scalding hot) >35 Water Heater as above, but nickel plated >36 Special pattern for use with hard water. This pattern has the water tubes fitted with plugs at both ends to allow for the entire coil to be cleared inside from all deposits caused by hard or dirty water . . . . . . . . extra £1 £0 £1 £1 10 6 10 17 £050 BAIRD &TATLOCK. (LONDON) LTD. 3537 3537 Fletcher's Patent Instantaneous Water Heaters for Lavatories, etc., double pattern £3 0 This is nearly double the power of small size, but must be used connected to a good flue or in a well-ventilated room. 3538 3538 Fletcher's Standard High Power Concentric Ring Burners, for large vessels. Prices on page 665. CROSS STREET • HATTOTST GARDETST, E-C 664 BAIRD &TATLOCK. (LONDON) LTD. No. Length from Centre of Flame to End of Tube. Diameter of Hole the Ring will pass through. Gas Con- sumption per Hour. Quarts of Water Boiled per Hour (approximate) Gas Supply Pipe required. Price. Price with Tap. 20 18 in. 6 in. 20 ft. 20 1 in. 10/6 12/6 40 181 „ 10 „ 40 ,. 40 8 » 17/6 19/6 60 19 .. 151 „ 60 „ 60 i - 25/- 28/6 100 20 „ 21 „ 100 „ 100 I ,, 38,'- 41/6 200 21! „ 29i » 200 „ 20O I* „ 60/- 1 ^ -" If coupled together, 3/9 per burner extra. / 3539-3542 Section of governor 3539-3542 Fletcher's New Gas Pressure Governors, for equalising the supply, and preventing waste and irregularity. These governors are sent out adjusted to about -fy pressure, which is the best and most economical for general se, provided the gas pipes and meter are not too small for their work. If this is the case, any pressure can be btained with perfect regularity by unscrewing the top cap of the regulator, and adding extra weights on the isc. These weights can be supplied adjusted to any required pressure up to that of the main service. PRICES. 1539 For J in. bore gas pipe . . . . . . . . . . £0 17 6 1540 „ i in. „ .. .. .. .. .. .. .. ..£176 1541 „ i£in. „ .. .. .. .. .. .. .. ..£250 1542 „ 2 in. „ . . . . . . . . . . . . . . ..£3100 These governors, with the exception of the f in. size, which has a screwed joint, are made with gland screws. .•hich renders their fixing a very simple matter. They must be fixed on the outlet pipe near the meter, and must v perfectly horizontal. If not quite level, they are liable to work unsteadily. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS, 665 BAIRD &1ATLOCK: (LONDON) LTD. 3543 3544 3543 Gas Distributers, with inlet, and three stopcocks 3553 3544 Gas Distributers, with inlet, and four stopcocks, the central stopcock being fitted with batswing burner for lighting or bending glass tubes . . . . . . . . (See also Nos. 249-269.) 3545 Asbestos Millboard, best quality, for use over burner instead of wire gauze, and for placing vessels on when hot. £076 Size Price 4 by 4 by if- 5 by 5 by 1/3 6 by 6 by 1/6 9 by 9 by 2/9 12 by 12 by 4/6 ' 12 by 12 by ^ in. 7/6 per doz. 3546 Asbestos Millboard, cut to order, up to 40 by 40 in., at 9d. per Ib. 3547 Uralite, in squares £ in. thick, for use over burner instead of wire gauze and asbestos. 468 I/- 21- 4/- 3548 Asbestos Tape, for lining furnace gutters, \ in. wide 3549 Asbestos Tape „ ,, 2 in. „ 3550 Asbestos Paper 3551 Asbestos Cloth 3552 Asbestos Cord, 3-fold 3553 Lamp Screen, stoneware 3554 Porcelain Ash Tray, for blowpipe work, with tubulure in centre for burner 10 12 in. squares. 5/6 6/6 per doz. per yard £0 0 8 .. £0 1 0 per Ib. £0 2 0 • • » £0 2 0 per yard £0 0 4 each, 1/6 ; per doz. £0 17 0 £009 3555 3555 Automatic Gas Lighters 3556 Refills for above each, 6d. ; per doz. £056 each, 3d. ; per doz. £029 CROSS STREET • HATTO^T GARDETST, E-C &.TATLOCK: (LONDON) LTD. Models for Illustrating Atomic Theory. 3557 B A. Benzene (Baeyer's) formula ; the models are seen from above. B. Dihydrophthalic acid. V 1 7X 9. Maleic acid. j 3557-3558 557s Solid Formulae ; models for use in teaching organic chemistry, by Arnold Eiloart. Price of complete set, consisting of six wooden models, six straight pins, six hinged pins, forty japanned tin caps, with formula, etc. . . . . . . ..£2126 558s Stands for Eiloart 's models, to raise and lower, with swivel joint giving any angle or position. Extra, each £066 (See description in Dr. Eiloart 's " Guide to Stereochemistry." London : Clarence Eiloart. n, Clement's Lane, E.G. Price 4/- net.) ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 667 BAIRD &TATLOCK: (LONDON) LTD. 3559 3559 3559s Models for Illustrating Atomic Theory, designed by Professor Collie. Set consisting of one stand, one cube, six tetrahedra, six supports, twelve hooks, and six bands £2 10 0 i Fig. i 3560 Fig. 2 3560 Fig. 3 3560s A Benzene Model, on one plane, for lecture purposes, by Professor W. R. Lang, University of Toronto . . . . . . - - each £0 15 The Model is intended as an aid to explaining the theory of the constitution of benzene, based on the following characteristics : — Each hydrogen atom bearing the same relation to the molecule. The formation of benzene as a constant product of the decomposition of other members of the aromatic series. The formation of hexa-additive compounds and the ready breaking up of these into a tri-substitution product. The formation of three isomeric di-substitution products. The evident " saturated " nature of benzene. It would be impossible to reconcile these reactions and properties with the carbon and hydrogen atoms arranged as in an open chain. Fig. i of the model shows this : the body is evidently unsaturated. Fig. 2 illustrates that the only way in which the similarity of the linking of all the carbon atoms can be possible is to have the last one linked to the first. The fourth valence of the carbons may be shown — as in the Armstrong-Bayer formula — as acting towards the centre, or the diagonally opposite atoms may be linked together (Claus). If this be done in the model, then an exceedingly stable molecule will be represented. Fig. 3. CROSS STREET • HATTOTST GARDETST, E- C 663 BAIRD &TATLOCK (LONDON) LTD. 3561 3561s Engler's Atomic Models . 3562 £150 Full description with each set. Models for demonstrating isomerism of the sugars and tartaric acids. (See " Organic Chemistry," Part II., by Professor W. H. Perkin, of Manchester University, and Professor Kipping, D.Sc., University College, Nottingham. 3562° Models, small set, consisting of two models with four arms and eight coloured glass balls, and connecting rubber tube . . . . . . . . . . . . per set 35633 Models, complete set of above of twelve, forty-eight coloured glass balls, with connecting tubes £016 3564s Models, larger pattern than Nos. 3562-3563 £090 . . 3/- and £0 18 0 3565 3565 Mortars and Pestles, iron, strong, bowl shape. Height outside Diameter inside Price 3566 Iron Mortars, bell shape, with pestles, heavy make. No. .. .. ..i 3 Capacity . . \ 2 Outside diameter . . • • 5 8 Price .. .. ..2/6 5/- 3566 4 3* 4 3 9 6/6 5 4 9! 4 6/6 6 6 lOf 13/- 6i in. 6 „ 10/6 each. 7 8 18/- 8 12 pints. 13! in. 28/6 each. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. 3567 3567 Mortars and Pestles, iron, bowl shaped, turned inside. No. . . . . . . . . i 2 Diameter inside . . . . • • 3$ 4i Capacity . . . . . . • • i J Price .. .. ..... 2/6 3/9 3568 3 51 2 5f- 4 6 3 5 7 3* 7/6 3568 Mortars and Pestles, best quality agate, with mahogany handles fitted to pestles. Diameter .. .. .. .. .. il 2 z\ 3 Price .. .. .. .. .. 3/64/67/6 12/- Diameter . . . . . . . . . . 4 4i 5 5% Price . . . . . . . . . . 25/- 35/- 50/- 60/- 6 8 in. pints. 8/6 3* in- 18/- each. 6 in. 74/- each. 3569 3569 Mortars and Pestles, genuine Wedgwood composition and manufacture. Pestles fitted with wood handles. No. Outside diameter Price, complete Pestles only No. Outside diameter Price, complete Pestles only )0000 oooo ooo 00 o i 2 3 4 2j 3 3J 3l 4 4i 5 6 6$ in. 10d. 1/2 1/4 1/5 1/6 1/9 2/- 2/3 3/- each. 4d. 6d. 7d. 7d. 7d. 8d. 8d. 9d. 9d. „ 5 6 7 8 9 10 ii 12 7 8 9 10 ii 12 13 14 in. . . 3/9 5/- 6/6 8/6 10/6 12/- 15/- 19/- each .. lid. 1/1 1/2 1/4 2/3 2/6 3/3 „ CROSS STREET • HATTON GARDETST, E-C 670 BAIRD &TATLOCKL (LONDON) LTD. 3570 3570 Mortars and Pestles, Royal Berlin porcelain. No. . . . . . . . . oo Diameter . . . . . . . . 2 Price 8d. 3571-3572 1/3 1/9 4i 2/6 3 5i 3/9 3571 Mortars and Pestles, German porcelain, glazed outside, unglazed inside. Outside diameter . . 2i 3 3j 4 5i 6 7 Price .. .. 4d. 5d. 7d. 9d. 1/2 1/6 2/- 3/9 4/9 6/9 8/6 13/6 17/6 23/- 4 6| in. 5/6 each. 8 in. 2/6 each. 28/- per doz. 3572 Mortars and Pestles, German porcelain, glazed inside and outside ; pestles wholly glazed. Outside diameter . . . . . . 3 3^ 5 6 in. Price .. .. .. lid. I/- 1/9 2/- each. 10/6 12/- 20/- 23/- per doz. 3573 3574-3575 3573 Mortars and Pestles, heavy glass, bottom half ground inside. Outside diameter . . . . 2 3 4 Price .. .. 7d. 9d. l/- 6/6 8/6 ll/- 3576 6 2/- 23/- 3574 Mortars, diamond, polished steel, mounted in gun-metal, diameter of pestle, | in. 3575 Mortars „ „ „ „ „ ij in. 3576 Mortars simple form, diameter of pestle | in. 8 in. 2/9 each. 31 /- per doz. .. £0 16 0 £160 £0 10 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. Mercury Air Pumps. 3577 3578 3580 3577 Mercury Air Pump, Greiner and Friedrich's, with patent stopcock. Capacity of bulb, 250 cubic centimetres, with manometer mounted on stand with drawer for mercury, with reservoir and indiarubber pressure-tubing as illustrated See page 673 for description. 3578 Mercury Air Pump, large model, for physical and physiological laboratories, on polished mahogany stand, with raising and lowering arrangement. Capacity of bulb, 500 cubic centimetres, with reservoir and indiarubber tubing as illustrated 3579 Mercury Air Pump, smaller model. Capacity of bulb, 350 cubic centimetres, mounted on stand, with the raising and lowering arrangement, stand similar to Fig. 3578, with reservoir and indiarubber tubing as illustrated 3580 McLeod Vacuum Gauge. The apparatus consists of a glass mercury bulb, 500 cubic centi- metres capacity, with a tube on top of bulb graduated 0.2 to o.ooi cubic centimetres ; alongside this is a branch tube graduated in millimetres. Mounted on wood stand with mercury reservoir and ratchet to raise and lower. Complete as illustrated £5 10 0 £12 0 0 £9 15 0 £440 CROSS STREET • HATTCHSr GARDETST, E-C 672 BAIRD &TXTLOCK. (LONDON) LTD. DESCRIPTION OF FRIEDRICH'S PUMP (No. 3577), page 672. (Translated from Annalen der Physik und Chemie, Neue Folgo, Band xxix., i886v There are at present three different systems of mercury air pumps in use, viz., the Gcisslor's, the Toopler's, and the Sprengel's. All have their advantages and disadvantages. The inconveniences are, for example, with the Geissler's pump, the many stopcocks necessary ; with the Toepler's, the fragility of the many-branched tube system ; while tlio Sprengel's pump is only useful for certain work. This mercury pump does not claim to remove every possible disadvantage that a mercury air-pump can exhibit, and yet combine in itself all the advantages ; it is only intended to be an easily managed and handy pump, which can be used for all kinds of work, and by which the production of a good vacuum is facilitated. Ibis ;iir-pump shows a very peculiarly constructed principal stopcock. It is a three-way stopcock, but very liiii rent from those of the Geissler's pump. The new three-way stopcock has two borings, which lie oblique to the axis of the stopper. Each time the stopcock is turned, it opens or closes one or the other passage. The advantages of these stopcocks are — 1. The removal of the tiresome furrow formation between collar and stopper in the periphery direction ol the boring, whereby the stopcock easily becomes leaky. 2. In place of the turning, in the Geissler's pump, of 45° to close the principal stopcock, such to be done by a turning of 90° and 180°, which also contributes to the security of the work. Further, the few ground pieces are protected by mercury cups, in order that any casual entrance of air may be guarded against. The Working of the Pump is very simple, as only one stopcock is used. With the rising of the mercury the stopcock is so placed that the mercury in the widened reservoir A covers the stopcock. The purpose of this is to be able to tako up a certain quantity of mercury without any escaping. The stopcock is then closed jy turning it 90°. When, by the sinking of the level in the mercury reservoir, the mercury has run out of the :>ulb, the stopcock is further turned 90° in order to restore connection with the suction tube B. Whenever this tappcns the stopcock is again shut, the mercury compelled to rise, and then the air through the stopcock driven iut, and so on. Should, as by the analyses of the gases of the blood, moist gas be drawn out of the receiver, it s only necessary to use a simple drying apparatus filled with chloride of calcium or other moisture-absorbing naterial. The mercury air-pump can be made to any size, and with or without raising and lowering arrangement. In the fitting up and using the pump, the following practical suggestions may be found of use : — The connections to be made with indiarubber tubing tied firmly with soft iron wire. DRYING APPARATUS. — A small quantity of phosphoric anhydride to be placed in bulb C, and the narrow part above it (D) to be filled with glass wool to prevent the phosphoric anhydride being drawn into the pump. Alter this the mouth of the drying apparatus must be carefully cleansed and greased before the manometer is inserted. The mercury to be used must be pure and dry. Should the pump not act well at first it will be owing to moisture in the tubes, which will be driven off by degrees and absorbed by the anhydrous phosphoric acid. The mercury vessel must always be lifted slowly, otherwise there is a danger of the mercury falling against the stopcock and breaking the pump. The gradual raising of the mercury facilitates also the better working of the pump. The glass tube of the drying apparatus must be connected with the funnel of the pump by means of a soft indiarubber stopper or piece of tubing, and closed by mercury. This is as good as if the parts were ground to fit, and the elasticity prevents breakage. If a high vacuum is required, the vessel to be exhausted should be allowed to remain on the pump for some hours, and slightly warmed by means of a spirit-lamp. 3581 3582 3581 Apparatus for the analysis of blood-gases, by Pfluger 3582 Apparatus for the analysis of blood-gases, by Kronecker Nos. 3581 and 3582 can be fitted to No. 3578. £4 10 0 £4 10 0 BAIRD &TATLOCK (LONDON) LTD. 3585-3586 3588 3585 Mercury Air Pump, for physiological work, etc., on stand, capacity of bulb about i litre, drawer for mercury, complete as illustrated 3586 Mercury Air Pump, for physiological work, etc., similar to above, on stand, capacity of bulb about J litre, drawer for mercury, complete as illustrated • 3587 Mercury Air Pump, small pattern, with cylindrical bulb, capacity about 200 cubic centimetres, drying apparatus, etc., on stand, similar design to Nos. 3585-3586 £550 £500 £3 15 0 3588 Friedrich's New Improved Mercury Pump, arranged to be started and kept in action by water pump, on polished mahogany stand, with indiarubber pressure-tubing, as illustrated £10 CROSS STREET • HATTOTST GARDEN, E-C 674 BAIRD &TATLOCK (LONDON) LTD. A3588 3589 3590 3591 (\3588S Mercury Pump as designed by Drs. Buckmaster and Gardner. The apparatus is a modified Toepler Pump. The apparatus is evacuated in the usual way, and the height of the mercury in the barometer tube so adjusted that it reaches to the entrance to the lower condenser bulb. Price complete with two taps for connection to main water supply and to waste, mounted on teak stand. (See " Journal of Physiology," Vol. 40) . . . . £1200 3589 Sprengel Pump, mounted on wooden stand, with tray for mercury, with one fall tube . . £210 0 with two fall tubes . £350 3590 Sprengel Pump 3591 Sprengel Pump with three fall tubes £450 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 675 2 X BAIRD &.T2tfLOCK (LONDON) LTD. 3592 3593 3592 Mercury Reservoirs, or heavy glass bulbs. 4 8 12 9d. I/- 1/3 8/6 ll/- 14/- 3593 Nitrogen Bulbs, Will and Varrentrap's 3594 Nitrogen Bulbs, with funnel 16 1/6 17/- 3594 24 32 oz. 1/9 2/3 each. 20/- 25/- per doz. each, 8d . ; per doz. £076 9d.; £086 3595A 3595B 3595 Nitrogen Bulbs, improved by Volhard, A or B form 3596 Nitrogen Bulbs, improved by Fresenius 3596 each £0 0 10 £0 1 0 ( 3597 3598 - I 3599 3597 Schiff's Nitrometer, improved, on wood base, with bulb reservoir . . . . . . £09 3598 Schwarz's Apparatus, for determination of nitrogen, graduated 80 cubic centimetres, single divisions, on stand . . . . . . . . . . . . £0 15 ' 3599 Nitrogen Tubes, drum's, with stopcock, graduated 30 cubic centimetres in fifths . . £04 14 • CROSS STREET • HATTOTST GARDEN, E-C BAERD &.TATLOCK (LONDON) LTD. 3600 3601 3603 : 3603 3 )0 Nitrometer, for saltpetre, by Prof. Lunge, a modification of his ordinary nitrometer. The bulb, under three-way stopcock, has a capacity of about 100 cubic centimetres, and the tube attached of 40 cubic centimetres divided into fifths, together 140 cubic centimetres. The auxiliary tube has also a bulb of about 100 cubic centimetres, and the tube above it is graduated into cubic centimetres. The whole apparatus being of very strong thick glass. See article by Professor Lunge in Journal of Society of Chemical Industry, January, 1882, p. 15 . . . . . . . . . . . . . . Price 3'il 3i 3 3(4 ' I 3604 £0 12 0 £0 13 6 Nitrometer, same as above, with new form of stopcock Nitrometer, new form, bulb 100 cubic centimetres, stem 100-140 cubic centimetres in T^ths, with three-way stopcock and reservoir at top graduated to 10 cubic centimetres in single cubic centimetres, with plain auxiliary tube . . . . • • • • £0120 Nitrometer, Allen's, graduated 50 cubic centimetres in fifths . . . . . . £066 Horn's Apparatus, for determination of nitrogen in gunpowder and nitro-cellulose. See Zeitschrift fur Angewandte Chemie, 1892, heft 7, and 1893, heft 12 .. . . - . £100 'I 3605 3606 3607 3608 3609 3610 BAIRD •&. TATLOCK (LONDON) LTD. Lunge's Gas Volumeters. (Illustrations see page 677.) These apparatus, which constitute an important improvement in the manipulations connected with gas analysis, and especially provide for dispensing with the calculations necessary for temperature and pressure, have been designed by Lunge. See Journal of Society of Chemical Industry, May, 1890, p. 547. Two forms are illustrated in this abstract of Lunge's paper, but we subjoin illustrations of the other forms, with a reference to the special work for which they are adapted. For a detailed description of these apparatus see Berichte der Deutschen Chemischen Gesellschaft, No. 4, 1890, Zeitschrijt fur Angeivandte Chemie, 1890. 3605 For estimation of saltpetre, etc., complete with indiarubber tube . . . . . . £14 3606 For estimation of manganese, chloride of lime, complete with indiarubber tube . . . . £16 3607 For estimation of nitrogen in organic analysis, complete with indiarubber tube . . . . £18 3608 For estimation of manganese, bone charcoal, etc., azometric determination, complete with indiarubber tube . . . . . . . . . . . . . . ..£18 3609 For estimation of nitrous bodies, dynamite, nitroglycerol, complete with indiarubber tube £1 16 3610 Universal gas volumeter, complete with indiarubber tube . . . . . . . . £13 3611 3612 3613 3614 Nitrometer, *Tennant's. Consists of a graduated tube with a three-way stopcock. Cup at top and bulb at bottom, and a plain auxiliary tube. Graduated portion divided in fifths 3611 Old form of stopcock 3612 Patent form of stopcock . . 30 6/6 8/6 50 7/6 10/- 100 cubic centimetr 8/6 ll/- 3613 Nitrometer, Dr. Lunge's. Consists of a graduated tube of 50 cubic centimetres capacity in fifths, with three-way stopcock and cup at the top, and a plain auxiliary tube 3614 Nitrometer, same as above, with patent form diagonally bored tap and plain auxiliary tube £0 7 £0 10 CROSS STREET • HATTOTST GARDETST, E-C 678 BAIRD &TATLOCK (LOM)ON) LTD. 3623 Apparatus for testing nitro-glycerine, as devised by Dr. R. Robertson, Research Department, Royal Arsenal, Woolwich. >15 Horseshoe-shaped tube, with double spirals of glass 1 16 Copper bath for heating the above, on stand >17 Jena glass combustion tubes for copper asbestos •18 Small furnace with five Bunsens for heating above • 19 Spiral glass condensing worm, with ground joints and cooling jacket i20 Observation tube •21 Spectroscope, with dense glass prism and camera attachment . . •22 Wills' gas measuring tube, as Fig. 3624, with auxiliary tube and I.R. tubing •23 Complete apparatus as above DESCRIPTION OF APPARATUS. Jena glass wool, soaked in 0.3 to 5 gr. nitro-glycerine dissolved in acetone, which is subsequently evaporated , is placed in the horseshoe-shaped tube, closed by a greased and mercury-sealed plug. A current of CO, can sent down the right-hand spiral, through the glass wool, and up the other spiral, or vice versa, according to - position of the stopcocks. At the upper end of the apparatus is a slip joint, between which and a supporting "t at the bottom the whole apparatus can be rotated about its axis. The CO, used contained only 0.02 per M. of gas unabsorbed by KOH solution, and, to eliminate any oxygen, was passed over red-hot copper asbestos. iral Sl is immersed in an oil bath, the temperature of which is known, and is maintained uniform by a stirrer. serves as a preheating worm for the COa. Spiral S2 is above the heated oil, is protected from it by asbestos rds, and is cooled by an air-blast. It serves to condense any volatilised nitro-glycerine. After a suitable rind the apparatus is rotated through 180 degrees, when the spirals exchange functions. Any nitro-glycerine uch has condensed in S1 is now restored to the system. The gaseous products of combustion are led off for amination through the slip joint by means of fixed glass tubes, the use of indiarubber being thus avoided. a precaution against the carrying over of nitro-glycerine, the gases pass through an ice-cooled worm imme- itely on leaving the decomposition apparatus. The mixture of CO.,, of which the volume is known and rate iform, and volatile products of decomposition was usually passed through an observation tube, in which the icentratiou of NO2 was determined by the spectroscopic method of Robertson and Napper C/-C.S., 1907, xci. i), and from this the weight of nitrogen disengaged in the form of NO, was calculated. In most cases the issuing from the observation tube were then passed through hot reduced copper asbestos and copper oxide tos, and into a gas burette containing caustic potash solution, where the unabsorbed nitrogen is measured Tter of an hour. The weight of nitrogen is calculated after deduction of the amount contained in the the rate of which was uniformly 1,000 cubic centimetres per hour. The Ilford chromatic plate is the most suitable for taking photographic records. See Journal Chemical Society's Transactions, 1909, part 2, page No. 1243. £0 17 6 £1 10 0 £026 £0 18 0 £086 £076 £17 10 0 £1 13 0 £23 5 0 -i (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 679 BAIRD &TATLOCK (LONDON) LTD. 3624 3626 3624: Will's Gas-Measuring Burette, for use in estimating the stability of nitro-cellulose, graduated to 60 cubic centimetres, with large bore stopcocks, and Schellbach's enamelled band .. .. .. .. .. ... .. .. . . £1 10 ( (See W. Will, Zeits. fur Angew. Chem. 1901, 14 (31), 783.) Quotations for Will's Complete Apparatus, as used at Royal Gunpowder Factory, &c., on application. For complete description see the Journal of the Society of Chemical Industry, 30th June, 1902, p. 819. 3625 Glass Spirals, light, with tube ground in, for use with Will's apparatus for testing the stability of nitro-cellulose . . . . . . . . . . . . each £0 7 < 3626 Apparatus for testing Cordite (silvered vessel test): A. Bath, of copper, with seven copper pots, tubulure for regulator, water gauge, and tripod stand . . . . . . . . . . . . . . ..£55 B. Argand burner for gas, suitable for above . . . . . . . . ..£07 C. Paraffin burner with suitable screen for use with Bath A when gas is not available . . £0 12 D. Vacuum flasks, silvered, with side tube . . . . . . . . each £0 5 E. Thermometers, lens front, 75-85° C. in £° with red line at 80° C. . . £07 CROSS STREET • HATTOTST GARDEN, E-C 680 BAIR.D &TATLOCK (LOTSfDON) LTD. F. I.R. corks for fitting E in D . . . . . . . . . . . . . . £003 G. Gas regulator, Lowry's pattern (unfilled), made of Resistance glass . . . . £050 H. I.R. corks for fitting G in A . . . . . . ..£012 I. Felt discs for bottom of copper pots in A . . . . . . ..£003 J. Felt discs, split with hole in centre for tops of copper pots in A . . . . £004 K. Mouthpiece, suction, of glass with stopcock . . . . . . . . ..£019 L. Glass air reservoir, 50 cubic centimetres . . . . . . ..£016 M. Capillary metal tube for filling gas regulators G . . . . . . ..£020 N. Retort stand, sole 12 by 6 in., with 36 in. rod for supporting tubing connected to gas regulator G . . . . . . . . . . . . . . ..£046 0. Pipettes, glass, 10 cubic centimetres . . . . . . . . . . ..£006 P. Tubing, indiarubber, J in. bore, heavy walls . . . . . . per yard £0 111 Q. Tubing, metallic, copper flexible, J in. bore .. .. '.. „ £023 R. Connections for Q .. .. .. .. .. each, 2d. ; per doz. £0 1 10 3627 3629 3630 3627 Dr. Dupre's Heat Tester, as applied to explosives of the nitro-compound class (Explosives Act, 1875), and used in Government laboratories, consisting of tripod, copper cylinder with mica window, copper water bath with white japanned lid, in which are four holes, one for thermometer and three for test tubes . . . . . . . . . . . . £2150 3628 Argand Burner for Dr. Dupre's Heat Tester . . ..£086 3629 Test Tubes for use with above, special quality to comply with Government specification, of uniform capacity, with 3 marks . . . . . . . . . . . . per doz. £050 3630 Set of Strong Copper Sieves, with lid and bottom for cordite test . . £0150 3631s Heat Test Papers, answering " Home Office " specification . . per 1,000 in brown bottle £0 13 6 (1,000 smallest quantity supplied.) ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 681 nr s.,1 BAIBD dcTXTLOCK (LONDON) LTD. ,u A3631 A36311 Dupre's Constant Temperature Apparatus, with heavy copper boiler, etc., soldered joints for temperatures under 100° C. B3631T Dupre's Apparatus, as above, with heavy copper boiler and bulb condenser, etc. All joints brazed for temperatures 100° C. and over DESCRIPTION. This apparatus is for the purpose of maintaining a constant temperature, within very narrow limits, and can /be used for temperatures ranging roughly from 30° C. to 150° C. The principle employed is the constancy of the temperature of water boiling at a constant pressure. The apparatus consists of a boiler A, water jacketed bulb B, and reflux condenser c, connected as shown in illustration ; the whole being closed by a screw valve D ; this valve being the only opening to the air. The boiler A, which is about one quarter filled with water, is heated by a gas flame or other suitable means. When the water boils the air in the boiler is driven over into the bulb, creating therein a pressure varying in accord- ance with the amount of air originally in the apparatus. The steam generated being condensed and returned to the boiler does not affect the pressure in the bulb, and the vapour in the boiler will therefore remain at a constant temperature dependent on the said pressure in the bulb for any length of time desired. The actual adjustments are made as follows : — For temperatures below 100° C. The nozzle of the screw valve is connected with a vacuum pump, the valve opened and the apparatus exhausted so as to give a lower temperature than that required. The valve is then screwed down ; the cooling water (which passes first round the jacketed bulb and then through the condenser) is turned on and the boiler heated. A constant temperature is soon reached which can readily be raised to the point required by cautiously admitting air through the screw valve. The valve is then screwed down tightly, when the temperature will remain constant as long as heat is applied to the boiler, and unless the valve be unscrewed the apparatus will always maintain this temperature when used at any subsequent time. For temperatures above 100° C. The valve is opened so that the apparatus is filled with air at atmospheric pressure, and is then closed, the cooling water started, and the boiler heated as before. The temperature will now become constant at the highest safe point for which the apparatus is designed. The desired temperature is then obtained by cautiously allowing the necessary amount of air to escape by means of the screw valve. Without any special precautions as to gas regulation or nature of cooling water desired temperatures can be maintained within + 0.1° C. With an efficiently regulated gas supply and a supply of cooling water of constant temperature — such as that direct from a main — this apparatus can be designed to maintain desired temperatures within 0.001° C. for any length of time. The exact form of the boiler depends on the purpose for which the apparatus is required, the illustration showing the form of apparatus designed for heat test work. £6 15 £8 0 -CROSS STREET • HATTOTST GARDEN, E-C 682 BAIRD &TATLOCK. (LONDON) LTD. 3632 1632s Mill for Grinding Samples of Cordite, with gun-metal fittings, on wood sole, recessed for set of sieves No. 3630, improved pattern, as used at the Royal Arsenal, Woolwich . . £317 6 3633 3634 533s Mill, large pattern, with specially cut core for grinding hard cordite, and two heavy fly- wheels, as used at the Royal Gunpowder Factory, Woolwich Arsenal, Indian Cordite Factory, etc. . . J348 Mill for grinding cordite, large improved pattern, as supplied to the Royal Arsenal.Woolwich, fitted with double geared gun-metal wheels, brass hopper, two flywheels fitted with handles, on gun-metal carriage 5634 £13 10 0 Extra duplicate wheels of hardened steel to fit frame for mill No. 3634 each £20 £5 BAIRD &.TATLOCR (LONDON) LTD. 3635 3636 3635-3636 Aluminium Capsules or Basins, with glass cones to fit, for estimating the volatile matter in gun-cotton, used at Royal Gunpowder Factory, Waltham Abbey, etc. Aluminium basins . . . . . . . . . . each, 1 /3 ; per doz. £0 14 o Light glass cones lOd. ; £090 3637-3638 3639 3637s Cordite Cutter for cutting short lengths of cordite for analysis (Government pattern) . 3638s Brass Tray for receiving the cuttings (Government pattern) 3639s Kjeldahl's Apparatus, Allen and Moore's, consisting of brazed copper flask, 16 oz., tinned inside, Soxhlet tube, stopcock funnel, pure tin condensing tube, adapter flask and beaker £1 £1 1 0 £046 1 0 CROSS STREET • HATTCTNT GARDETST, E-C 684 BAIRD &TATLOCK (LONDON) LTD. Apparatus for the Estimation of Nitrogen MADE IN RESISTANCE GLASS. Owing to the high solubility of common glass in water containing ammonia, it is advisable to use for all apparatus designed for the estimation of nitrogen special glass free from this deficiency. On- xindermentioned articles, flasks as well as tubes, are therefore made of Resistance glass, which is well known as practically insoluble and for its high resistance against sudden changes of temperature. Flasks are stamped with R, tubes show blue lines. Both marks are registered. 3640 3641 3642 i 3640 Kjeldhal's Apparatus, consisting of 300 cubic centimetres conical flask, indiarubber cork, Resistance glass bent tube, and 200 cubic centimetres receiver . . . . each £046 : 3641 Nitrogen Apparatus, Kjeldahl-Wagner's. Complete apparatus, fitted with rubber stopper . . . . . . . . . . ..£053 i 3642 Nitrogen Apparatus, improved form. Complete apparatus, including rubber stopper . . £056 3643 3644 13 Nitrogen Apparatus, Stutzer's. Complete, with indiarubber stoppers . . £080 Nitrogen Apparatus, Threadwell's. Complete apparatus, with indiarubber stoppers . . £0160 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 635 BAIRD &TATLOCK (LONDON) LTD. 3645 3645 Kjeldahl's Apparatus for the determination of nitrogen, each set consisting of copper condenser on stand ; heating stand for distillation, with Bunsen burners ; heating stand for digestion flasks, with Bunsen burners ; complete with Resistance glass flasks for digestion 300 cubic centimetres, and conical flasks 300 cubic centimetres. For Price 3 631- 4 88/- 6 determinations. 120 /- per set. 3646 3646 Kjeldahl's Apparatus for the determination of nitrogen, with vertical condenser of copper, stand for distillation and for digestion, each fitted with set of Bunsens with stopcocks. Price, complete with conical Resistance glass flasks of 500 cubic centimetres capacity, and Resistance digestion flasks of 300 cubic centimetres capacity, with indiarubber stoppers, connecting tubes, etc. For . . 4 6 determinations. Price 73/6 94/6 126/6 each. CROSS STRET • HATTOTST GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. 3647 3647 Kjeldahl's Apparatus, for the estimation of nitrogen, modified form as devised by Dr. Plimmer, of the University College, London. Flasks of Jena glass, with burners, clamps, etc For • • 3 4 6 determinations. Price £3 17 6 £560 £7 10 0 3648 Apparatus for the determination of nitrogen, without water condensers, complete with Resistance glass flasks, 300 cubic centimetres and tubes, with- out digestion apparatus (see No. 3653). For Price 3 52/6 3648 68 /- 6 determinations. 95/- per set. 687 BAIRD &TXTLOCK. (LONDON) LTD. 3651 3649 3650 3649 Distillation Tubes, with two bulbs and trap, Resistance glass 3650 Distillation Tubes, with two bulbs and trap in top bulb, Resistance glass 3651 Distillation Tube, with one bulb and trap tube, Resistance glass each £026 £020 £0 1 9 3653 3654 3652s Distillation Bulb, improved form, designed by Mr. Watson Gray. (See description in the " American Chemical Society Journal of Industrial and Engineering Chemistry," Vol. I., page 802.) . . . . . . each £0 3653 Digestion Apparatus for nitrogen determinations, with set of Bunsen burners, each burner fitted with tap, complete, with 300 cubic centimetres Resistance glass flasks. For 3 4 6 flasks. Price .. 23/6 27/6 35/- 3654s Bruhl's Sublimation Apparatus, of nickel-plated brass. (See Berlin Ber., 1889, p. 238.) Height, 15 ; diameter, 15 centimetres. Price on tripod . . CROSS STREET • HATTOTST GARDETST, E-C 688 BAIRD &. TATLOCK: (LONDON) LTD. 3655 Size 5. Type I. Class AA. For very light Masses and Powders. (Fitted with two speeds.) 3655 Size 4. Type I. Class BS. (Fitted with three speeds.) Size 3. Type I. 3655 Class BB. (Machine taken to pieces.) Kneading and Mixing Machines, " Universal." Type I. j A feature of these small machines is the ease with which the various parts can be taken asunder. They are admirably suited to chemists' requirements, as well as for use in laboratories for the kneading and mixing of small s of light pill mass, pastilles, salve, powders, etc., or any material of consistency not greater than that of putty. tier wheel guards nor (in view of the facility with which they can be taken to pieces) tilting arrangement provided •<; small machines ; the latter can however be fitted, if desired, at extra cost, as below. J» Size No. 3 4 5 5 6 Class BB. BS. AA. BS. BS. Capacity (Measure) i£ pints \ gall. i gall. i gall. 2 gall. Capacity (by Weight) Putty-like Masses, about . . Ibs. i to 2 2 tO 4| 7 4i to 8J 6J to 15 Approximate dimensions overall : Length about . . . . inches 16 *9 20 20 ^5 Breadth about . . . . inches 16 24 24 28 3» Height about . . . . inches 14 17 .18 22 22 Price £500 £650 £6 17 6 £880 £10 15 0 Extra for tilting arrangement . . £090 £0 15 0 £0 15 0 £0 17 6 £150 I (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 689 BAIRD &TATLOCK CONDON) LTD. ,U 3657 3657 3657T Kneading and Mixing Machine, "Universal." (Bronze Model, Type N.) This is a small machine of a few ounces capacity, which is specially made for laboratory use. The trough is made in two parts and clamped together by a simple device, so that the machine can be easily taken to pieces for cleaning, and as everything with the exception of the base plate is made in bronze, the parts will not rust after washing out with water. A revolution counter is provided to indicate the number of revolutions of the blades, so that in making several experiments one can depend upon each set of materials being treated equally. The base plate carrying the whole machine is hinged to a hard wood base which is bored for screwing firmly to a table or bench, and by this means it can be turned right over for emptying. The greatest care is exercised in the manufacture, only the very best materials and workmanship being employed. A close grained bronze is used and the interior surfaces are accurately machined and polished, and the gears are machine cut. The interior trough dimensions are 3 by 2j by 2f in. and the blades are i J in. in diameter' £950 3658 3658s Ice Shaving Machine. The ice by this machine is reduced to fine shavings, machine is galvanised, diameter of mouth 5 in... .. ..£1160 CROSS STREET • HATTOTST GARDETST, E- C 690 BAIRD &TATLOCK (LONDON) LTD. Ball Mills for grinding samples of cement, clinker, emery, limestone, ores, salt, colours, chemicals, drugs, etc. These closed ball mills are suitable for grinding where a very fine product is required, and can bo worked her wet or dry. In mill, Fig. 3659, the material is fed into the opening after the cover plate shown on the side mill has been removed, and in mill, Fig. 3661, half of the drum is removed for filling and removing the ground iterial. The barrels of these mills are made of cast iron or steel as specified below, and the grinding is effected means of balls of hard forged special steel. The mills are supplied mounted on standards, 3660, or with bearing 23 for fixing to wood block or other support. Size No. i mills are constructed eilher for hand or belt drive. •i size for belt drive only. Power required, J h.p. for No. I and r h.p. for No. a. 3659 3660 359s Ball Mill, No. 1, Fig. 3659 or 3660, arranged for either hand or belt drive, with cast iron grinding barrel, igf by 5 J in. .. .. .. .. .. .. £17 15 0 3 ids Ball Mill, No. 2, as above, Fig. 3659 or 3660, for belt drive only, with cast iron driving barrel, 31$ by 6J in. . . . . . . . . . . . . . . . . £35 5 0 3661-3662 311s Ball Mill, No. 1, with cast steel grinding barrel, igf by 5j in., mounted on trestles, arranged for either hand or belt drive . . . . . . . . . . . . £21 5 0 Ball Mill, No. 2, as above, with cast steel grinding barrel, 31 J by 6J in., arranged for belt drive only . . . . . . . . . . . . . . . . £45 0 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 691 2 Y BAIRD & TATLOCK (LONDON) LTD. ... 3663 3663s Mill with inclined grinding barrel, igf by 9 in., for belt drive only (f h.p. required) . . £32 15 0 3665 Laboratory Mill, after Prof. Maercker, for grinding samples of food stuffs, grains, etc. 3664T Price to work by hand . . .... £14 5 0 36651 Price to work by power .. .. .. .. .. .. .. £U CROSS STREET • HATTOTST GARDETST, E-C 692 BAIRD &1ATLOCK (LONDON) LTD. 3666 3667 3668 ;66T Mill for crushing samples of sugar cane, rolls 5 by 4 in., weight if cwt., for fixing to post or block £6 10 0 s Analytical Grinding Mill, mounted on cast-iron stand, with brass-cut hopper, gun-metal bearings, wheel and pinion, and specially cut steel core and case, fly-wheel and handle . . £1010 0 - Grinding Mill, with clamp for table, and receptacle for holding ground material. Size No. . . . . . . . . . . . . i 2 Price .. .. .. .. .. .. 8/6 10/- ri 3669-3670 3671 269s Grinding Mill, for samples of malt, etc. Size No. 2A 270s Grinding Mill, for samples of malt, etc. Size No. 4 371s Mills, for grinding samples of barks, drugs, etc., with brass hopper. No. . . . . . . . . i 2 3 Capacity of hopper .... \ i 2 Ibs. Extreme height . . . . . . 13^ 17^ 22 inches. Price . 30/- 43/- 68/- each. £0 15 0 £100 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 693 BAIRD &TATLOCK (LONDON) LTD. • 3672 3673 36721 Analytical Mill, Seck's, lor use in crashing malt to a definite fixed degree of fineness or coarseness, as described by Dr. Saare of the Berlin Institute of Brewing in the Year-Book for 1901 of the Berlin Institute, p. 229 . . . . . . . . . . . . £13 3673T Analytical Mill, Seck's, as above, adapted for power The above mills are for analysis of coarse meal, according to the rules arranged by the Brewer's Testing and Training Institute, Berlin. The meal turned out is identical with that used in practice. It can be set accurately and at will, by a scale, for any degree of fineness. The meal is collected direct in the mash pot. Readily accessible and easy to clean, hence no losses through dispersion of dust. It consists of a pair of rollers enclosed in a hollow-cast casing. One of the rollers has fixed bearings, while the other is adjustable by means of an eccentric and a lever. The mill is worked in the ordinary way by a hand crank, the revolution being transmitted from one roller to the other by spur wheels. The meal produced falls into a mash pot, which, with its upper rim, makes a tight joint with the inner orifice of the roller casing, so that no meal dust can be dispersed through the joint. The opening in the frame casing through which access is afforded to the meal chamber is closed by a door, by opening which the mechanism for tightening down the joint on the rim of the pot is automatically released, so that the pot can be conveniently withdrawn. The adjustment of the degree of fineness of the meal is effected by a hand lever which can be shifted on a quadrant provided with a scale. When the index-hand of the lever stands at " o " the rollers are in contact with each other, while the extreme limit of displacement is marked with the figure 50. In order to obtain normal meal the lever should be set up at 25. The apparatus can easily be dismounted, as the top part of the casing can be turned back on a hinge ; similarly the cap-pieces of the bearings, which are held down by winged nuts, can easily be turned aside so that the rollers can be quickly removed at any time. DIRECTIONS FOR USING THE LABORATORY MILL. FOR COARSE MEAL. When about to use the crushing machine, first set it for the desired degree of fineness on the scale, by means of the hand lever, which should be fixed in position by tightening up the winged nuts. Then charge 50 grammes of the malt to be analysed, accurately weighed out into the feed-hopper above, while adjusting the feed-slide, preferably while simultaneously turning the crank by means of the thumb-screw, so that the grains can only just drop through the slot between the slide and the roller. Avoid opening the slide wider than necessary, because the malt will not be drawn so well into the rollers if a large quantity of malt has accumulated in the space between the rollers. Then turn the crank until the whole charge of malt has passed through the rollers, after this turn the mill a few times in the inverse direction in order that any particles of meal still clinging to the rollers may drop off. Open the hinged doors on both sides of the rollers and clean off any adhering particles of meal from the rollers by placing the brush supplied with the machine longitudinally first on one and then upon the other of the roller surfaces, and pressing it gently against it while once more turning the crank. After this, clean the inner slopes of the casing by passing the brush over them downwards. Now the door of the frame casing below may be opened and the mash pot removed. 10 £13 15 0 CROSS STREET • HATTCrtST GARDETST, E- C 694 ___ 3674 3674 (Section) 1.74' Malt Mill (small pattern) . . . . . . . . . . This Grist Mill has been introduced to supply a long-felt "want" in the laboratory, namely, a reliable mill ..•ing uniform grindings of any grade of grist, for precise analytical determinations, and embodied in it are the : lowing excellent points : — . Absolute uniformity of grinding at any grade, while the maximum of husk is retained. 2. The mill is practically air and dust proof, thus keeping grist free from atmospheric influences. v The mill is of metal construction throughout, with chilled steel grinding faces which are fluted in " opposition." 4. The grade of grist is mechanically indicated, thus giving standard results by whomsoever operated. 5. The varied and unreliable Coffee-mill grists, as at present generally used for malt analyses, are entirely perseded. 6. The mill is simplicity itself, there being no intricate working parts, and is very substantial and strong. £6 10 0 3675 i>75s Malt Crusher, with pestle, of cocus wood . . each £0 1 9 695 BAIRD &TATLOCK (LONDON) LTD. 3676 3676s Seck's Laboratory Mill, for grinding substances to very fine powder, all parts easily accessible, to work by power Dimensions. Revolutions Pulley Width Length. Width. Height. per minute. diameter. of pulley. 15 in. n.8 in. 20.7 in. 300 7.87 in. 1.57 in. THE "SECK" LABORATORY MILL FOR FINE GRIST (FLOUR). The need of a carefully constructed fine grist (flour) mill has been felt for a long time. Hitherto it has not been possible with mills of this category to produce material of the degree of fineness necessary for the determination of the nitrogen percentage in barley and for other similar processes. In addition to this fundamental defect, none of the mills hitherto used for this purpose were fitted with precision apparatus and scale, enabling correct regulation of the degree of fineness. Again, the cleaning of the working parts of the mill was generally a very troublesome and difficult performance. In a word, all fine flour laboratory mills now in use fail altogether to meet modern laboratory requirements. To supply the demand for an up-to-date mill, a model has been evolved which will remedy all prior defects. This mill has a cast-iron frame, which is divided into two parts. The lower half holds a fixed grinding-ring, while the upper half hinges on to the lower and supports the vertical mill-roller, the precision regulating apparatus, and the driving pulley shaft. Feeding is effected by means of a small hopper, which is closed down with a lid during working. The milled produce is collected in a glass which, by means of a wedge closure, is pressed up against an indiarubber ring surrounding the delivery opening. This arrangement prevents the loss of any flour during grinding. The degree of fineness is regulated by turning a small hand-wheel connected with the vertical roller. The latter is kept in position by means of a tightening screw with spanner movement. The upper part of the hand-wheel is provided with a scale marked o° to 50°. The pointer is fixed on the frame. The grinding rollers are fluted and similar in make to those of coffee mills, but differ from the latter in that the flutings are of smaller dimensions at the bottom of the rollers than at the top. This device has the effect of gradually decreasing the passage through which the produce passes, which therefore gets finer and finer as it passes from the top of the roller to the bottom. The degree of fineness can be regulated so as to effect complete pulverisation, giving a product for containing 98 per cent, of flour. The grinding rollers are of the best cast steel and extremely tough. The wear and tear of the rollers will not be apparent until the mill has been in use for many years. Even then, the scale can be readjusted, since the pointer affixed to the frame can be displaced so that the maximum degree of fineness coincides with o°. The hopper of the mill takes 100 grams (of barley). After use, the mill can be easily cleaned by hinging back the upper part of the frame and removing all traces of powder with the brush, which is provided with each mill. The flour brushed down falls into the glass receiver so that the produce after milling weighs exactly the same as before. The mill has a horizontal driving shaft fitted with fast and loose pulleys. After grinding is finished the belt can be pushed on to the loose pulley and the frame can be opened without removing the belt from the machine. The careful construction and the ease and exactitude with which it works are the chief features of this mill. The power required is nominal £15 15 0 CROSS STREET • HATTON GARDE1ST, E-C 696 BAIRD &.TATLOCK (LONDON) LTD. Fig. I Fig. 2. 3677 i Fig- 3- Fig. 4- 3677 Fig. 5- >77T Machine, devised by Capt. Sankey, for rapidly testing Steel and other Metals, intended for technical use . . . . . . . . . . £20 0 0 Owing to the large amount of information gathered during many years, in connection with Ihe tensile tests lich have been used for exhibiting the properties of steel and other materials, such as brass and bronzes, employed • mechanical engineers, it is usual to specify that test, and it is relied on in cases of dispute. At the same ne, a tensile test is not deemed reliable if made on specimens smaller than £-inch diameter, with, an overall igth about 6 inches, so that a comparatively large piece of steel or other metal, involving considerable expense machining, has to be prepared, and a testing machine of a pulling capacity of not less than 30 tons is necessary. :ch machines are costly, and, moreover, require an expert to work them, and only large works are able to afford is outlay, therefore the small user must have recourse to testing works, involving considerable expense and 'lay. The practical result — to a great extent — is that tensile tests are only made when definitely specified as -rt of the contract, or in case of dispute, and are not used when the user is accepting material that he has rchased. He therefore relies on the statements of the suppliers of the material. There is, consequently, a cl:ld in workshop practice for a simple test which can be rapidly carried out, can be relied upon, and requires • ly a small amount of material and a test piece of simple form. For many years a simple bending test has been in use in workshops, the measure of the quality of the material ing the degree of bending withstood before fracture, the resistance to bending, and the appearance of the icture. Personal experience is required for this test, and results do not lend themselves to be stated in definite ures ; it is, therefore, not possible to use this test as a criterion when buying, or selling. If a machine, however, > ;re so constructed as to record automatically the degree of bending, as well as the resistance to bending, the rsonal element would be removed, and such a machine could be used for the above purpose. The machine described fulfils these conditions, and it provides a simple and inexpensive, but at the same ne absolutely reliable, shop test of the materials, such as steel, brass and bronze, used by engineers. The st pieces are $-inch diameter and 4 inches long, consequently they are inexpensive to make, and can often be got t of even a finished piece of work without injury to the piece. The test itself takes about one minute, and e result is automatically plotted, by the machine, on a strip of paper. This record shows the number of bends, e bending effort of each bend (measured in pound-feet) .and the total energy (in foot-pounds) required to break • :e test piece. This record can be examined at leisure by a competent person, but the actual test can be per- rmed by an intelligent labourer. It is to be noted that the appearance of the fracture obtained helps considerably : determining the value of the material ; some little experience, however, is needed before a true judgment can ' formed, and it is difficult to give a description of these fractures that will really convey a true idea of their ; pearance. The best plan is to retain examples of the fractures of suitable and unsuitable steels, etc., for the ; rpose of compaiison. Fig. i is the machine ; Fig. 2 shows an unbroken and a broken test piece ; and Figs. 3, 4 and 5 are reduced csimiles of some records. A Pamphlet giving full particulars of the machine, and of the results obtained with it, will be sent on application. I CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS.Jf 697 ear BAIRD &.TATLOCK (LONDON) LTD 3678 3679 3678* 36791 Machine, to work by power, for polishing and preparing the surface of metal intended for microscopical examination. The machine is of simple design, and the polishing table runs on an adjustable bearing footstep. Price, including set of six blocks, rings, and polishing materials Machine, similar to above but to work by hand. The revolving table is mounted upon an adjustable ball-bearing footstep, and runs practically noiseless. Water vessel, loose water guard, and drain pipe. Price, including box containing six polishing blocks, with brass rings and polishing powders £2 10 £4 14- -CROSS STREET • HATTON GARDEN, EC 698 BAIRD &TATLOCK (LONDON) LTD. 3680 36801 Combined Power and Hand Saw, for cutting sections of metals, minerals, and rocks for microscopical examination. It is provided with a swivel vice which can be set up to saw. The connecting rod is easily disconnected for hand flower . . . . . . £1 15 0 3681 681T Machine for polishing and preparing the surface metal intended for microscopical examina- tion, to work by treadle. The machine is provided with table, two drawers, set cf blocks, rings, chucks, and polishing material £8 10 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 699 BAIRD &TATLOCK (LONDON) LTD. 36821 3682 3683 Mechanically Operated Agate Mortar, 4 in. diameter, with pestle, for reducing ores for assaying purposes This machine is of new design, and requires no attention. It works automatically, producing work of the greatest uniformity and fineness. The motions of the machine are identical with those given to the pestle when working by hand, and in. addition the mortar is made to rotate with the table to which it is attached. 3683T End Runner Mill, Size No. 1, for hand power. Size of mortar, 10 by 4 in. deep, approximate weight of mill fitted with iron mortar and runner, I cwt., size of base, I5i- by 9 in., speed 90-120 revolutions £10 10 3684 36841 End Runner Mill, Size No. 0, for hand power. Size of mortar, 10 in. diameter by 4 in. deep . . £50 CROSS STREET • HATTON GARDETST, E-C 700 BAIRD &TATLOCK (LONDON) LTD. 3685 H$5S Opacity Meter, designed by Mr. Chapman Jones Description on application. Filter Pumps or Aspirators. £5 15 0 3691 3686 3688 3689 3690 86 Filter Pump, glass, Arzberger & Zulkowsky's, on board, with two stopcocks 87 Filter Pump, glass, Bunsen's, on polished board, one stopcock : 88 Filter Pump, or aspirator, of glass, giving with high-water pressure an almost perfect vacuum 89 Filter Pump, or aspirator, of brass, giving almost similar results, all carefully tested 90 Filter Pump, brass, without gauge. . 91 Filter Pump, brass, with gauge 92s Filter Pump, brass, Korting's make, as Fig. 3693 but without gauge £0 12 6 £080 £030 £043 £086 £0 18 6 £0 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 701 tiX*t< BAIRD &TATLOCK. (LONDON) LTD. 3693 3693s Filter Pump,, brass, Korting's make, with gauge £1 10 3694s Dr. Starkey's Water Pump, fatted with automatic valve and gauge, so made that in the event of the water being suddenly turned off, the valve comes into play and prevents the water from going back into the flask .. .. .. .. .. ..£1 "^ -53 3695 3697 3698 3695 Filter Pump, glass, as used at University College, King's College, Institute of Chemistry, etc. 3696 Filter Pump, glass, on board, for blowing and exhausting. For both, connect (D) with the vessel to exhaust, and (G) with the blowpipe. For blast only, leave (D) and (c) open. The water pressure can be regulated by a clip and rubber tubing fitted on (D) . . 3697 Filter Pump, glass, improved pattern, with two side tubes, one of which can be fitted to gauge, or both can be used for a double exhaust, water inlet at lower side tube 3698 Filter Pump, Fischer's, without stopcock 3699 Filter Pump, Fischer's, with two stopcocks £1 1 CROSS STREET - HATTCTN GARDEN, E*C 702 BAIRD &. TATLOCK (LOM)ON) LTD. * •=BB WATER INLET1 a\a 3700 3701 WATER OUTLET 3702 WATER OUTLET 3703 '00 Filter Pump, glass, new form, with tubes for exhausting two vessels, or one vessel and connection to gauge. The water supply is connected to tube marked A . . . . £056 '01 Bourdon Vacuum Gauges, 2j in. diameter, with adapter fitted for indiarabber tubing .. £0 12 6 ''02 Water Blast Pump, air blast, gauge tube, and water regulating stopcock, bronzed zinc water jacket, brass parts polished and nickel-plated, with dissectable pump, and adjust- able lower cones .... £160 '03 Water Blast, as above, with metal gauge and silvei -plated scale DESCRIPTION OF PUMP. The apparatus consists mainly of three parts, the reservoir (A), the pump (B), and the stopcock (K). The nut joins the pump (B) to (A), whilst the tube a a is connected to the water supply pipe. On the top of (A) is the pcock (F) with nozzle for the escape of the compressed air. Stopcock (K) regulates the outlet of the water. side the reservoir an almost complete separation of air from water takes place. The apparatus is worked in the following manner : — The tube (D) of the pump is screwed into (B) as far as ssible, the stopcock (F) closed, (K) opened, and the water turned on. (D) is now screwed down again by turning round its axis until the gauge connected with (B) indicates the maximum of suction power. For use as blower, ; gauge is unscrewed, and stopcock b turned full on, the stopcock (F) opened, and the run of the water so regulated means of (K) that it escapes almost free from air, and has a fairly constant level in the cylinder (A). A blast of equal to 22 centimetres mercury pressure is thus obtained under a water pressure of 2 to 3 atmospheres. On sing water supply tap, to prevent any water being forced up, tap {K\ must be closed gently. With water pressure 2 to 3 atmospheres and a supply of water of 9 to 10 litres per minute, the apparatus sucks up to to 20 litres ( air, and gives in a short time almost a vacuum. £220 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 703 BAIRD &TATLOCK (LONDON) LTD. 3704 3705 3704T Raplin Hand Ice -Making Machine, including vessel for making block ice . . . . £1010 A. Spare Carafes .. .. .. .. .. .. .. each £0 2 Air Pump Receivers. See Bell Jars with knobs and stoppered, Nos. 1991-2000. 3705 Air Pump, Tate's exhausting and condensing, diameter of brass plate 7 in., barrel 16 by ii in., on iron base 3706 Air Pump, Tate's as above, diameter of brass plate 8£ in., with mercury gauge . . £4 15 3707-3708 3709-3710 3707 Air Pump, brass barrel 8 by ii in., brass plate 5f in., on polished mahogany sole 3708 Air Pump, brass barrel 8 by i£ in., brass plate 7 in., on polished mahogany sole . . 3709 Exhausting Syringe, Brass. A B Length of cylinder . . . . . . . 5 7 £1 17 £2 5 C 8 in. Diameter Price 3710 Condensing Syringe, Brass. Length of cylinder Diameter Price A 5 11/6 B 7 11/6 15/- C 8 in. ^2 »» IS/- CROSS STREET • HATTON GARDETST, E- C 704 *pl BAIRD &TXTLOCK (LONDON) LTD. 3711 (711 Exhausting and Condensing Syringe. Brass. Length of cylinder Diameter Price A B C 5 7 8 in. i I* ij,, 11/6 16/- 17/6 3712 3716 712 Air Pump Plate, of brass, mounted on iron tripod sole, with stopcock and side tube for connecting it with an aspirator or Geryk pump. Diameter of plate . . . . . . . . 7 8} 10 in. £1 12 6 £220 £2 12 6 713 Price, with gauge plate and mercury gauge, 15/- extra (bell jars extra, see Nos. 1991-2000). S714 Air Pump, double barrel, mahogany stand, brass plate 7 in. Similar to Fig. 3716, but plate not mounted on pillars 715 Air Pump, double barrel, mahogany stand, brass plate 8i in. Similar to Fig. 3716, but plate not mounted on pillars £550 £650 $716 Air Pump, double barrel, mahogany stand, brass plate 10 in., with mercury gauge and stopcock, best finish . . . . . . . . . . . . . . ..£1100 SMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 705 BAIR.D &TATLOCK (LONDON) LTD. "Geryk" Patent Vacuum Pumps. INTRODUCTION. The " Geryk " Vacuum Pump is now so well known that it is unnecessary to enlarge upon its merits. It combines the advantages of great simplicity with the power of obtaining a very high vacuum. It can be made in any sizes up to 100 or more cubic feet capacity per minute. The larger pumps give a vacuum in every respect equal to that obtained by the smaller pumps. Its uniform efficiency is not impaired by constant running. Section of Barrel. DESCRIPTION. A. Suction Pipe. B. Air port into cylinder above piston. C. Piston bucket leather, an easy fit in cylinder, and kept up to walls of cylinder by pressure of oil in annular space (D). E. Piston valve which moves when commencing to exhaust only, and is quite inactive when vacuum is within about J in. F. Air pipe to relieve piston on first few strokes. G. A collar through which piston rod passes fieely. I. A hydraulic collar to make joint with piston rod, the flange or face of which covers joint of (G) with cover (H), thus forming a frictionless equivalent of a stuffing-box and a delivery valve combined. When piston is at bottom of stroke there is a perfectly free opening from (A) to (B). As the piston rises the port (B) is cut off and the cylinder full of air irresistibly carried up to the outlet valve (G). No air can by any possibility get back past the piston as it is covered with oil. As the piston continues to rise and the pressure upon it increases, so the bucket leather is forced more tightly against the walls of the cylinder. CROSS STREET • HATTQN GARDEN, E-C 706 BAIRD &L TXTLOCK (LONDON) LTD. Whatever oil gets below the piston is immediately picked up through the valve (E), when the piston gets to e bottom of its stroke again. When the piston is at the top of its stroke it is in contact with the valve (o), d lifts (G) J in. off its face, giving a free outlet for the air. But there is so much oil on the piston that a con- lerable quantity of it is forced through the valve at (G), driving all air before it. While the piston is at top of •oke the valve cannot close, and the oil at (j) and (K) becomes for the time being all one body, so that no air can ssibly return although the valve is fully open. As the valve (G) is resting on the piston it cannot close until e piston has made J in. of its descent, and consequently oil equal to J in. in depth will have entered the cylinder ady to be discharged behind the air upon the next upstroke. With a single-cylinder pump a vacuum within J of a millimetre can readily be obtained. With a double-cylinder mp in series, i.e.. with the second barrel exhausting from the first, a very much higher vacuum can be pro- ed. With a good drying tube, a vacuum with iither rough or very refined, and are used in many of the principal laboratories in this country. They are self- ubricating, free from leakage or breakdown, even when subjected to rough treatment, and can be supplied lirect-couplod to electric motor. $728T Size o. Speed, 800 revs, per minute ; capacity, 7 cubic ft. per minute ; horse-power, i . . S7291 Size I „ 600 „ „ „ 14 „ „ „ 2 . . 1730T Size 2 ,, 500 ,, „ „ 27 „ „ „ 4 . . •7311 Size 3 ,, 400 ,, „ „ 42 „ „ „ 6 . . £30 0 £43 10 £54 0 £65 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 709 BAIRD &. TATLOCKL (LONDON) LTD. 3732 3733-3734 3736 3732 Aspirator, simple form, made in copper, with 2 stopcocks and tubulure for thermometer. 5 litres. 10 litres. £140 £1 10 0 3733 Aspirator, double, Muencke's (Dingler's Polytechnickes Journal, 1884, 251, 219 ff.). Affords an uninterrupted exhaustion, by rotatoiy movement. Reservoirs of copper, each holding about 5 litres 3734 Aspirator, double, as above. Reservoirs of copper, each holding 10 litres 3736 Aspirator, reversible, with double glass reservoirs, each graduated to 5 litres, mounted on iron standards on polished mahoganv base 3737 3737 Photographic Dishes, shallow, white glazed. 5 by 4 7 by 5 8 by 6 9 by 7 10 by 8 u by 9 in. 9d. lid. I/- 1/3 1/6 21- each. 12 by 10 13 by n 14 by n 16 by 12 18 by 14 20 by 16 in. 2/6 3/3 4/6 7/- 9/6 16/- each. 14- • CROSS STREET • HATTOTST GARDEN, E-C 710 BAIRD &TATLOCK (LONDON) LTD. 3738 3739 3740 3738 Developing Dish, patent form, with well or cistern. In introducing this article, as shown in the accompanying illustration, a great advantage is offered to the operator, for, as will be seen, the well at the right hand end of the dish is of such a form as to hold sufficient developer to develop about one dozen plates of the particular size (quarter plate, 5 by 4 in., half plate, and whole plate) for which the dish is made. When the operator is ready, the amount of developer is placed in the well, and the plate placed in its position. By tilting the dish the developer is then flooded over the plate, continuing this until the plate is developed. The developer is then allowed to flow into the well, the plate remaining free of the developer, so enabling the operator to take out the plate without staining the fingers as in the old method. Another advantage is that when the operator is not actually developing the plates, there is tess air surface operating on the developer in the well, thus avoiding decomposition. Quarter Special Size, Half plate Whole plate. 5 by 4 in. and 7 by 5 in. plate. 1/6 2/- 2/6 3/6 3739 Photographic Dishes, deep, white glazed stoneware. 5 by 4 7 by 5 8 by 6 10 by 8 12 by 10 lOd. I/- 1 1/2 1/8 2/9 3740 Photographic Dishes, best quality enamelled steel. Quarter plate 5 by 4 in. Half plate. lOd. I/- 1/4 12 by 10 15 by 12 18 by 12 4/6 7/- 8/6 16 by 12 8/6 Whole plate. 2/3 20 by 16 14/6 18 by 14 11/6 20 by 16 in. 18/6 each. in. each. 10 by 8 3/- 24 by 18 in. 23/- each. 3741 3742 3741 Perforated Weight, white glazed, for developing films in lengths 3742 Porcelain Drainer, white glazed, for photographic plates. A. Suitable up to half plate size B. Suitable up to whole plate size each £0 1 0 each £009 £0 1 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 711 BAIRD &1ATLOCK (LONDON) LTD. 3743 3744 3743 Standard Developer, new pattern, white glazed stoneware, with cover. A diluted developer is put in the trough, one plate after another is inserted between the grooves, and the plates left to develop. Quarter plate. Half plate. 4/6 5/6 each. 3744 Porcelain Photographic Plate Washer, white glazed. For Quarter plate 3745 Pipettes, plain, without mark. Capacity about Price Half plate Whole pkte. 7/- each. 25 50 IOO C.C. 3d. 4d. 6d. each. 2/9 3/9 5/6 per doz. E" ~^Hfcx 3746 3747-3748 3749 3746 Pneumatic Troughs, with side ledge and movable shelf, white japanned iaside, black outside. A. Length 10 in., width 7f in., depth 4! in. . . B. „ 14 „ „ 9| „ ,, 6| C. ,, iyi „ ,, i2j ,, 7! ,, . .' D. „ 24 „ „ 14 „ „ 8J „ . . / 3747 Pneumatic Trough, round stoneware, diameter n by 5 in. deep 3748 Pneumatic Trough, round stoneware, diameter 10 by 4 in. deep £0 4 £0 6 £0 8 £0 11 £0 £0 2 2 3749 Pneumatic Trough, rectangular, of heavy clear glass. 8 by 4 by 4 12 by 6 by 6 31- 8/6 14 by 7 by 7 in. 14/- t CROSS STREET • HATTCTrST GARDETST, E- C 712 BAIRD &TATLOCK (LOM)ON) LTD. 3750 3751 3752 •750 Beehive Shelves, stoneware. Diameter Price 3 6d. 5/6 1751 Beehive Shelves, glass . . 5752 Pneumatic Troughs, clear glass round, extra strong. Size . . . . 6 by 4 8 by 4 10 by 5 Price .. .. I/- 1/3 2/6 3753 4 in. 7d. each. 6/9 per doz. 3 by if in., lid. ; 3? by 2j in., 1/1 12 by 5 3/6 14 by 6 in. 5/- each. (753 Pneumatic Trough for Mercury, in strong glass, for vertical tube experiments, widened at top. Height . . . . . . • . . . . 7 8J 12 in. Diameter at top . . . . • • 5i 4 4 .. Diameter of cylinder . . li 2 2 ,, Price .. .. .. .. ..3/6 1/9 2/- each. 3754 ?754' Small Laboratory Press, with porcelain basin and plate for use in pressing where it is essential that the zinc does not come in contact with metal of any sort. Small size Large size £1 17 £3 17 BAIRD &TATLOCK (LONDON) LTD. 3755 3756 3755s Tincture Press, with enamelled cylinder and tin can, mounted on stand with wrought iron uprights. Size Diameter Capacity Price 3756s Tincture Press with enamelled cylinder and tin can with base to screw to table. Size . . . . . . i 2 3 Diameter . . . . . . 5^ 6J 7\ Capacity ...... 4| 6f Price .. .. .. 25/6 32/6 41 /- I si 3* 281- 2 6 6 32/- 3 9i 36/- 4 8J in. 15 pints, 40/- 32 pints. 95/- each 3757-3758 3759 3760 3761 3757 Mercury Troughs, German porcelain, to hold 8 Ibs. mercury 3758 Mercury Troughs, German porcelain, to hold 16 Ibs. mercury 3759 Mercury Troughs, German porcelain, to hold 4 Ibs. mercury 3760 Glass Bulbs, filled with hydrogen and chlorine gas to explode and illustrate combination of H and Cl on exposure to bright light . . each 3761 Anderson's Potash Bulb. (See Journal of the Society of Chemical Industry, No. 2, vol. xviii., p. 119) 3762 Potash Bulb, by M. Gomberg. (See Journal of the American Chemical Society, vol. xviii., No. n.) 3762 £0 2 £0 4 £0 1 £0 2 £0 3 £0 3 CROSS STREET • HATTOTST GARDETST, E-C 714 BAIRD &L TATLOCK. (LONDON) LTD. 3763 3764 3765 763 Liebig's Potash Bulbs. Improved by Professor Dittmar 764 Potash Bulbs, Liebig's 765 Potash Bulbs, Mohr's 766 Potash Bulbs, Mohr's, with calcium chloride tube, ground to fit 3768 3769 3767 '67 Potash Bulbs, new form . . . . . . . . . . . . . . each £020 768 Potash Bulb, new and improved form, designed by Arthur Edwin Hill each, 3/- ; perdoz. £1 15 0 '69 Potash Bulbs, Mohr's, with calcium chloride tube . . . . . . each £020 3770 3771 3772 '70 Potash Bulb, new pattern, with calcium chloride tube, 4^ by Jin. inside ground to fit .. £026 71 Potash Bulbs, Ure's . . . . . . . . . . each £013 ^72 Potash Bulbs, Delisle, with aluminium foot, 10 grammes in weight .. .. £036 715 BAIRD &TATLOCK. (LONDON) LTD. 3773 3773 Porcelain Boats for combustion, of Meissen ware. Length .. 45 60 75 75 Width .. 12 10 ii 15 Price . . 6d. 6d. 6d. 7d. 5/6 5/6 5/6 6/6 3774 Pulse Glass 3774 100 no "5 145 mm. 18 10 13 28 „ 8d. 8d. 9d. 1/1 each. 7/6 7/6 8/6 12/6 per doz. £0 1 3775T Boats for combustions, fireclay. Length External diameter Price 3775 5 f 2/6 5 f 2/6 3 i 2/6 3 \ 2/6 per doz. Models of Pumps, 3776 3777 3778 3776 Pump Model, glass, suction or lift pump . . 3777 Pump Model, glass, suction or lift pump, on stand with cistern 3778 Pump Model, glass, suction and force pump 3779 Pump Model, glass, suction and force pump, on stand with cistern CROSS STREET • HATTOTST GARDETST, E-C 716 BAIRD ^TATLOCK (LONDON) LTD. 3780 3781 3780 Pump Model, glass, fire or force pump, single 3781 Pump Model, glass, fire or force pump, on stand with cistern 3782 Pump Model, glass, fire or force pump, double 3783 3784 3785 3783 Pump Model, glass, double fire or force, on stand with cistern 3784 Lift Pump, glass, mounted on wooden stand with metal trough 3785 Force Pump „ 3786 Bramah Press, on wooden stand with metal trough 8782 £026 £080 £056 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 717 3787 3788 3787 Press, hydraulic or Bramah press, without stand 3788 Press, hydraulic or Bramah press, on iron stand 3789 Bladder Glass for air pump experiments, with I.R. sheet 3790 Ram, model of, in glass 3789 3790 3791 3791 Retorts, best Bohemian glass, well annealed. 3792 Capacity 60 125 250 350 500 625 750 c.c. Price 3d. 4d. 5d. 6d, 7d. 7d. 8d. each. ii 2/9 3/6 4/6 5/6 6/6 6/9 7/6 per doz Capacity i i£ 2 2i 3 4 5 litres. Price 9d. I/. 1/2 1/3 1/6 1/8 2/- each. ,, 8/3 ll/- 13/- 14/- 211- 231- per doz. 3792 Retorts, best Bohemian glass, Capacity . . 60 with tubulure 125 for thermometer and 250 350 filling, 500 well annealed. 625 750 c.c. Price 4d. 5d. 6d. 7d. 8d. 8d. 9d. each. „ 3/6 4/6 5/6 6/6 7/6 7/9 8/6 per doz. Capacity Price -o"*4^ - i lOd. 91- I* 1/2 131- 2 1/4 15/- -^S£Sf» 1/9 20/- a 3 23/- 4 2/3 261- 5 2/6 29/- litres, each, per doz. |y 14 • CROSS STREET • HATTOTST • - — ^~* •• GARDEN, E-C-HM 718 i BAIRD &.TATLOCK (LONDON) LTD. 3793 3794 793 Retorts, best Bohemian glass, stoppered, well annealed. . Capacity Price Capacity Price 794T Retorts without tubulure and stopper, new Jena Glass. Capacity . . 50 100 250 500 750 1000 1500 2000 c.c. Price .. 3d. 4d. 6d. 9d. lid. I/- 1/3 1/6 each. 2/9 3/6 5/2 8/3 9/9 ll/- 13/9 16/3 per doz. 60 125 250 350 500 625 750 c.c. 5d. 6d. 7d. 10d. lid. 1/1 1/1 each. 4/9 5/9 6/9. »/- 10/6 12/- 12/6 per doz. I li 2 2j 3 4 5 litres. 1/3 1/9 2/- 2/3 2/9 3/- 3/2 each. 14/- 18/6 at/- 26/- 321- 35/- 36/- per doz. 3795 795T Retorts, with tubulure and stopper, new Jena glass. Capacity . . 50 100 250 500 Price .. 10d. lid. 1/2 1/8 750 1000 2/2 3796 1500 2/5 20OO C.C. 2/10 each. 9/6 10/3 13/3 19/3 22/3 24/- 27/- 32/6 per doz. 796T Retorts, with tubulure but without stopper, new Jena glass. Capacity . . 50 100 250 500 756 Price .. 5d. 6d. 8d. 1/1 1/3 4/6 5/3 7/6 12/- 14/- 1000 1/4 15/- 1500 1/8 18/9 2000 C.C. 2/1 each. 23/- per doz. 1 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 719 3797 Retorts, Resistance glass, well annealed and carefully made, with tubulure, specially suitable for the distillation of benzole, naphtha, etc. Capacity . . . . • • . . 100 150 200 250 c.c. Price . . 5/- 5/6 6/- 7/6 per doz . . 58/- 64/- 70/- 88/- per gr 3798 3799 3800 3798 Dr. Paul's Apparatus of Porcelain for melting, distilling, and subliming. No. ...... 2 4 6 Capacity . . . . . . 200 500 1000 grammes. Price . . . . . . 3/- 4/6 6/6 each. 3799 Retorts, copper, for oxygen, brazed, tube 10 by 2 in., fitted with cork and glass tube 3800 Retorts, copper, brazed, with brass cap, clamped on top, and brass leading tube 3801 3801 Retort, sheet iron, for oxygen 3802 £056 3802 Iron Retorts, for mercury distillation with swing clamping screws. Capacity . . . . . . . . . . i 2 Price .. .. .. 10/6 18/- 4 pints. 22/- each. CROSS STREET • HATTOTST GARDETST, E-C BAIR-D &TATLOCK (LOM)ON) LTD. 3803 31 3 Iron Retorts for mercury distillation, with swing clamping screws and condenser. 2 4 pints. 30/- 40/- each. 4 3804 Retorts, fireclay. Capacity Price, plain stoppered I/- 1/3 3805 I 1/6 2/- 2/6 2 3 3/- 3/9 3/6 4/3 3806 4 4/6 3*6 Retorts, Resistance glass, with receiver ground to fit, both stoppered. Capacity . . . . . . . . . . 2 4 Price .. .. .. .. ..1/6 21- 8 pints. 6/6 8 oz. 2/6 each. .^- — J —. --I br 3810 V^^^f^jjj^V 3811 3807 3808 Receivers for Retorts, best Bohemian glass. 587 Plain .. 250 5d. 500 7d. 750 c.c. 8d. i 9d. ii litres. I/- each. 13 * Tubulated 6d. 8d. 9d. lOd. 1/2 .. '8 • Stoppered 9d,. l/- 1/2 1/3 1/9 „ 18 1 With two necks . . 8d. lOd. 1/1 1/3 1/6 „ . With three necks irf*S\= — esra*-72^ssa 1/2 s&fzss- 1/4 1/7 1/8 */ ™ it ^r^ [^CHEMICAL AND SCIENTIFIC^APPARATUS AND PURE CHEMICALS.n - 721 BAIRD &TATLOCK: (LONDON) LTD. -rO 3813 3812 3814 3812 Mercury Distillation Apparatus, mounted on board for fixing to wall, with ring, burner, and asbestos lined iron hood for covering bulb • • • • • • £2 15 3813 Apparatus to purify mercury by dropping through nitric acid, complete with stand and clamp 3814 Apparatus for the distillation of mercury in a vacuum, by Prof. W. R. Dunstan and T. S. Dymond, complete with stand, burner, clamps, etc. . . . . . . £1 17 (See Philosophical Magazine, April, 1890, p. 367.) CROSS STREET • HATTQTST GARDEN, E'C- 722 BAIRD &.TATLOCK (LONDON) LTD. 3815 3816 3817 3815 Receivers or distilling bulbs, with ground-in tubes bent at an angle, tubulure for thermometer, etc. } I 2 3 4 litres- Price . . 3/3 4/- 5/- 6/6 7/6 each. 3816 Rupert Drops 3817 Bologna Vials . . per doz. £006 £020 3818 3818 Spatulas, steel, with balanced cocus wood handles, rivetted. Length of blade Price 3* 7d. 6/6 4 7d. 6/9 3819 3819 Spatulas, steel, narrow blade, balanced handles 4^ 5 6 8 10 12 in. 9d. 9d. lOd. 1/4 2/2 3/3 each 8/6 8/9 9/6 15/6 25/- 38/- per doz. 4 in. lOd. ; 5 in. l/- 3820 3820 Spatulas, horn. Length Price » • • • 3821 Spatulas, flexible horn. Length Price 3J 3d. 2/6 4* 3d. 2/9 3i 3d. 2/6 3821 6 5d. 4/6 4 4d. 3/9 8 7d. 6/9 6 6d. 5/6 ioj in. 1/2 each. 13/- per doz. 8 in. lOd. each. 9/- per doz. CHEMICAL AND SCIENTIFIC APEkRATUS AND PURE CHEMICALS. BAIRD &.TATLOCK (LONDON) LTD. 3822 3823 3822 Horn Spatulas, thin, suitable for microscopic work, 4$ in. 3823 Horn Spatulas, with spoon end, 6J in. 3824 Spatulas, of German silver, with wooden handle. Total length Price 3824 each 4d. ; per doz. £0 3 each 6d. ; per doz. £0 5 6 1/3 8 in. 1/6 each. 3825 3825 Spatulas, pocket, horn, folding 3826 Spatulas, pocket, steel, folding, bone handle 3826 each £0 £0 3827 3827 Spatulas, vulcanite. Length Price „ 38281 Spatulas, platinum. See Nos. 2357-2359. 3829 Spatulas, glass, small ?830 Spatulas, bone. Length Price 5 4d. 3/9 3* 1/6 6 4d. 3/9 3829 7 5d. 4/6 4 2/9 8 5d. 4/9 10 m. 8d. each. 7/6 per doz. each 4/- per doz. 3831 3831 Spatulas, pure nickel, 3 in. 3832 Spatulas, pure nickel, with spoon on end, 4f in. 3832 each 8d. ; per doz. £0 7 each £0 1 CROSS STREET • HATTCnST GARDEN, E- C 724 BAIRD &.1ATLOCK (LONDON) LTD. 3833 3834 3833 Spatulas, nickel, 3 in. blade with bone handle, total length 5} in. 3834 Spatulas, Royal Berlin porcelain. Length . . ... Price 3835 Spatulas, porcelain, German. Length Price 3835 each, 1/6; perdoz. £0 17 0 4i 6 8 12 in. • • I/- 1/3 2/- 3/- each. 4 5 6 8 9 10 in. 5d. 6d. 8d. lOd. I/- 1/4 each. 3836 3837 3836 Scoops, horn. Length Price 3837 Horn Scrapers, specially adapted for cleaning mortars, etc Length Price 3838 Scoops, aluminium, as Fig. 3836. Length Price 3839 2| 3i 41 6 in. 4d. 5d. 6d. 8d. each. 3/- 4/- 5/6 7/6 perdoz. rs, etc. 2| 3i 4l in. 4d. 6d. 9d. each. 9 10 12 centimetres. I/- 1/3 1/6 each. 11/6 14/6 17/6 per doz. 3839 Scissors per pair, 5$ in., I/- ; 6J in. (See Nos. 1527-1530 for other patterns.) £0 1 3 3840 3840s Sodium Wire Press, with cylinder, 15 millimetres diameter, bored with hole 0.5 millimetre diameter . . . . . . " . . . . . . . . . . . . £3 15 0 725 BAIRD &TXTLOCK (LONDON) LTD. 3841 384 1T Sodium Press, Prof. Dr. A. Kossel's, for one-tenth normal sodium solutions DIRECTIONS FOR USE. Before commencing the pressing operation the stamp should be wiped over with paraffin oil. The piece of sodium, about 20 millimetres in length, dug out with a suitable cork-borer, is rolled dry on filtering paper, pressed into the cylinder, above which the cap is then screwed down, and the cylinder is screwed on to the press. Then the screw is turned until the wire protrudes from the presshole ; for greater convenience of taking readings, the apparatus is set to the division for hundreds. The protruding wire is cut off and removed. Now the pressing commences, after the completion of which the wire is at once cut off. The sodium is pressed into a fairly large beaker, containing 30 cubic centimetres of alcohol. After the pressing operation the beaker is covered up until the solution has cooled down. It is then filled up with water to make up half a litre. In the pressing operation, the press hole, stamp, and cylinder should be thoroughly cleansed with alcohol, and the stamp should be wiped over with paraffin oil. Otherwise the stamp may easily stick in the cylinder, causing the press to be damaged. When the press is not in use the cap, stamp, and cylinder should be coated with grease, and the stamp should be screwed np as high as possible to prevent it from rusting. £5 0 0 3842 3842 Fletcher's Registered Self-Heating Soldering Bit This is free from smell, heats rapidly, and will be found a first-class arrangement for case-makers' stained glass leading, sardine box making, and similar work. It is not suited for the heaviest class of coppersmith's work. The copper can be renewed in a minute when worn down. The gas supply from an ordinary bracket, with the gas burner removed, will be found ample. £0 7 3843 3843 Fletcher's Burner, with hood for heating soldering bolts. Price without bolts . . This will heat one bolt and keep another nearly ready for use, so that two can be used in succession. £036 14 • CROSS STREET • HATTCHSr GARDEN, E-C 726 BAIRD &TATLOCK (LONDON) LTD. 3844 (Fig. A) 3844s Science Lantern, improved form, for vertical and horizontal projections. Lantern as described below, in case, with limelight burner The lantern is of a neat and portable form, and is provided with a well-made case, fitted with hooks and leather strap for carrying. The objective front is supported by double telescopic draw tubes, which allow a long extension, worked by a handle actuating a triple quick screw, by means of which the objective can be quickly brought into focus without any of the usual jerking and pulling. Fig. A shows lantern as used for projecting ordinary lantern slides, scientific apparatus, etc. ; the necessary space and proximity to condenser required by some experiments being readily obtained. Fig. B shows vertical projection, used in showing lines of force, chemical combinations, drawing diagrams, etc. It is only the work of a few seconds to transform the projection from the horizontal to the vertical. To do so simply — 1. Raise front half of condenser and slip reflecting mirror into its position. 2. Unbayonet objective and refix on upright rod. This method of vertical projection obviates the necessity of having extra condensers and objectives. £9 10 0 3844 (Fig. B) (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 727 BAIRD &TATLOCK (LONDON) LTD. 3846-3847 3846 Science Lantern, larger pattern, for vertical and horizontal projections with hand-fed arc lamp, rack and pinion adjustment for carbons to raise or lower and screw to work carbons from right to left. Price, with suitable resistance for currents up to 100 volts, fitted with portable case with leather strap 3847s Science Lantern, as above, with resistance suitable for currents up to 200 volts This lantern is fitted with polished mahogany body with panelled brass shuttered doors, and is lined inside with Russian iron asbestos covered. It is fitted with 5-in. condensers and double achromatic lens with rack and pinion adjustment. The objective front is supported by double telescopic draw tubes, and is worked by means of triple quick- acting screw which allows of the objective being quickly brought in focus. When ordering, please state voltage of current available and whether continuous or alternating. £19 10 0 £20 10 0 384S 3849 3848 Specific Gravity Bottles, accurately adjusted with drilled stoppers. 10 25 Or 100 250 Price .. .. .. .. 1/3 1/9 14/- 18/- 50 500 2/3 25/- 100 grammes. 1,000 grains. 2/9 each. 30/- per doz. 3849 Specific Gravity Bottles, as No. 3848, accurately adjusted with drilled stoppers, with 'brass counterpoise in japanned tin case. 10 25 50 100 grammes. Or 100 250 500 1,000 grains. Price .. .. .. .. 3/- 3/3 4/- 4/6 each. CROSS STREET • HATTOTST GARDEN, E-C ess? BAIRD &TATLOCK (LONDON) LTD. 3851 350s Specific Gravity Bottle, standard, 1,000 grains adjusted to case, with counterpoise 3852 grain, in japanned Specific Gravity Bottle, Warden's, made of Resistance glass, with cap ground on over capillary stopper, adapted for use in hot climates, with case and counterpoise. (See Chemical News, isth November, 1899.) 50 grammes. 5/6 each. 100 grammes. 6/- each. 552 Wanklyn's Specific Gravity Bottle, 500 grammes (see Wanklyn's " Water Analysis ") . . 553 Specific Gravity Bottle, with thermometer stopper, and scale outside. £0 15 0 £0 10 6 Price 10 25 50 grammes. Or, 250 500 1,000 grains. .. 4/- 4/6 5/- each. 3853 3854 3855 ; 54 Specific Gravity Flask, for taking the specific gravity of gases, by C. Chancel . . . . £086 ; 55 Specific Gravity Bottles, with wide necks and round glass disc, for syrups, etc., adjusted. A. 50 1/6 B. 100 cubic centimetres. 2/- each. 729 BAIRD &TATLOCK (LONDON) LTD. 3856 3857 3858 3859 3856 Specific Gravity Bottle, thermometer stopper, with scale outside, and mark on side tube, 25 or 50 cubic centimetres 3857 Specific Gravity Bottles, by Regnault, stoppered, with mark on neck. 25 50 Price 1/3 1/6 £060 100 grammes. 2j- each. 3858 Picnometer with round bulb and capillary tube with funnel ground to fit. Capacity about 50 c.c. . . . . . . . . • • • • each, 8d. ; per doz. £0 3859 Specific Gravity Tubes with mark on neck, graduated. I 2 2/- 3/- 3860 Specific Gravity Beads, for butter, 0.865 at 15° C. . . 3861 „ „ „ for gin, 35 U.P. 3862 „ „ „ for whisky, brandy, and rum, 25 U.P. 5 c.c. graduated into ^ c.c. 3/6 each. each £0 1 £010 £0 1 0 3863 3863 Specific Gravity Beads, set of 12 in box, 60 U.P. to 45 O.P. 3864 „ 18 „ 75 „ 63 „ CROSS STREET • HATTOTST GARDETST, E-C- 730 BAIRD &.TATLOCK (LONDON) LTD. 3865 3866 3867 3868 3! 5 Specific Gravity Apparatus, for measuring the specific gravity by rapidity of diffusion . . £080 3t6 Specific Gravity Bottles, for solids and liquids .. .. .. .. . . £0 10 6 317 Glass Bulbs, for determining the specific gravity of gases, with two stopcocks and hook for suspending from balance. Capacity . . . . . . . . . . 1,000 2,000 c.c. Price . . . . . . . . 8/- 9/- each. 3J 8 Bulb Pipette, with two stopcocks, ground in tube, by Lunge and Rey (Zeitschri/t f.a. Chemie, 1891, p. 165), for estimating the specific gravity of fuming acids, etc., 5 cubic centimetres capacity . . . . . . . . . . . . . . ..£076 3869 3870 3871 3£ 9 Sprengel Tubes, for taking specific gravity of oils, etc., U form. Capacity . . . . . . . . . . 10 20 Price .. .. .. .. ..1/6 1/7 30 c.c. 1/9 each. 360 Specific Gravity Cubes, of magnesium, aluminium, zinc, tin, iron, nickel, copper, silver, lead, aluminium bronze, brass and bronze, each i cubic centimetre, in case . . . . £1100 3£ 1 Specific Gravity Cylindrical Rods, of same metais as above, each 5 millimetres diameter, and of equal weight, 10 grammes, in case, to illustrate relative specific gravities £1 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 731 RAIRD &TATLOCK (LONDON) LTD. 3874 3872 3873 3875 3872 Nicol's Specific Gravity Tube. Capacity about 5 c.c. each 10 c.c. 3873 The Pollard Regulator This simple device is for maintaining a normal temperature in a given liquid for several hours, and is primarily intended for taking accurate gravities with a Westphal or chemical balance, or for determining solubilities at standard temperature. The outer vessel contains a specially prepared Acetic Acid with melting point exactly 60° F. ; the latent heat of which is used for maintaining the tetnperature. DIRECTIONS. During the winter months the acid will be frozen ; it must be melted, or nearly so, before the apparatus is used. During the subsequent regelation, energy is given out to maintain a normal temperature for hours. Thus the "capacity" of the instrument is about sixty "degree-hours." Supposing the laboratory tempera- ture be 50° F., the liquid in the inner tube will be maintained at 60° for six hours, during which time many gravities can be taken. During the time the atmospheric temperature is above 6og F., the use of cooled water is necessary to freeze the acid, and the "capacity" of the apparatus is necessarily lessened. The temperature is so accurately regulated that no thermometer is necessary. CATjTION. — Superfusion must be avoided by shaking, or by the cooling of some part of the apparatus with a few drops of ether. 3874 Spoons, iron small 3875 Spoons, heavy glass . . per doz. . . each, teaspoons, 6d. ; tablespoons £0 0 £0 1 Price £0 5 £0 1 £0 1 3876 3876 Spoons, horn. Length Price ,, . . 3877 Spoons, horn, with spatula ends. Length Price 4 4d. 3/6 5 5d. 4/6 3877 6 6d. 5/6 7 6d. 5/6 8 in. lOd. each. 9/6 per doz. , 8J in. lid. each. 10 /- per doz. CROSS STREET • HATTCflST GARDE1ST, E-C 732 BAIRD &TATLOCK (LONDON) LTD. 878 Capsule Spoon, length 6 in. 879 Spoons, sodium, wire gauze, with cover 880 Spoons, platinum, for blowpipe work. See Nos. 2360^2360. 881 Slips of Glass, blue, for furnace or blowpipe work. 6 by 6 4 by 4 3 by 3 4/- 2j- 1/6 each, 4d. ; per doz. £036 each £016 3 by i Jin. I/- per doz. Stands and Supports. . 3882 3883 3884 82 Filter Stands, for single funnels, varnished black . . . . each, 1/1 ; per doz. £0 12 0 ; 83 Filter Stands, for single funnels, with oblong sole, varnished whitewood „ 1/9; c84 Filter Stands, varnished, double, oblong sole . . . . ,,2/3; 385 Filter Stands, varnished, double, longer sole and arm . . „ 2/8 ; „ £100 £140 £1 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 733 BAIRD &TATLOCK (LONDON) LTD. I 3886 3887 3886 Pipette Rest, porcelain 3887 Filter Stands, mahogany, for two funnels . . 3888 each £0 1 each, 3/- ; per doz. £1 15 3888 Filter Stands, mahogany, polished, double, larger sole and funnel holder each £0 4 3889 3890 3891 3889 Filter Stands, mahogany, polished, double, with porcelain sole . . ... each £0 5 3890 Filter Stand, with iron tripod base, rod, and three iron rings lined with porcelain ,, £0 6 1 3891 Pipette Stands, circular, with porcelain sole, 10 in. diameter, with teak pipette holder, slotted and adjustable in height for pipettes of various sizes . . . . each £0 12 i CROSS STREET • HATTGTST GARDEN, E-C 734 BAIRD &TATLOCK (LONDON) LTD. 3892 892 Retort Stands, iron, oblong sole, with smooth iron rods screwed to fit. A B C D E Size of base . . 4i by 3 6 by 5 8 by 5 9 by 5} 12 by 6 „ of rod . . 15 by T5T 18 by f 22 by TV 24 by TV 30 by i Price .. I/- 1/2 1/6 2/3 3/6 11/6 13/- 17/- 26/- 40/- •893 Retort Stand, iron, 12 by 6 in. sole, with iron rod 30 by i in. in centre of base •894 Retort Stand, „ „ „ „ 36 by J in. „ F 12 by 6 in. 36 by £ „ 4/- each. 46/- per doz. each £036 £040 3895 895 Retort Rings, malleable cast iron, with open bosses and brass clamping screw, to fit rods up to i in. diameter. Inside diameter of rings Price 2 2j 3i 3J 4i 5 6 in. 7d. 7d. 7d. 7d. 9d. lOd. I/- each. 6/6 6/9 6/9 6/9 8/6 9/6 11/6 per doz. Brass rings, see No. 3897. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 735 BAIRD &TATLOCK (LONDON) LTD. 3896 3896 Tripod Stands, of cast iron, with smooth iron rods, screwed to fit. 3 3f I l| 2^ 15 by A 18 by | 24 by T7, 1/3 1/9 21- 14/- 201- 23/- Size Spread of legs to centres Weight of sole about . . Rod . . Price 2 3 4 5 3f 30 by 3/- 34/- 7 in. 6f Ibs. 36 by J in 4/6 each. 52 /- per doz. 3897 3897 Retort Rings, brass, with open bosses and brass clamping screws, to fit rods up to \ in. diameter. Diameter . . . . 2 2| 3^ 3f 4^ 5 6 in. Price .. .. 9d. 9d. lOd. lOd. lid. 1/2 1/4 each. . . 8/6 8/6 9/6 9/6 10/6 13/- 15/- per doz. Iron rings, see No. 3895. CROSS STREET • HATTCnST GARDETST, E-C 736 BAIRD &TATLOCK (LONDON) LTD. 3898 3899 3900 3903 $98 Retort Stand for Nitrometers, iron base, 12 by 6 in., with smooth iron rod, 30 by | in., screwed to fit, and fitted with double right and left hand screw nitrometer clamp, each clamp hinged to fix in any horizontal position . . . . . . . . each i99 Retort Stand, iron base 4^ by 3 in., rod 15 in., with three brass rings . . each £0 11 6 £026 •00 Student's 'Retort Stand, cast iron base, 5j by 3j in. with bright iron rod 15 by ^ in., screwed in base, and three malleable iron rings, ij, ij, and 2f in. diameter, with brass pinching screws, price complete .. .. .. .. each, 1/6 ; per doz. £0 17 6 '01 Student's Retort Stand, price, stand and rod only . . • 02 Student's Retort Stand, price, rings only . . 8d.; 4d. ; £076 £039 Retort Stand, iron sole, 8 by 5 in., with 22 in. smooth iron rod screwed to fit, and one each malleable iron rings with open bosses, 2 1, 3 J, and 4 in. diameter .. .. .. £033 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 737 BAIRD &.TWLOCK (LONDON) LTD. 3904 3905 3904 Retort Stand, iron sole, 8 by 5 in., with 22 in. smooth iron rod screwed to fit, three malleable iron rings with open bosses, af, 3^, and 4 in. diameter, one each Nos. i and 2, right and left screw clamps (No. 3911) and bossheads (No. 3916) to suit . . each 3905 Retort Stand, base 12 by 6 in., rod 36 in. high, five malleable iron rings, open bosses to suit, also three screw clamps, small, medium, and large, of approved pattern (Fig. 39IT)> burner with slot and chimney, sliding on fork, porcelain plate, complete £1 3906 Retort Rings, malleable iron, plain, for use with bosshead, Figs. 3916-3917. Inside diameter of rings 2 2j 3 4 4j 5 6 in. Price, without bosshead 5d. 6d. 7d. 7d. 7d. 9d. lOd. each. CROSS STREET • HATTOTST GARDEN, E-C 738 BAIRD &TATLOCK (LONDON) LTD. 3907 3908 3907 Table or Support, 4 in. diameter, with boss, to fit on retort stand 3908 Clamps, burette, plain, with spring 3909 Clamps, burette, jointed, with spring 3909 each, 1/6; per doz. £0 17 6 each £020 £026 rr 3910 3911 •910 Clamps, double nitrometer, with right and left screws, and hook for suspending thermometer, made in gun -metal, each clamp hinged to fix in any horizontal position . . each £080 '911 Clamps, for burettes, condensers, etc., with right and left hand screw, with malleable iron bosshead for fitting to stands, adjustable to any angle, clamps of gun-metal with iron rod for bosshead. No. To hold tubes up to Price, with bosshead . . I i 31- 33J- 2 I* 3/6 40/- 2j 3 in. diameter. 4/6 SI- each. 52/- 58/- per doz. No. 4 size is in malleable iron. 912 Clamps, as above, same pattern, but of superior finish, of polished gun-metal, lacquered. No. . . . . . . . . . . i 2 Price . . . . . . . . . . 4/6 5/6 each. 913 Clamps, medium, same form as No. 3911 (No. 3), with adjustable jaw, suitable for holding • tapering tubes, such as retorts, with bosshead . . . . . . . . each £056 BAIRD &TATLOCK (LONDON) LTD. 3914 3915 3914 Clamps, with right and left screw and double jaws . . 3915 „ „ pinching screws to adjust jaws at any angle Bossheads, malleable iron, with brass screws, for above clamps. 3916 Small, for clamps Nos. i, 2, and 3 3917 Large „ No. 4 3916-3917 each £0 4 • £04. each, lOd. ; per doz. £0 9 < 1/1 ; £0 12 i 3918 3918 Tube Holders, to fit on retort stands 3919 3920 3919 Test Tube Stands, of teak, with one row of holes (diameter of holes f in.). 6 8 Price .. .. .. .. 8d. 9d. 7/6 8/6 3920 Test Tube Stands, of teak, with two rows of holes (diameter of holes f in.). 12 18 I/- 1/6 Price 11/6 171- 3921 12 holes. I/- each. 11/6 per doz. 24 holes. 2/- each. 23 /- per doz. 3921 Test Tube Stands, of teak, with one row of holes and draining pegs (diameter of holes £ in.). 6 8 12 holes. Price .. .. .. .. I/- 1/3 1/9 each. 11/6 14/6 20/- per doz. CROSS STREET • HATTON GARDE1ST, E-C 740 J. BAIRD &.TATLOCK (LONDON) LTD. 3922 3923 3922 Test Tube Stands, of teak, with two rows of holes and one row of draining pegs (diameter of holes | in.). 12 18 24 holes. Price .. .. .. .. 1/6 2/3 2/6 each. 171- 26/- 29/- Per doz- 3923 Test Tube Draining Stands, of teak, with pegs only. Sets of . . . . . . ia 18 24 36 pegs. Price .. .. .. .. 1/6 2/3 ' 2/6 3/6 each. 3924 3925 5924 Draining Tube Rack, porcelain . . 5925 Test Tube Stands, teak, two stages (diameter of holes £ in.). Price 12 1/6 18 2/3 •926 Test Tube Stands, with holes and drying pegs, holes for funnels and drawer 3926 £026 24 holes. 2/9 each. each £056 3927 3928 3929 927 Test Tube Stands, twelve holes (diameter f in.), ten for ordinary test tubes, two for boiling tubes (diameter i J in.) .. .. .. .. .. each, 1/3; per doz. £0 14 6 928 Test Tube Stands, for six boiling tubes, holes i j in. diameter each, 1/9; per doz. £100 l)29 Test Tube Stands, for six boiling tubes, holes i| in. diameter, with seven pegs each, 2/3; per doz. £1 60 iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. *L 741 BAIRD &TATLOCK (LONDON) LTD. 3930A 3930B 3930 Burette Stands for burettes with stopcock, varnished whitewood, with boxwood pinching screws. A B For . . . . . . . . . . I 2 burettes. Price . . . . . . . . . . 2j- 2/9 each. 23/- 32f- per doz. 3931A 3931B 3931 Burette Stands, polished mahogany, best finish, with boxwood pinching screws. For Price i 3/6 40/- B 2 burettes. 5/- each. 58/- per doz. CROSS STREET • HATTCTST GARDEN, E-C 742 BAIRD &TATLOCK (LONDON) LTD. 3932 3933 )32 Burette Stands, polished mahogany, best finish, with boxwood pinching screws on white porcelain sole . . . . . . . . . . each, 6/6 ; per doz. )33 Burette and Filter Stand combined, in mahogany . . . . each, 41- ; per doz. £3 16 £26 3934A ^34 Burette Stands, teak, for burettes without stopcocks. For Price 3934B A i B 2 burettes. 2/6 each. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 743 BAIRD &TATLOCK (LONDON) LTD, 3935 3936 3937 3935 Table Supports, iron tripod base, brass pillar, with mahogany table on sliding rod, very serviceable for lecture table. Height in lowest position . . . . . . 8 10 12 hi. highest ,, . . . . . . 13 18 21 ,, Diameter of table . . . . . . . . 3! 5 6 ,, Price . . . . . . . . . . 4/- 4/6 5/6 each. These can be made to any dimensions to order. 3936 Table Support, polished mahogany, with crook on sliding pillar, for supporting tubes, etc. Height hi lowest position . . . . . . . . • • 9 12 in. „ highest ,, . . . . . . . . . . 14 17 „ Price . . . . . . . . . . . . . . 2/6 3/- each. 3937 Table Supports, mahogany, turned and varnished, with loaded base. Height of lowest position . . . . . . 8 10 12 hi. Rising to . . . . . . . . 13 15 18 „ Price . . . . . . . . . . 3/3 3/9 4/6 each 3938 3938 Condenser Stands, iron tripod base, upright metal slide support, -brass clamp adjustable to any angle, all metal . . . . . . • • . . . . . . each £0 6 CROSS STREET • HATTOTST GARDETST, E-C 744 BAIRD &TMTLOCK (LONDON) LTD. 3939 3940 3941 3939 Condenser Stand, on heavy iron tripod base, with brass rod and clamps adjustable to any angle and height, and fit any size condenser . . . . . . . . each £012 0 3940 Stand, universal, brass pillar, iron tripod base, with sliding rod arranged to clamp tubes, etc., in any position, fitted with No. i right and left screw clamp . . . . . . £076 Any of our right and left screw clamps (No. 3911) suit this stand. 3941 Stand for water decomposing apparatus, iron tripod base, brass upright and clamp and double terminal screws £0 12 0 3942 3943 3944 3942 Wooden Stand for water decomposing apparatus, with double terminal binding screws 3943 Stand, mahogany, varnished, with movable clamp for retorts, flasks, &c., loaded base 3944 Stand, mahogany, varnished, with joint at foot, for retorts, flasks, etc., loaded base 3945 Stand, clamp for raising or lowering, mahogany .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 745 BAIRD &T&TLOCK (LONDON) LTD. 3946 3947 3946 Carnegie's Universal Stand, i8-in. rod with loaded base, clamp adjustable to any angle £0 3947 Hoffmann's Stand, iron tripod base, with sliding mahogany table and two forked rods for tube supports 3948 3949 3948 Blocks, wooden, set of six, 4 in. square, 4, 2, i, J, J, J in. thick 3950 3949 Compressed Cork Rings (Suberit), for supporting flasks, etc., all about if in. deep. No. Diameter outside Diameter inside Price 123 9k 7i 6 7l 6J 4| 1/9 1/7 1/4 201- 17/6 14/6 Complete set, Nos. i to 5, 6/-. 3i I/- 10/6 £0 i: set £0 I 9d. each. 8/6 per do 3950 Compressed Cork Mats (Suberit) for placing beakers and flasks on. No. . . i 2 3 4 Diameter Thickness Price 4i 4l 41 ii I* i i 1/3 1/2 I/- lid. 13/- 12/- 111- 10/6 Complete set, Nos. i to 6, 5/3. 5 6 4i 4f in. i » 9d. 7d. each. 8/6 6/6 per do CROSS STREET • HATTON GARDETST, E-C 746 BAIRD &TATLOCK (LONDON) LTD. (51 Stirring Rods, ends glazed ready for use. Length .. .. 6 8 Price 9d. I/- (See No. 4301 for I.R. ends.) 12 1/6 14 16 in. 3/- per doz. ' 3952 Carboy Barrow of iron, strongly made, weight about 84 Ibs. This barrow will be found very convenient for works and laboratories where carboys have to be frequently moved £2 15 0 3953 3 >3! Carboy Stand, on iron stand, with handle for tilting . . . . each This stand or tilt supplies a want much felt by all using acids. In emptying acid from the carboys there is ways the danger of it slipping and spilling, and most probably burning the feet of those pouring it out, and m unfrequently breaking the carboy itself. Hv using this stand or tilt with ordinary care these dangers are entirely avoided, no slipping or spilling of i can take place. The carboy cannot be broken, as it is securely fastened in the cradle. The stand is m. e to suit any size of carboy, and can be worked with perfect ease and safety. £2 10 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. | 747 BAIRD &TATLOCK (LONDON) LTD. 3954 3954 Stirring Apparatus, Witt's pattern, complete with water turbine, stands and clamps, but without indiarubber tubing .. .. .. .. .. .. ..£15 3955 3955T Simple Laboratory Shaker (as devised by Professor W. R. Dunstan and Mr. T. S. Dymond, and used in the Research Laboratory of Pharmaceutical Society), for the extraction of solids with li quids ; the desiccation of organic liquids with solid drying agents ; the chemical action of liquids on substances not freely soluble ; the mechanical mixture of liquids for the production of emulsions, etc. (See Nos. 908-913 for Water and other Motors to drive above.) The shaker consists of a wooden truck into which can be firmly 'fixed, by means of a sliding partition, a bottle or other vessel of any size up to that of a Winchester quart. This truck is supported underneath near the front by a rod which can move backwards and forwards on a pivot. At the back the truck is supported by two supports hinged, one end of each being fixed to either side of the truck, the other end being firmly fitted in the base board of the machine. The necessary to-and-fro motion is communicated to the truck in the usual manner by means of a crank connected with a revolving wheel, and attached to the truck by an iron rod This rod can be connected with the crank at different distances from the axle, so that the extent of the excursions made by the truck may be varied. A cord from a water or other small motor passes over the wheel, which is grooved at three distances from the centre so that the rate of action may be regulated. In order to avoid the necessity of altering the length of the cord which passes from the motor to the wheel, the base board of the apparatus is provided with slots and thumbscrews, by means of which it may be securely fixed to the bench at different distances from the motor. For shaking liquids in large vessels, the extent of the excursion of the truck should be greater and the rate of motion less rapid than when small vessels are employed. £2 5 CROSS STRET • HATTCTH GARDETST, E-C 748 RAIRD &TATLOCK. (LONDON) LTD. 3956 3956s Shaking Machine for use in water baths where it is required to shake continuously at a constant temperature. Shaker is made of copper on a heavy iron stand, and will carry bottles up to i litre capacity. By altering the position of the connecting rod in the driving wheel the angle at which the shaker will work can be varied as required £3 12 6 A3956 \3956S Copper Thermostat Bath for above shaker, 18 by 12 by 12 in., covered with felt and mounted on iron stand with burner, thermometer, and Lowry's gas regulator £350 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 749 BAIRD &TATLOCK. (LONDON) LTD. 3957 3959-3960 3957s Simple Form Shaking Machine, with clamp for carrying i litre bottles, mounted on stand to clamp to table, complete with Rabe turbines . . . . . . £1 12 3958- Similar Shaker, adapted to take 2 litre bottles . . . . . . . . ..£118 3959s Shaking Machine, to carry either 6 bottles or 6 conical flasks, with rotary motion. Price with water turbine . . . . . . . . . . . . . . ..£350 3960s Price without water turbine . . . . . . . . . . . . £2 15 0 Large Shaking Machine for shaking bottle of large capacity, mounted on roller, adapted for either hand or power driving. 3961s Price for bottles up to 3 litre capacity £450 3962s Price of bottles up to 5 litre capacity £4 17 6 3963s Price for bottles up to 10 litre capacity £5 10 0 3961-3963 CROSS STREET • HATTON GARDETST, E-C 750 BAIRD &TATLOCK. (LONDON) LTD. 3964 264s Shaking Machine, mounted complete with hot air engine and adapted for shaking 2. bottles up 5 litres capacity. Price as illustrated . . . . . . . . . . . . £9126 355s Ditto, without hot air engine .. .. .. .. .. .. .. £3 15 0 356s Pulley Cord, of best cat-gut, for use in laboratory for driving shakers, etc. Diameter 3'j7s Hooks and Eyes for above. Price 6d. Price 9d. 9d. 9d. Jin. 1 /6 per yard. 9d. per parr. 3968 Set of Wheels for varying speeds, ij, 3, 5, 7, and 10 in. diameter, grooved for belt and mounted on heavy wood base for screwing to table . . . . . £2100 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 751 (LONDON) LTD. SMALL CONTINUOUS-CURRENT MOTORS FOR OUTPUTS UP TO 1 B.H.P. B— D 3970-3971 E 3973-3974 F. With spring suspension 3975-3976 These motors are not fitted with commutation poles. Small Motors with Standard Pulley. For 6, 12, 1 10 and 220 volts. Speed Power PRICE. SIZE. oui- R.P.U. taken. Diam. Width Nett Gross B.H.P. within 7% approx Watts. 6 volts. 12 volts. no volts. 220 volts. ins. ins. Ibs. Ibs. 3963s 1/100 22OO 21 42/- 36/- 36/- — M IX 2j 5 3970s 1/40 22OO 46 45f- «/- 42/- 451- U 1 'z 5 9 v6- 3971s 1/16 2OOO 8$ — 56/- 51/- 541- 'ft 1 »1 «7i 3972s 1/6 1900 190 — 85'- 79/- 82/- if )u 20 29 3973s 3974s 1/6 i/4 1500 2IOO 190 270 — 130/- 130/- 1I5/- 115/- 120'- 120/- 23 19 41 55 3975s 3976s 1/3 1/2 I4OO 20OO 360 520 — 160/- 160/ 165/- 165/- 3 "4 66 88 CROSS STREET • HATTON GARDEK, E-C BAIED &TATLOCK. (LOM)ON) LTD. SMALL THREE-PHASE MOTORS, ALTERNATING CURRENT, FOR OUTPUTS UP TO 4 B.H.P. SO FREQUENCY. Model I. Motor with squirrel-cage rotor. Model II. Motor with squirrel-cage rotoi for star-delta starting. Model III. Motor with slip-ring rotor. Model IV. Motor with brush-lifting device. 50 Frequency Three-Phase Motors with Standard Pulley. At full load With Squirrel-cage rotor With slip-ring rotor Belt pulley Weight Line Current (approx.) Extra if for Extra SIZE PUT Speed I2O 210 volts 500 volts I Star- delta start- volts \ 500 for en- closed slip- Diam Width Nett Gross I II III ing* V VI VII rings. B.H.P. R.P.M. Amps Amps Amps IV VIII ins. ins. Ibs. Ibs. 3977s i/4 2800 i'7 I'O _ 95/- 95/ _ _ — Ift _ 26 44 3978s 1/2 n 27 1-6 — 1IO/- no/- 101- — — — *8 4 44 66 3979s I 2850 5'3 3'o I '3 140/- 140,'- I40/- 101- — — 3 'i 70 no 3980s 2J 29OO I2'O 7-0 2'Q 2101- 210/- 210/- 101- ___ 48 2 125 »75 3981s 4 n I9-0 I I'O 4'5 280/- 280/- 280/- 101- — — . ""•~ 58 2xrl ...^ 4014 4015 4014 Stopcocks, glass, with capillary tubes, i to 2 millimetres bore . . 4015 Stopcocks, glass, for aspirator bottles. Bore of plug . . . . • • 3 4 Price .. .. . . 2/- 2/6 4016 Stopcocks, glass, three-way. Bore of plug Price 4016 each 8 5/- 2 2/6 10 mm. 6/- eac 4 mm. 3/6 each. Greiner and Friedrich's Original Patent Glass Stopcocks, well-made and carefully ground. These stopcocks are made with oblique borings, and so avoid the furrow formation between collar and stopper, which so soon causes the ordinary stopcock to leak. In the case of the three-way stopcocks they are opened and closed by a turning of 90° and 180° instead of 45°, which much facilitates exact work. 4017 4017 Stopcocks, glass, with straight tubes. Bore of plug Price ........ 2 3 4 n 2/4 3/- 3/6 each. 4018 Stopcocks, glass, with straight tubes, capillary bore, i to 2 millimetres bore of tube. Same pattern as No. 4017 . . . . . . . . . . each £0 4019 Stopcocks, glass, with straight tubes and mercury cup. Bore of plug .. .. .. .. .. 2 3 4 mm- Price . . . . . . . . . . . . 4/- 51- 5/6 each. CROSS STREET- HATTCTNT GARDETST,E;G 756 BAIRD &L TATLOCK (LONDON) LTD. 4020 4021 4020 Stopcocks, glass, with straight tubes and mercury cup, three-way. Bore of plug . . . . . . 2 Price 4021 Stopcocks, glass, with straight tubes, three-way. Bore of plug Price SI- 6/6 4 mm. »/- each. 3 3/6 4 mm. 41- each. 4022 4023 4022 Stopcocks, glass, with diagonal bore plugs and straight tubes, capillary bore, three- way, i to 2 millimetres bore of tube . . . . . . . . . . each £046 4023 Stopcocks, glass, with straight tubes, three-way with outlet at bottom. Bore of plug ...... 2 3 4 mm. Price 3/- 3/6 4/3 each. 4024 4025 4024 Stopcocks, glass, four branches, 2 millimetres bore of plug 4025 Stopcocks, glass, three-way, 3 millimetres bore of plug 4026 Stopcocks, glass, two branches, T shape, 2 millimetres bore of plug 4026 each £029 £033 £030 757 _ BAIRD &TATLOCK (LONDON) LTD. 4027 4028 4027 Stopcocks, nickel-plated, for aspirator bottles, etc. . . 4028 Stopcocks, for fusing to burettes 4029 Stopcocks for fusing to burettes, vertical drip 4029 each £020 £016 £0 1 9 4030 4031 4032 4030 Stopcock, vulcanite . . . . . . . . . . each, 9d. ; per doz. £086 4031 Stopcock, vulcanite, for gas bags, etc. . . . . . . „ 9d. ; „ £0 8 6 4032 Stopcocks, vulcanite, for aspirators, etc., bore of plug 5 millimetres . . . . each £020 4033 4034 4035 4033 Stopcocks, vulcanite, for aspirator bottles, extra large size, bore of plug 8 millimetres, each £0 76 4034s Stopcocks, stoneware, for acids. Bore . . . . £ | f i ij i J- 2 in. Price . . 2/6 3/6 5/6 9/- 14/- 20/- 35/- each. 4035s Stopcocks, stoneware, vertical drip, suitable for aspirator bottles . . . . each £020 CROSS STREET • HATTCHSr GARDETST, E- C 758 BAIRD &.TATLOCK. (LONDON) LTD. 9 4036 4037 4038 4036 Stopcocks, brass, with straight tubes, ends corrugated for I.R. tubingv Bore . . . . . . . . . . . . J Price . . . . 1/9 4037 Stopcocks, brass, three-way, ends corrugated, J in. bore 4038 Stopcocks, brass, four-way, ends corrugated, J in. bore Jin. 2/9 each. each £036 £040 4039 4039 Stopcocks, brass, Y shape, ends corrugated, J in. bore 4040 Stopcocks, brass, T shape, ends corrugated, J in. bore 4040 each £046 £046 Illustration shows Apparatus No. .44040 connected up ready for use. A4040 A4040 Odourless H2S Apparatus, as used in the Admiralty Chemists' Department, H.M. Dock- yard, Portsmouth This is a simple apparatus for attaching to a Kipp's or other Sulphuretted Hydrogen Generator, by means 51 which the nuisance due to escape of gas may be entirely prevented. For full particulars and description see separate pamphlet on application. £0 17 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 759 -V BAIRD &TATLOCK. (LONDON) LTD. 4041 4042 4041 Apparatus for obtaining a saturated aqueous solution of sulphuretted hydrogen or a constant supply of the gas. Complete on stand, by F. Millwo Perkin, Esq. (see J.S.C.I., No. 5, vol. xx., 3ist May, 1901) . . . . . . . . . . £1 12 6 4042 Sulphuretted Hydrogen Apparatus, L. de Koninck's, on wood stand, with I.R. tubing and corks complete . . . . . . . . . . . . . . . . £1 10 i 4043 4044 4045 4043 Kipp's Apparatus for Chlorine, modified by Professor Dittmar 4044 Sulphuretted Hydrogen Apparatus, Kipp's, with stopcock in centre bulb ground to fit, extra large top bulb. Diameter of centre bulb . . . . 3 4 5 6 7 in. Capacity of centre bulb about i i i£ 2 litres. Price . . . . . . . . 8/- 9/6 12/- 15/- 18/- each. 4045 Sulphuretted Hydrogen Apparatus, Babo's, on hardwood stand, complete . . . . £0 4046 Sulphuretted Hydrogen Apparatus, Babo's, glass, without stand - . . £0 £0 8 5 6 2 0 CROSS STREET • HATTCTrSr GARDEN, E-C 760 BAIRD &TATLOCK. (LONDON) LTD. 4047 047s FriswelPs Improved Apparatus, for Sulphuretted Hydrogen, CO2 Hydrogen, etc. Diameter of centre bulb Price 4 15/- 5 21/- 6 in. 25/- each. (Chemical News, 23rd September, 1904.) FRISWELL'S IMPROVED KIPP'S APPARATUS. ADVANTAGES. The following serious defects observed in working the ordinary Kipp's apparatus are reduced to a minimum, id, in fact, practically abolished in Friswell's apparatus. 1. Rapid degeneration of the acid liquids and early appearance of sluggishness in reaction. 2. Wastefulness of acids. 3. Necessity for frequent recharging. DESCRIPTION. The form of the apparatus — shown in the above illustration — may be briefly described as consisting of the sual three bulbs. In bulb I a ground-in tube passes down to the bottom of the lowest bulb. B is a stopcock >r drawing off the contents of i. c is the usual outlet for the gas in bulb 2. METHOD OF USING. Before use the tube A must be securely fastened into its seating in bulb i. To do this, gently warm the round part of the tube and of the bulb, then smear on the ground part of the tube a very small quantity of good esh marine glue. Press the tube firmly home with a turning movement. None of the glue must get on to the jter ground neck of bulb i. Charge the centre bulb 2 with the marble, zinc, or ferrous sulphide, and pour down IB centre tube by means of a funnel sufficient strong calcium chloride, zinc sulphate, or ferrous chloride solution > fill the lower bulb nearly to the top. Now pour in the acid until the uppermost bulb is so filled that the acid :ands an inch or so above the flared lip of the standing tube A. Open the gas cock slightly so as to allow the ;:id to descend very slowly through the centre tube. When it reaches the bottom of the apparatus, it rises irough the strong salt solution and reaches the centre bulb at nearly full strength, and when the gas pressure I ses, the exhausted liquor will be slowly pressed back to the upper reservoir, and is particularly noticeable when ic gas cock is closed. The liquids having changed places, the strong salt solution forced back to replace the acid will be seen falling ver the lip of the flared tube in the upper reservoir through the stronger acid therein. When an accumulation f this denser liquid in the upper reservoir takes place to such an extent that its level approaches the upper part f the standing tube, it is drawn off by the cock B and fresh acid carefully poured into tube A by means of a funnel. 761 BAIRD &.TXTLOCK (LONDON) LTD. f C? 4048 4049 4050 4051 4048 Sulphuretted Hydrogen Apparatus, Coram's, suitable for students and others requiring a moderate and constant supply 4049 Syphons, glass, with suction tube and safety bulb. Length of arm . . . . 12 Price, plain . . . . . . l/- 4050 Syphons, glass, with stopcock 2/9 15 1/1 a/. 18 1/4 3/3 21 1/6 3/6 24 in. 1/8 each. 4051 Syphon, with safety bulb and trap, to prevent the liquid being drawn into the mouth, and to draw off the liquid by blowing £023 4052 Syphon, glass, plain, length of short limb 12 15 18 21 24 in. 6d. 7d. 8d. lOd. I/- each. 4053 4054 4053 Syringes, glass, best English make . . . . • 4054 Test Glasses, clear glass, cylindrical, on sole, with spout. 4055 i oz., 5d. ; 2 oz. £0 Capacity 4 6 8 12 16 oz. Price 4d. 5d. 6d. 8d. 9d. each. I) 3/9 4/6 5/9 7/6 8/6 perdoz. 4055 Test Glasses, clear glass, conical, on sole, with spout. Capacity I 2 4 6 8 12 OZ. Price 3d. 4d. 4d. 5d. 64. 8d. each. ** 2/6 3/6 3/9 ya\ 4/6 5/9 7/6 per doz. {&%?„* |H 14 • CROSS STREET wl— \ IL_ _ W. • HATTOTST 3 GARDE1ST, ~ Mil' /i Ex-V • 1 • 11 /]( 762 BAIRD &.TATLOCK: (LONDON) LTD. ~ 4056-4057 4058 4059 56 Test Tubes, best quality, suitable for bacteriological and chemical use. Length 2223344445556 in. Diameter ifttilliiltlt.. Price . . 3d. 3d. 3d. 3d. 3d. 4d. 5d. 6d. 8d. 6d. 6d. 7d. 6d. per doz. . . 2/3 2/6 2/6 2/6 2/9 3/6 4/9 5/6 7/6 5/6 5/6 6/6 5/6 per gross. Length . . 6 6 6 6 7 7 7 88 3 9 10 12 in. Diameter .. f I/ I I * xi Ji J Jl x£ Ji xi * .. Price .. 7d. 8d. I/- I/- 1/2 1/9 2/- 1/6 2/- 2/6 2/9 3/- 3/- per doz. - — — per gross. 6/- 7/6 ll/- ll/- — — — ——— — ^57 Test Tubes, second quality, suitable for schools, etc. Length . . . . • • 5 5 < Diameter Price 6 I 5/3 ..3/9 4/6 4/6 458 Test Tubes, without rims, for bacteriological work, best quality. 6by| 6 , 8 in. i it „ 8/- 18/- per gross. Size Price 6 by J in. 6/- 7/6 per gross. 459 Test Tubes, with rims, extra strong, for bacteriological work, best quality. Size . . . . . . 5 by f 6 by f 6 by f 7 by J in. Price . . . . . . 7/6 9/- 10/- 12/- per gross. 460 Test Tubes of " R " Resistance Glass, stout, suitable for bacteriological work. Size . . . . . . . . . . . . 5 by | 6 by f Price . . . . . . . . . . . . lid. 1/1 per doz. 9/- ll/- per gross. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 763 BAIRD .kTATLOCK. (LONDON) LTD. i 11 0 4061 4062 4063 4064 4068 4069 4061 Test Tubes, graduated, of best quality Resistance glass. Capacity . . 5 I0 Graduated in J 1 Price .. .- •• • 6d. 8d. 5/6 7/6 15 i lOd. 9/6 20 C.C. £ C.C. I/- each. 11/6 per doz. 4062 Test Tubes on feet, graduated and figured with one mark, Resistance glass. Capacity Price i 2 4 5/- 5/6 61- 5 6/6 10 C.C. 7/- per doz. 4063 Test Tubes, on sole, best quality, clear glass. Size Price • • 2 by f 3 by \ 4 by J .. I/- 1/2 1/3 5 byf 1/6 6 by i in. 2/- per doz. 4064 Test Tubes, nested, in cardboard cases. Nest of Price 6 5d. 3/9 9 lOd. 12 1/6 per nest. 15/- per doz. nests. 4065s Test Tubes with rim, new Jena Thin Laboratory Glass. Size Price 4by£ 5 byf 5 by f 6 by f 8d. lid. 1/1 1/1 6 byf 1/4 6 by i in. 1/11 per doz. 4066s Test Tubes with rim, of new Jena Stout Combustion Tubing, for heating dry substances, e Size .. 4byJ 5 by f 5 by f 6 by f 6 by f 6 by i in. Price .. 1/4 1/10 2/2 2/2 2/8 3/10 per doz. 4067 Test Tubes, of hardest glass for cordite heat test, specially made to meet the requirements of the Government specification, with three marks per doz., 4/6 ; per gross £2 10 4068 Test Tube Baskets . . . . . . each, 7d. ; per doz. 4069 Test Tube Brushes, on tinned iron wire, with bristle or sponge ends each, 2d. ; per doz. 4070 Test Tube Brushes, on tinned iron wire, with bristle ends, second quality each, Id. ; per doz. 4071 Test Tube Brushes, on copper wire, best bristles 4d.; £069 £0 1 9 £0 1 0 £039 CROSS STREET • HATTCTSr GARDETST, E-C 764 BAIRD &TATLOCK (LONDON) LTD. 4073 4074 4075-4076 )72 Brushes for Tubes, bristles in centre. Size Price 30 3d. 2/9 4077 36 in. 5d. each. 4/6 per doz. )73 Test Tube Cleaners, with indiarubber ends for use with tubes up to i in. diameter each, 3d. ; per doz. £029 )74 Bottle Brushes, best bristles, on stout copper wire. Size of bristle head . . . . . . 2\ by 2 Length of handle . . . . . . 12 Price .. .. .. .. 8d. )75 Burette Brushes, on copper wire, best bristles )76 Burette Brushes, tinned iron wire. Size Price )77 Brushes, of fine glass bristles 15 lOd. 30 6d. 5/6 4 by 3 in. 18 „ I/- each. each £013 36 in. 7d. each. 6/6 per do?. each £010 4078 )78 Brushes, camel hair. Size Price No. 7 (Small) 6d. )79 Brushes, camel hair, flat, tin bound. Width Price 3d. 2/9 4079 No. 3 (Medium) 9d. i id. 3/6 i 5d. 4/6 No. i (Large) I/- per doz. 6d. 5/6 2 in. 9d. each. 8/6 per doz. jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 765 BAIRD &TATLOCK (LONDON) LTD. 4080 4080 Brushes/camel hair, round (dabbers) (illustrations are full size). Size 'No. .... . . i 3 5 Price .. .. .. 2d. 3d. 4d. 1/6 2/6 3/6 6d. 5/6 7d. each. 6/6 per doz. 4081 4082 4083 4081 Test Tube Holders, wood . . . . . . 4082 Test Tube Holders, brass, in wooden handle 4083 Universal Holder or Clip, for test tubes, basins, crucibles, etc. 4083 each, 2d. ; per doz. £0 1 ,. 7d. ; „ £0 6 I/-; £011 CROSS STREET • HATTOTST GARDETST, 766 RAIRD &.TATLOCK (LOM)ON) LTD. Thermometers of Finest English Manufacture To reduce Centigrade degrees to Fahrenheit, multiply by 9, divide by 5, and add 32. Example 20° C < 9 -f 5 + 32 = 68° F. To reduce Fahrenheit degrees to Centigrade, subtract 32, multiply by 5, and divide by 9. Example 104° F - 32 X 5 -r 9 = 40° C. THERMOMETRICAL EQUIVALENTS. Cent. Fahr. 3I5.550 180° 260° 150° 204.44° 100° 149° 60° 130° 32° Fahr. 600° 500° 400° 300° 266° 212° = IOOC CERTIFICATE- OF EXAMINATION C«atler»d« ThtraoiMtvr /V0 13Z38 bird 4 Tttlook (London) Ltd. Corrtcntnt (t* tl* ntartti 0« ) to k applud n th RtmJmgt, dttermmtd by com far u ft -u/irh tht Standard f/utr*mr*tj of Vbc ^Rtitnol flhijiutl 1U.C.K CHIKIW tU 500° C. and 900° F., are made of Jena Borosilicate glass with enamelled back, above these ranges of Jena Combustion glass with ground back. BAIRD &TATLOCK: (LONDON) LTD. 4091 4091s Thermometers, Standard " E," of Jena normal glass, in sets of seven instruments covering the range o° to 360° C., about 55° C. on each thermometer. The instruments showing above 100° C. filled with nitrogen gas and provided with zero point graduations. Length 12 in. No. Range Price No. Range Price — 5° to 50° C. in*0 13/6 45° to 105° C. in y 15/6 100° to 155° C. in 211- 150° to 205° C. in 1° 21f- 200° to 255° C. in 1° 24/- 250° to 305° C. in y 251- 300° to 360° C. in ic 26/- 4092s The above set complete in morocco case, £7 10 0. 7 10° 4093s If required with National Physical Laboratory Certificate, the extra cost will be : — Thermometer No. . . i 2 3 4 5 6 N.P.L. Certificate every . . 10° 10° 10° 10° 10° 10° Price SI- 5/- 6/6 6/6 8/- 8/- 9/- 4094s Price complete with Certificates, £9 18 0. 4095s Thermometers, Standard " E," of Jena glass, but in four thermometers covering from o° to 400° C., the last three instruments being filled with nitrogen gas and provided with zero point graduations. Length, 14 in., subdivided in £°. No. 1234 (Borosilicate glass) Range - 5° to 105° C. 95° to 205° C. 195° to 305° C. 295° to 405° C. Price 16/- 25/- 27/- 30/- The above set complete in morocco case, £5. If required with National Physical Laboratory Certificate, the extra cost will be :•— Thermometer No. . . . . . . . • I 2 3 N.P.L. Certificate every . . . . . . 10° 20° 20° Price .... 7/6 8/- 9/6 A4095 Price complete with Certificates, £6 14 6 4 20° 9/6 CROSS STREET • HATTOTST GARDE1ST, E-C 770 BAIRD &T&TLOCK (LONDON) LTD. 4096 40965 Thermometers, Standard " E," of Jena glass, but in four thermometers covering from o° to 400° C., the last three instruments being filled with nitrogen gas and provided with zero point graduations. Length, 18 in., subdivided in £°. t No. i 2 34 (Borosilicate glass) Range -5° to 105° C. 95° to 205° C. 195° to 305° C. 295° to 405° C. Price £150 £1 12 0 £1 14 0 £1 18 0 The above set complete in morocco case, £612 6. 4 10° 14/6 If required with National Physical Laboratory Certificate, the extra cost will be- No. ... .. .. .. .. i 2 3 N.P.L. Certificate every . . . . . . 10° 10° 10° Price .. .. .. .. .. 7/6 10/6 14/6 Price complete with Certificates, £8 19 6. The sets quoted can be supplied graduated in Fahrenheit scale in i° and i° corresponding to the Centigrade 4° and |°, at the same prices, and can also be supplied graduated in £° F. and -j^" C. at extra charge in proportion. NOTE RE THERMOMETERS WITH ZERO POINT GRADUATIONS. At normal temperatures the enlargement in the bore is partly filled wiUi mercury. Should small particles become separated in transit or handling, as sometimes occur, the thermometer should be carefully heated till the mercury re-unites, which it will readily do provided the separated particle of mercury has not closed the upper end of the enlargement against the passage of the enclosed nitrogen gas. In such case the mercury must first be dislodged by tapping the bulb or by using greater heat to cause the mercury to unite in the chamber at the top end of the bore. If preferred, these thermometers can be provided with graduations at about 15° or 20° C. instead of at o°, by this means the mercury at normal temperature is in the capillary below the enlargement, and the risk of separa- tion reduced to a minimum. When heating the bulb of Standard Thermometers the precaution should always be taken to place the bulb inside a small test tube to avoid contact with the flame. 4097s Thermometers, Standard " F," of Jena normal glass, nitrogen filled, and annealed to avoid any serious change of zero, length about 12 in. The thermometers are good quality, and would pass the National Physical Laboratory, but are not of the standard accuracy of Thermometer Standards A to E. Range Or Price Extra cost of N.P.L. Certificate at every 50° C. or 100° F. . . o° to 200° C. in i° 30° to 400° F. in i° IB/. o° to 250° C. in i° 30° to 500° F. in 2° 15/- 61- o° to 300° C. in i° 30° to 600° F. in 2° I8/- 91- 771 BAIRD &. TATLOCK (LONDON) LTD. i8in. - 5° to 105° C. 15 in. -5°to5o°C. i8in. -5°to50°C. F F A° 24/- 16/- 18/- 7/6 51- 5/- 15 in. i8in. 50° to 105° C. 50 to 105° C. F i ° Tff 17/6 211- 4098s Thermometers, with enclosed milk glass scale, Standard " G," scale fused to the outer sheath by a special joint, Centigrade scale. Length Range Subdivided in Price N.P.L. Certificate at every 10° C. to nearest 0.05° C., extra Length Range Subdivided in Price N.P.L. Certificate at every 10° C. to nearest 0.05° C., extra . . 5/- 5/- Above thermometers have bulbs of Jena normal glass, and are annealed to prevent zero changes. 4099s Thermometers, with enclosed milk glass scale, similar to above but second grade, Centigrade scale. Length 16 in. 12 in. 16 in. 12 in. 16 in. Range ' o° to 100° C. o° to 100° C. o° to 50° C. o° to 50° C. 50° to 100° C. Subdivided in i -| TV £ ^ Price 10/6 9/- 10/6 9/- 10/6 Length 12 in. 16 in. 12 in. Range 50° to 100° C. 100° to 150° C. or 150° to 200° C. 100° to 150° C. or 150° to 200° C. Subdivided in ^ T\j ^ Price 9/- 15/- 12/- Brass Cased Thermometers for Pipes and Tanks, with scales ranged 3^5° F., -£&s° F., 78sV F., or equivalent Centigrade, stems 6 inches long. Any ordinary range of scale made to order at same prices. For ranges higher than 600° F. prices can be quoted on receipt of particulars. Straight Thermometers, for attachment to pipes. ° F., Silvered Metal Scales. Opal Scale extra. Single Cover. Revolving Cover. 4100s 8 in. cover, base screwed | in. or f in. gas 4101s 10 in. „ „ 1 „ i „ 4102s 12 in, ,, large size f „ i „ 17/6 191- 22/6 22/- 25j- 30/- 21- 2/- 2/6 4100-4102 Length of stem according to diameter of pipe, which must always be stated when ordering. If stem is required longer than 6 in., 4/- per foot extra. Bases screwed to special sizes to order. 4103s Screwed Sockets for soldering to pipe for thermometer to screw into. For 8 in. and 10 in. size, 1/6 extra. 12 2/6 14- -CROSS STREET • HATTOTST GARDEN, E-C 772 BAIRD &TATLOCK (LONDON) LTD. 4104 4105 Front view of 4104 and 4105 4104s Elbow Right Angle Thermometers, with flange, for fixing to tanks, either single or revolving cover. Standard Silvered Metal Scale. Length Opal Scale from Extra. Flange. Single Cover. Revolving Cover. 8 in. cover, small size 3i in. 261- 30/- a/- 10 in. ,, medium size 4 in. 34/- 38 /- a/- 12 in. „ large size 5 m. 45/- 4,9}- a/i 4105s Elbow Right Angle Thermometers, with screwed shank and back nut to tighten up inside the tank, either single or revolving cover. Standard Silvered Metal Scale. Length Opal Scale from Extra. Flange. Single Cover. Revolving Cover. 8 in. cover, small size 3*in. 27/6 31/6 a/- 10 in. ,, medium size 4 in. 36/- 40/- a/- 12 in. ,, large size 5 m. 47/6 52/- 2/6 Thickness of tank should be mentioned when ordering. Also made with separate fittings and union connection for attachment to pipes. Prices on application. Length of stem can be made up to 6 in. at the same prices. If stem is required longer than 6 in., 4/6 per foot extra. Length of covers in all cases is length A to B on sketches. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS, f 773 BAIRD &TATLOCK. (LONDON) LTD. 4106 4106s Thermometers, high temperature, for use in works, etc., graduated to 550° C. or 1,000° F. The tubes are made of Jena glass, nitrogen filled, and are fitted in steel sheaths, drilled at bottom to allow free access of liquid to the thermometer bulb. The scales are of opal glass, protected by brass half-tube, and on top of this a ring is fixed for suspension, scale 10 inches long. Length over all . . . . 3 4 5 ft. Price . . . . ..£220 £280 £2150 each. 4107= Thermometers, high temperature, as above, but scale protected by revolving brass cover 10 in. long. Length over all . . . . 3 4 5 ft. Price .. .. .. ..£270 £2 13 0 £300 Thermometers Nos. 4106 and 4107 are graduated for stem immersion to 2 ft., 3 ft., and 4 ft. respectively. g'l'g'S'8 i'S'j 4108 4108s Standard Thermometers, 30 to 220° F., engine divided on stout silvered brass scale, with figures on raised piece at side, in morocco case, with National Physical Laboratory certificate . . . . . . . . . . . . . . . . £2 5 t 4109s High Temperature Thermometers, mercurial, Jena glass, filled with nitrogen under pressure. Length .... 15 15 16 18 18 in. Range . . . . 360° C. 400° C. 450° C. 500° C. 550° C. Price .. .. 4/- 5/6 10/6 * 15/- 18/- each. Any special range or length made to order. 4110" Engraved English Chemical Thermometers, accurately made, engraved scale, but without certificate, length about 12 in. . . . . 30 to 220° F. . . . . single Range Divided into Price Range Divided into Price o to 110° C. single 30 to 400° F. every two 6/- o to 200° C. single 6/- 30 to 600° F. every two degrees. 7/- each. o to 300° C. every two degrees. 7/- each. 4111s Thermometers, Jena glass, for cold mixtures and liquid air, etc., milk glass scale, + 30° C. to —120° C. in single degrees, toluol filled. . .. .. .. .. each £0 18 C 4112s Ditto, +30° C. to -200° C., pentane filled . . . . „ £1 13 f 4113s Thermometers, Jena glass, for cold mixtures and liquid air. Set of 10 range o to minus 200° C. divided in TV° £27 10 (. CROSS STREET • HATTCTST GARDETST, E-C 774 BAIRD &.TATLOCK (LONDON) LTD. 4114 4114 Thermometers for chemical work, of English glass with Jena bulbs, engraved scale, length about 12 in. .correct to within half degree at lower ranges and one degree at higher ranges. Best English manufacture in metal cases, nickelled. with pull off covers. A. B. C. D. E. F. Range o to 110° C. o to 220° C. o to 360° C. o to 220° F. o to 400° F. o to 600° F. Price 4/6 4/9 6/- 4/6 4/9 6/- 52/- 551- 70!- 52/' 55/- 70/-perdoz. Special prices for quantities. NOTE. — These thermometers are not of standard quality or suitable for verification at the National Physical Laboratory, but are specially adapted for general chemical work in place of the ordinary Continental made thermometer. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 775 BAIRD T GARDETST, E-C 790 BAIRD &TATLOCK (LONDON) LTD. » 4190 4191-4192 4193 4195 4190 Thermometers, bath, cased in wood, range 20° to 130° F. Length . . . . . . . . . . 6 8 Price .. .. .. .. .. 6d. 8d. 5/6 7/6 4196 12 m. I/- each. ll/- per doz. Thermometers, brewers', in japanned tin or copper case, tubes with enamelled back, best English make, 30 to 220° F. Length .. .. .. .. 8 4191 Japanned tin case 4192 Copper case 1/9 2/6 10 2/3 12 3/3 14 in. 3/6 each. 4/9 „ 4193 Thermometers, brewers', extra stout scale 30° to 220° F., in rivetted copper case, with scoop. Length . . . . . . . . . . 10 12 14 in. Price .. .. .. .. .. 9/- ll/- 12/6 each. 4194 Thermometers, as fig. 4193, porcelain scale 40 to 80° F., copper case. Length of case . . . . . . . . . . 12 Price .. .. .. .. .. .. 12/- 4195 Thermometers, malt kiln, zinc scale on pointed zinc shod oak frame . . 14 in. 13/6 each. each £080 4196 Thermometers, malt kirn, round oak stick, brass stem, registering maximum, graduated to 240° F. .. .. .. .. .. .. each £0 16 0 See Meterological Section, for Maximum and Minimum Thermometers, Thermographs and Hygrometers, etc. BAIRD &L TATLOCK. (LONDON) LTD. j _ 4197-4199 Benzol and Naphtha Thermometers, best English make. It is well known that with commercial benzols, distilling at the same uniform rates, different thermometers of admitted accuracy do not indicate the same quantity of fluid distilled. This result, which may give rise to serious inaccuracy in returning trade certificates, is mainly due to differences in the dimensions in the ther- mometers, either in the bulb, the bore or the length of stem. We may perhaps be allowed to remind users of the exact position in \vhich the thermometer should be placed : A 200 c.c. retort should be used, the thermometer inserted in the tubulure so that the distance between the bottom of the retort and the bottom of the bulb is f inch. The 70° mark on the thermometer should then be clear of the cork in the tubulure. One degree Cent, should be deducted or added for each inch on the barometer below or above 30 inches. 4197s Benzole Thermometer, 14^ in. long, divided and figured on the stem from about 70° to 130° Centigrade. A. In fifths of a degree . . . . . . . . . . . . ..£017 B. In tenths of a degree . . . . . . . . . . . . ..£12 4198s Toluol Thermometer, 14^ in. long, divided and figured on the stem from about 100° to 165° Centigrade. A. In fifths of a degree . . . . . . . . . . . . ..£017 B. In tenths of a degree . . . . . . . . . . . . ..£12 4199s Naphtha Thermometer, 14$ inches, engraved on stem, 90° to 200° Centigrade, in half degrees . . . . . . . . . . . . . . . . £0 17 Other ranges of temperature quoted for on receipt of particulars. 4204 8 4201 4202 4203 4201 Tiles for Comparing Colour, white glazed on both sides. 246 4d. 6d. 8d. I/- 3/9 5/6 7/- ll/- 4202 Tiles, Royal Berlin Porcelain, oblong, twelve depressions, size 4^ by 3^ in. . . 4203 Tiles, Royal Berlin Porcelain, biscuit, for arsenic testing, size 4 by -z\ in. 4204 Tiles, Royal Berlin Porcelain, oblong, with hole, size 8 by 6 in. , white glazed one side 4205 Palettes, white stoneware, glazed both sides, 9 by 6 in., with thumb-hole 12 in. square 2/- each. 23/- per doz. each £0 £0 £0 £0 1 0 9 3 0 1 3 CROSS STRET • HATTOTST GARDEN, E-C 792 BAIRD &TATLOCK (LONDON) LTD. 4206 4209 4206 Absorption Mats, of compressed paper, making a good substitute for porous tiles, size ii centimetres diameter by 4 millimetres thick, each mat will absorb about 30 cubic centimetres of water . . . . . . . . . . per 100, 2/- ; per 1,000 £018 0 4207 Tiles, porous, for drying crystals, 6 in. square 4208 Porous Soup Plates, for drying crystals, 8 in. diameter 4209 Porous Saucers, for drying crystals, 5j in. diameter . . per doz. £040 £020 £0 1 3 Lovibond's Tintometer Sets (Descriptive Pamphlet on application.) 4210 4210s Tintometer Set No. 1. — For Dyers and Printers, applicable to liquids and solids, including the improved optical instrument, five vulcanite and five silvered cells from i in. to -j^g- in., one capillary film holder, trays and presser for powders, six blocks with pins for fabrics, standard white, without standard glasses, polished box with stand and reflector . . £8 18 0 4211s Tintometer Set No. 2. — For Fabrics and Solids only, including the improved optical instrument, box with stand and reflector, trays, blocks, presser, standard white, without standard glasses . . . . . . . . . . . . . . . . £4 4 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 793 BAIRD &TATLOCK (LONDON) LTD. 4212s Tintometer Set No. 3a. — For Brewers, Maltsters, Sugar and Caramel Manu- facturers, Wine and Spirit Merchants, including the improved optical instrument, box with stand and reflector, i in. and ^ in. silvered cells, filtering apparatus, and twenty standard glasses, series 52 and 50 .. . . . . . . . . . . £650 Extra apparatus for estimating the colour of dry malt, thirty -three standard glasses, with trays, presser, and standard white .. .. .. .. .. .. £2 18 0 4213s Tintometer Set No. 3b.— For Brewers and Maltsters, including monocular instrument, stand box, reflector, i in., 2 in., and 3 in. brass cells, and fifty-three equivalent standard glasses .. .. .. .. .. .. .. .. .'.£900 4214s Lamps for testing Beers and Malts by artificial light (No. 3c). .. .. .. £110 4215s Tintometer Set No. 3c. — For Wine and Spirit Merchants, including the improved optical instrument, box with stand reflector, 2 in., J in., \ in., and TV in. silvered cells, and ninety standard glasses . . . . . . . . . . . . . . £10 10 0 This number of glass is found sufficient for the ordinary brands of ports, sherries, and clarets. 4216s Colour Recorder. When sixteen standard colours are sufficient they are arranged on a wheel for facility of working ranging from palest (new spirit) to darkest (full golden) . . £500 4217s Tintometer Set No. 4. — For Estimating the Colour in Water, including the monoc- ular optical instrument, box with supports and reflector, 2 ft. and I ft. brass cells, without standard glasses .. . . . . . . . . . . . . £6 12 0 4218s Tintometer Set No. 5a. — For Estimating Percentage of Ammonia, in Nessler's ammonia test, including the improved optical instrument, box with stand and reflector, | in. glass cell, with thirty standard glasses . . . . . . . . ..£600 4219s Tintometer Set No. 5b. — For Estimating Carbon in Steel, including the improved optical instrument, box with stand and reflector, | in. glass cell, and thirty-four standard glasses, series 52, and twenty-six glasses series 50 .. . . . . . . . . £800 4220s Tintometer Set No. 6a.— For Estimating the Colour in Oils, Waxes, Lards, and other Fats, Varnishes, Gelatine, Scale, and other similar substances, including the improved optical instrument, fitted with hot-water apparatus for melting solids, with thermometer for taking their melting point, box, i in., | in., J in. silvered cells, without standard glasses . . . . . . . . . . . . . . . . £6150 4221s Tintometer Set No. 6b.— For Estimating the Colour in Cotton Seed Oil, including the improved optical instrument, fitted with lamp and hot-water apparatus for liquefying the oil and maintaining a given temperature, 5j in. cell, and thirty-six standard glasses £9 10 0 4222s Tintometer Set No. 7. — For Standardising Merchantable Petroleums, including the monocular optical instrument, box with stand and reflector, 18 in. cell (silvered), four special standard glasses for water white, standard white, superfine white, and prime white £5 10 0 Additional apparatus for intermediate, Russian, and lubricating oils, containing^ in. silvered cell and five additional standards . . . . . . . . . . . . £1 12 '0 4223s Tintometer Set No. 8. — An Investigator's Laboratory Set for all purposes, including the monocular optical instrument, in plain box, with stands and reflector, 24 in. and 12 in. brass cells, 2 in., i in., \ in., j in., \ in., ^ jn. silvered and i in., | in., \ in., \ in., TV in. vulcanite cells, one capillary film holder, six blocks, six trays, presser for powder, standard white, shoe for opaque work, and filtering apparatus, without standard, glasses £13 13 0 4224s Tintometer Set No. 9. — For Estimating the Value of Flour, including the improved optical instrument, standard white, six trays, pressing apparatus, and ninety standard glasses 4225s Tintometer Set No. 10. — For Estimating the Colouring Matter in Tanning Solu- tions, consisting of binocular instrument in polished box, with stand and reflector, .5 centimetre and i.o centimetre glass cells, and 88 standard glasses 4226s Tintometer Set No. 11. — For Estimation of the ordinary 1 in. cubes of Resin £10 10 0 £10 15 0 £440 14- -CROSS STREET- HATTCW GARDEN E-C 794 BAIRD &TATLOCK (LONDON) LTD. 4227 4227" Tintometer No. 17.— Pigmentation Meter (Mr. Gray's suggestion). An anthropological instrument for registering the colour of the hair, eyes, and skin for racial classification. Instrument alone, £1 1 0. Special hair and eye standards (ten), 3/- each. Set of fifty standard colours for hairs, eyes and skins, £5 0 0. Complete set of apparatus, and box to contain same £8 16 6 4228 4228s Tintometer No. 12.— Educational Set or Colour Educator. An apparatus for teaching colour in schools, consisting of a frame with six apertures for the standard glasses, twenty-seven standard colours, white plate for dealing with opaque colours, coloured diagrams for illustration, and handbook of instruction . . . . . . £1 1 0 4229s Tintometer No. 13. — Colour Blind Set, consisting of an upright frame pierced with eight apertures for testing the vision for transparent colours, and a white table top for opaque colours. The standard consisting of thirty-two simple and compound colours, are arranged in two trays ; also card of instructions and chart for classifying the results of the examination . . . . . . . . . . . . . . ..£550 1230s Tintometer No. 14. — Colour Top, for demonstrating and measuring the effect of definite mixtures of coloured light . . . . . . . . . . . . . . £2 10 0 Discs for use with the above . . . . . . . . . . . . each £050 1231s Tintometer No. 15. — Smoke Density Tester, consisting of an optical instrument with two apertures, one for viewing the smoke, the other being intercepted by the standardised smoke glasses .. .. .. .. .. .. ..£220 T232S Tintometer No. 16. — Fog Density Tester. An instrument for measuring fog densities and luminosities of lower intensities than daylight. The apparatus consists of an optical instrument on stand, a lamp for the standard light, a reflector and ninety standard glasses in box . . . . . . . . . . . . . . £13 5 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 795 BAIRD &TATLOCK (LONDON) LTD. 4234s Tintometer No. 18. — The Chromo-Pyrometer, for temperatures of incandescent furnaces of metals. Price with one temperature . . . . . . . ; ..£55 Additional degrees . . . . . . . . . . . . . . each £0 5 4235s Tintometer, as recommended by Prof. H. R. Proctor and Dr. J. Gordon Parker, and adopted by the International Association of Leather Trade Chemists as the standard method of measuring colour in extracts and tanning materials. Instructions, using the Standard ol half per cent. Solution of Tanning Matter in 1 centimetre Cell. The apparatus consists of the binocular tintometer, in polished box with stand and reflector, 0.5 centimetre and i centimetre glass cells, and 88 standard glasses, 33 of red, 30 of yellow, 20 of blue, and 5 colourless. To ascertain the colour the following method is adopted : — The required quantity of extract previously calculated, according to analysis, is weighed into a 500 cubic centimetre flask, and made up with boiling distilled water to 50 cubic centimetres ; the solution is then allowed to cool, after which it is filtered and measured in a centimetre cell in the tintometer in the usual manner. NOTE. — Although perhaps theoretically not always quite accurate, it is a considerable saving of trouble, and also of avoiding the errors of making and filtering a fresh solution, to make the colour measurement on the solution made for analysis, containing about 0.4 grain of tanning matter penoo cubic centimetres, and to reduce the results to half per cent, by dividing by the actual strength and multiplying by 0.5. Complete price . . . . . . . . . . . . . . . . £10 15 Accessories for Lovibond's Tintometer. Silver Plated. 4236s Metal Trough, gauged 2-ft. with glass ends 30/- 4237s „ gauged i8-in. . . 27/6 4238s ,, gauged 12-in. . . 25/- 4239s ,, gauged g-in. . . 22/6 4240s ,, gauged 6-in. „ 20/- 4241s ,, gauged 3-in.' . . 18/- Glass or Vulcanite. 4242s ,, gauged 2-in. IS/- 10/- 4243s ,, gauged i-in. „ 12/6 9/- 4244s ,, gauged £-in. ,. 10/6 8/- 4245s „ gauged J-in. 10/6 8/- 4246s ,, gauged J-in. 10/- 8/- 4247s „ gauged tV-in- 10/- 8/- 4248s Capillary Film Holder, with platinum gauges from /ff to ^ of an inch thickness . . . . £10 0 4249s Standard Coloured Glasses each £0 2 0 NOTE. — The price of even numbers, when ordered without apparatus, fractional intervals in sets will be or out of sequence of the each £0 3 „ 4250s A Complete Set of Standard Glasses for matching all colours, 470 glasses .. .. £47 0 0 4251s Mounted Lens for equalising uneven surfaces £01 6 4252s Diaphragms for reducing the aperture in special cases each £0 1 0 4253s Trays for powders, and Blocks for fabrics . . £00 6 to Iff 14 • CROSS STREET • HATTON GARDEN, E-C- J 1 796 BAIRD &TATLOCK (LONDON) LTD. 4261* 4262* 42631 " Presser " for pressing powders evenly into trays Strong Pins for fabrics Filter Apparatus and packet of filter paper Thermometer for taking the melting-points of fats, waxes, etc. Pure Plaster of Paris for white background Strong Polished Box to contain sets Metal Cages to hold standard glasses in instrument TEXT BOOKS ON TINTOMETER. " Measurement of Light and Colour Sensations." By Joseph W. Lovibond .. " An Introduction to the Study of Colour Phenomena." By Joseph W. Lovibond . . " The Teachers' Handbook of Colour." By Joseph W. Lovibond .. each . . per doz. . . per oz. from 10/6 to each 4264 4264s Tintometer, Veley's, mounted on stand, as illustrated DESCRIPTION. The apparatus consists of a base board, on to which are fastened two wooden uprights at a distance 8.8 centimetres apart, and also a metal rod with adjusting screw. Two plane mirrors are attached to the upper and lower ends of the uprights, the position of which, relative to the horizon, can be adjusted by means of the screws. A metal screen on the upper part of the uprights serves to cut off extraneous light from the top mirror. Between the two mirrors is the tintometer box divided into two compartments by a wooden partition, on which a wooden scale is fastened ; in each of the compartments is placed a glass cylinder to contain the solutions, the tints of which are to be compared ; the level of liquid in the right-hand cylinder, with side piece, can be varied by raising or lowering the glass vessel connected with the cylinder by flexible tubing, the fine adjustments being made by the screw. Holes in the upper and lower framework of the box serve for the insertion of a thermometer. It is advisable to take all the readings out in turns of lengths of movable columns of liquid, or to draw up a table of corrections. For daylight working a window facing north is preferable ; for artificial light either a 16-32 candle electric lamp with silvered back, or a Nernst lamp, both being enclosed in box open on one side only, may be used. The apparatus is suitable for nesslerisation, analysis by indicator, spirit analysis, comparison of beer-worts, and generally of any turbid or coloured liquids. £0 £0 £0 £0 £0 £1 10 £0 1 £0 £0 £0 7 5 0 6 6 0 0 6 0 6 6 6 6 £2 15 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 797 BAIRD &TATLOCK (LONDON) LTD. 4265 4265 Tongs, crucible, malleable iron, lacquered, bow shaped. Length Price ,, . . . . . . • • • • 4266 Tongs, crucible, malleable iron, lacquered, without bow. Length Price 4267 Tongs, polished gun-metal, without bow, as Fig. 4266. Length . . . . . . . . 6 Price .. .. .. .. I/- H/6 4268 4268 Tongs, crucible, polished gun -metal, best finish, with bow. Length . . . . . . . . 6 7 Price 1/2 1/3 13/- 14/- 4266 • • 6 7d. 8 in. 9d. each. 8/- per doz. • . 6 5d. 4/6 8 in. 7d. each. 6/6 per doz. 7 1/3 13/- 8 1/4 15/- 10 in. 1/10 each. 21/- per doz. 4269 Tongs, crucible, polished gun-metal, nickel-plated, bow shaped, 8 in. 8 10 in; 1/5 2/- each. 16/- 22/- per doz. each £020 4270 4270 Tongs, crucible, gun-metal, 8 in., with platinum shoes fitted, price variable 4271 Tongs, crucible, pure nickel, with bow, as Fig. 4268. Length Price 6 3/7 4272 Tongs, crucible, pure nickel, 8 in., with platinum shoes, price variable 4273 Tongs, for picking up mercury globules 4273 about £0 15 6 8 in. 5/- each. about £0 19 6 each £026 CROSS STREET • HATTOTST GARDE1ST, E-C BAIRD &.TATLOCK (LONDON) LTD. 4274 4274 Crucible Tongs or Forceps, strong steel, nickel-plated, length 6J in. 4277-4279 4275 Tongs, crucible, polished iron, 18 in. long, bow shaped 4276 Tongs, crucible, polished iron, 18 in. long, straight each, 1/3; per doz. £014 0 each £030 £029 4277 Trays, white stoneware, 9^ by 2} in., with rim, to hold three 6-oz. acid bottles on reagent shelves . . . . ' . . . . . . . . . . . . each £013 4278 Trays, white stoneware, gj by 3^ in., with rim, to hold three 8-oz. acid bottles on reagent shelves . . . . . . . . . . ... . . . . each £016 4279 Trays, white stoneware, 12 by 3^ in., with rim, to hold three r6-oz. acid bottles on reagent shelves each £019 4282 4283 4284 4280 Triangles, iron wire, ordinary 4281 Triangles, iron wire, thicker make 4282 Triangles, malleable cast-iron, for heavy crucibles, etc. Size of triangles . . . . . . ij Price .. .. .. 2d. 1/9 4283 Triangles, iron wire covered with pipe-clay, 2, 2\, and 3 in. 4285 .. per doz. £010 each, 2d. ; £019 2 2id. 2/3 4284 Triangles, of pipe-clay, designed by Professors Clowes and Coleman. Size of triangles Price A42845 Triangles, of nickel-chrome wire. Size of inscribed circle 22 I/- 2 3d. 2/6 32 1/3 3d. 2/6 2* 3d. 2/6 3 m. Oil. each. 5/6 per doz. per doz. £013 3d. each. 2/6 per doz. 44 mm. 1/6 each. 4285s Triangles, iron wire, platinum wire triangle inside, price about each £050 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 5*5' 799 BAIRD &L TATLOCK (LONDON) LTD. i 4286 4287 4286 Tripods, triangular tops of malleable iron, height 8 in. 4288 4289 each, lOd. ; per doz. £096 4287 Tripods, second quality, with cast-iron triangular top, 7 in. legs riveted to top, 5 in. triangle each, 7d. ; per doz. 4288 Tripods, round top of malleable cast-iron, height 8 in. Diameter inside at top Price 4289 Tripods of glass rod, for Desiccators, etc. Side of triangle Height Price £066 4 5 6 7 8 in. 9d. lid. I/- 1/4 1/6 each. 8/6 10/- 111- IS/- 17/- per doz. c. i* 2 2* 3 in. . . i* 2 2j 3 in. 4d. 5d. 6d. 7d. each. 3/6 4/6 5/6 6/6 per doz. 4290 4292 4290 Quadrupeds, with cast-iron top, and legs 8 in. high riveted to same. Top, outside measurements . . 5 by 5 6 by 6 8 by 8 10 by 10 in. Price .. .. .. 1/9 2/- 2/6 3/- each. 4291 Quadrupeds, with cast-iron top, and legs 12 in. high riveted to same, to suit burners for petroleum, No. 3457 Top, outside measurements . . 5 by 5 6 by 6 8 by 8 10 by 10 in. Price 2/- 2/3 2/9 3/3 each. 4292 Tripod Stand, cast-iron, for use with oil stoves, lamps, etc. . , each £0 5 CROSS STREET • HATTOTSr GARDETST, E-C 800 BAIRD &TATLOCK (LONDON) LTD. 4293-4296 Geometric Tripod Stands. These stands, designed by Mr. C. V. Boys, F.R.S., are especially adapted for supporting pieces of apparatus, such as galvanometers, lamps, etc. By their means a stand of any desired height may be made, each tripod making geometric contact with the one immediately below it. A triangular groovS is formed on the upper surface of the tripods into which the levelling screws of an instrument may be placed. The stands are supplied in two sizes : — Small size, distance from tripod to centre of feet, 75 millimetres. 4293T Geometric Stands, set of one dozen stands consisting of nine stands 50 millimetres high, two stands 25 millimetres high, and one stand 25 millimetres, to the top of which a metal table, 170 millimetres in diameter, is fixed. Aluminium per set £0 14 0 4294T Geometric Stands, set as above. Iron .. .. .. .. .. .. £0 10 6 Large size distance from centre of tripod to centres of feet, 175 millimetres. 4295T Geometric Stands, set of one dozen stands, consisting of nine stands 76 millimetres high, two stands 36 millimetres high, and one stand 36 millimetres high, to the top of which a wooden table, 33 millimetres square, is fixed. Aluminium . . . . . . £3 10 0 4296T Geometric Stands, set as above. Iron . . . . . . . . . . ..£256 OO I 2 oOOOO 000 10 4297 (full size sections) . 4297s Tubing, Indiarubber, best quality, red. Size Nos. 123456 Bore A i A i A 1 Price 2d. 3d. 4d. 5d. 6|d. 9d. „ per ft. 2d. 2|d. 3|d. 4^d. 6d. II 7 8 9 10 i I I i 1/2 1/10 2/6 3/- . in lengths of about 60 ft. ii i in. 3/6 per ft. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 801 BAIRD &TATLOCK (LONDON) LTD. o I z OO oOO 4298 4298s Tubing, Indiarubber, best quality, fine cut sheet, black. Size Bore Price Nos. i A 2d. 3 4 T8* i 4|d. 6d. lid. per ft. 2d. 3d. 4d. 5|d. 7d. lOd. per ft. in lengths of about 60 ft. (Other sizes supplied to order.) OooOO 4299 4299s Tubing, best red, suitable for vacuum or pressure work. Size A B C D E Bore . . i mm. i 4 i TS Diameter outside 10 mm. -fg §22 Price .. I/- 8d. 9d. 1/3 1/1 F A G TTT in- 1 ,. a/-: o 4300 4301 4300s Tubing, best red, seamless, \ in. bore and stout in walls, specially adapted for bunsen burners, etc. . . . . . . . . . . . . . . per yard In lengths of about 60 ft. £020 per yard £0 1 10 4301s Indiarubber Tubes, closed one end, for fitting to the ends of stirring rods, the inlet and outlet tubes of calcium chloride tubes, etc. Length . . , . . . . . « . i i i in. Bore .. .. .. .. .. TSF i TV,,- Price .. .. .. .. .. I/- 1/3 1/6 per doz. CROSS STREET • HATTCFNT GARDETST, E-C 802 BAIRD &. TATLOCK: (LONDON) LTD. 4302-3 Tubing, flexible metallic, for gas, for connecting to Bunsens, etc. Bore .. J TV 4302 Tubing, flexible, steel turned .. 4d. 5d. 4303 Tubing, flexible, copper turned .. lOd. l/- 4304 Push on Connections . . 2d. 2d. 1 * in. 6d. I/- per ft. 1/4 1/6 „ 3d. 7d. each, extra. 4305 Tubing, flexible metallic, as used for spirit Bunsens, in 5-ft. lengths, with end connections per length 4306 4306 Tubes, combustion, Royal Berlin porcelain, glazed inside and out. Length . . . . 12 20 20 20 20 Length . . . . 12 20 External diameter i £ J$ if Internal „ $ Price .. ..4/9 7/6 9/- 9/- 26 12/- 26 I* 10/6 £046 26 in. 16/6 each 4307 4307 Tubes, Meissen porcelain, glazed inside, biscuit outside. No. . . . . . • 4 Length .. 25 External diameter Internal ,, . . . . - - • • f Price 2/9 .. 32/- 3 25 « 1 3/9 44/- 2 25 rj H 4/6 52/6 i 25 in. i| ,, ijj ,, 5/9 each. 67/- per doz. 4308 4308 Tubes, iron, closed one end by welding, for combustion. Length . . . . . . 12 Internal diameter Price v4308 Tubes, iron, open both ends 18 i 1/6 1/3 1/6 24 i 2/3 24 24 in. i ,, 3/- each. 2/3 2/6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 803 BAIRD 21. Volumetric Apparatus 1079-1087 *« 22. Anatomical Models 1088-1105 » t 23. Meteorological Apparatus 1106-1124 ,, 24.* Assay Apparatus 1125-1172 " 25.* Chemicals 1187-1246 .^-^. ,^/3£s£ft— /^>Js« fen 14 • CROSS STREET • H ATTCTN GARDETST, I-JX n W , L_JB E c ry BAIRD &1ATLOCK. (LONDON) LTD. SECTION 7. Botany, including Plant Physiology. The above illustration of Case No. 4 — the Beech — gives some idea of their beauty and method of arrangement. 4402 4402T New Series of Specimens of British Forest Trees. Each case contains leaves, flowers, fruit, and a section of timber showing the bark. Many of the specimens are dried without pressure by a special process. The cases measure yj by io£ inches, are fitted with glass fronts, and bound with strong imitation leather, two brass rings being fixed behind each so that they may be hung up. The specimens are collected, preserved, and selected with the greatest care, and in each instance are arranged in such a manner that the distinctive features of the tree are clearly shown : they are therefore specially adapted for the use of schools and museums, as well as being very suitable for private use. They will be found a permanent means of impressing on the mind the distinguishing characteristics of our British Forest trees, and are of considerable service even when fresh specimens are available. Competent teachers pronounce them to be a distinct advance on any specimens hitherto obtainable com- mercially, and we are confident that they have only to be known to prove indispensable to the teacher of botany, nature study, and woodwork. 1. Oak. 2. Ash. 3. Elm. 4. Beech. 5. Silver Birch. 6. Sycamore. 7. Hazel. 8. Hornbeam. g. Alder. 10. Lime. 11. Pine. 12. Larch. 13. Cypress. 14. Yew. 15. Hawthorn. 16. Holly. 17. Hone Chestnut. 18. Douglas Pine. 19. Laburnum. 20. Mountain Ash. 21. Evergreen Oak. 22. Juniper. 23. Box. 24. Wellingtonia. 25. Willow. 26. Spanish Chestnut. Price, single cases, 3/- ; per doz. £1 14 0 4403T Lantern Slides from photographs of these cases may also be had, and should be ordered as Series B, British Forest Trees, numbers as above. Single slides, plain each, I/- ; per do/. 4404 Fruits and Seeds in cases, ^\ by io|, as above, arranged to show methods of distribution, etc., winged, plumed, hooked ; also of leguminous plants — 7 different cases . . each We can also make up special cases to order. £0 11 6 £030 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 817 BAIRD &TATLOCK (LONDON) LTD. 4408 4408T Botany. By John Hutton Balfour, M.D., F R.S., F.L.S., Emeritus Professor of Botany, Edinburgh. Sheet No. i. — Organs of Tissues, Plants, Root, Stem. 36 illustrations. Sheet No. 2. — Leaves and their Modifications. 36 illustrations. Sheet .No. 3.- — Inflorescence, Whorls of the Flower. 38 illustrations. Sheet No. 4. — Pistil, Ovule, Fruit, Seed, Organs of Flowerless Plants. 44 illustration?. 4409T Elementary Anatomical Botany. By Alexander Johnstone, Lecturer on Botany, Edinburgh School of Medicine. Sheet i. — The Root. 2. — The Stem. Sheet 3. — The Leaf. ,, 4. — The Flower. Sheet 5. — The Flower. 6. — The Seed and Fruit. Size, 34 by 28 inches each. Price, coloured, on cloth and rollers, varnished, 3/6 each ; or 18/- for the complete series. The sheets of this series exhibit in a simple, truthful manner the general structural details of ordinary flowering plants No. i gives a view of the root system and its parts in different sections. No. 2. The stem and bud. No. 3. The leaf and leaf-stalk. Nos. 4 and 5. First the typical flower as a whole and then in parts. No. 6. The fruit, seed, and embryo. The evolution of structures is indicated as occurring in nature, and the whole series can be taken as illustrating the elementary anatomy of a typical flowering plant. Several comparative sections are given through the series. At the foot of each sheet copious explanatory letterpress is given. CROSS STREET • HATTCTK GARDEN, E-C 818 BAIRD &.TATLOCK. (LONDON) LTD. 4410 4410T Botany Sheets for Beginners. By Alexander Johnstone, F.G.S., Lecturer on Botany, Edinburgh School of Medicine. Sheet i. — Roots. ,, 2. — Stems. Sheet 3. — Leaves. „ 4.— Leaves. Sheet 5. — Flowers. 6. — Fruits and Seeds. In another series by the same author, " Illustrations of Elementary Anatomical Botany " (see above), the structural characters of plants as seen under the microscope are exhibited, while in the above set of highly-finished illustrations the external forms as «bservable by the unaided eye, exactly as they appear in nature, are carefully brought out in all necessary detail. Sheet i gives views of the different kinds of common roots. Sheet i shows the shape and different habits of growth of common stems. Sheets 3 and 4 contain numerous interesting examples of leaves. Sheet 5 is made up of typical flowers. Sheet 6 of various common fruits and seeds worthy of being studied by the beginner in Botany. While one sheet is specially devoted to flowers, these structures really appear to a greater or lesser extent in all the sheets, but in no case are the same illustra- : tions given twice. Copious explanatory letterpress is given at the foot of each sheet. Size, 34 by 28 inches each. Price 3/6 each, on cloth, rollers, and varnished, or .on cloth to fold up, with cloth sides ; or 18/- for the complete set of six sheets. 441 11 Trees. Beautifully printed in colours, showing the tree in full foliage, rough cut plank, polished plank, leaf, flower and fruit. With explanatory letterpress at foot. Apple. Ash. Beech. Birch. Cedar. Cork. Elm. Holly. Mahogany. Maple, Great or Plane. Oak. Pear. Scotch Fir. Spanish Chestnut. Walnut. Size, 34 by 28 inches each. Price 3/6 each, on cloth and rollers, varnished ; or £1 16 0 for the selection of a dozen plates. 819 3G BAIRD &IATLOCK (LONDON) LTD. 4412 4412T Plants of Commerce. In this series is given pictures of most of the plants in everyday use, with their various parts. The original paintings for these are produced direct from the plants in the Royal Botanical Gardens, Edinburgh, and may be depended on as being true to nature. Each plate has explanatory letterpress describing the various parts. Coffee, showing plant, leaves, flower, berry, and seed in raw and roasted states. Cocoa or Chocolate Tree, showing tree, leaves, young and full-grown fruit, and section of fruit, and flowers. Also, with similar details : — Barley. Flax. Cocoa-nut Palm. Mustard. Cotton. Oats. Wheat. Orange. Pepper. Potato. Rice. Sugar Cane. Tea. Size, 34 by 28 inches each. Price, 3/6 each, on cloth and rollers, varnished ; or £1 16 0 for the selection of a dozen plates. " The most effective and useful wall charts that we have seen." — The Teacher's Aid. 44131 Collections of Specimens of Wood, showing bark and grain i centimetre thick by 9 by 12 centimetres ; each wood is named. No. i Collection of 20 different woods „ 2 „ „ 30 „ „ 3 „ ., 40 „ 4 .. » 5° „ 5 ,- ;, 60 „ 6 „ „ 70 „ .... „ 7 „ „ So „ „ .. , ,,8 „ 90 „ 9 .. .. I0° ,, 10 ,, „ 120 „ ii „ „ 140 ,, 12 „ ,, IDO „ ,, If packed in special cases so that each specimen is separate, price extra from 9/- to 30/- according to size. Specimens of any other wood obtained to order. £0 9 0 £0 13 0 £0 18 6 £1 5 0 £1 13 0 £2 7 6 £2 15 0 £3 0 0 £3 10 0 £4 2 0 £4 17 6 £6 10 0 CROSS STREET • HATTCXN GARDETST, E-C 820 BARD &TATLOCK (LOMDON) LTD. 4414 4414T " Micro-Telescope," suitable for botanical work, etc., in case It is usual to look upon the telescope and microscope as instruments varying in use and construction. This useful little invention demonstrates how readily the two may be combined. It has strongly appealed to the public as the " Three Optical Instruments in One," and has been an instantaneous success. It has been extensively advertised, and should be in stock by every optician. As a Telescope. It is made of brass, oxydised a semi-dull black finish, which is very neat, and closely resembles vulcanite. Has three draw tubes, cap for object glass and revolving disc for eye-piece, to keep out dust. Closed it is sj ins., and open 15^ ins. long. Magnification over eight diameters. As a Microscope. By merely unscrewing and removing the eye-piece cap and tilting the instrument — the work of a moment — the optical part forming an inner tube, containing all the lenses, except the object glass, can be immediately removed. This inner section is shown in the accompanying illustration. It forms a useful compound microscope, with a magnification ot twelve diameters As a Short Distance Glass. Objects at ten feet distance or beyond may be focussed with draw tubes only. To focus objects from ten down to four feet remove eye-piece cap and pull the inner tube shown in illustration forward. Focus is obtained by increasing or reducing the length with the inner tube, according to the distance of the object. A magnification up to about 20 diameters is thus obtainable. In this one compact little instrument tbe naturalist has the means of viewing the surrounding country with ease, studying insect, plant and cereal life, and by means of the short distance glass he can study the habits of shy birds and insects, or any other animate life which cannot be approached beyond a certain point. £0 10 6 A4414 A4414 The Focostat Lens, for botanical and dissecting work. The lens is very powerful and can be set by means of the universal joints to the exact position to suit the observer's eye. Price with needle £056 TS^SS1 821 BAIRD &.TATLOCK (LONDON) LTD. 4417 4415 4428 6* by 3| 2/6 9 by 4! 3/3 13 by 6| 4/6 each. each £0 1 9 wood ,) £0 3 6 alvanised iron . . • • )> £0 6 0 nj by 10 in. • • » £0 6 6 4415T Botanical Collecting Cases, of japanned tin, lined with cork, square pattern. Sizes Price with strap 441 6T Botanical Trowel in leather case 4417T Botanical Press with strap, frames of wood 4418T Botanical Press with strap, frame of galvanised iron 4419T Johnson's Combined Album-Press, nj by 10 in. 4420T Botanical Drying Paper. Size folded Price per ream . . . . „ „ quire 442 1T Thick White Botanical Mounting Paper. Size . . . . 15 by 10 Price per ream . . 20/- ,, ,, quire .. 1/3 4428T Coddington Lens in metal mounts, for use with lens holder Stand No. 4430. Focus 6, 13, 18, 25 or 37 millimetres . . . . . . . . . . . . each . . . . 16 bv 10 20 by 12 in. !§/- 23/- • • 1/1 1/9 17 J by ii 20 by 12 1 20 by 15 in.' 241- 32/- 40/- 1/6 2/- 2/6 £029 4430 4431 4430T Lens Stand to carry lens, with adjustable joint 4431T Small Dissecting Microscope. With one doublet or magnifying lens With two doublets £0 11 3 £096 £0 12 3 CROSS STREET • HATTOTST GARDETST, E-C 822 BAIRD &TATLOCK (LONDON) LTD. 4492 4492 Opisometer for marking spaces on a growing plant each £0 0 10 4493 4494 4493T Demonstration Auxograph, complete with recording cylinder, revolving once an hour, and is such a size that each millimetre space represents i minute of turning. Complete on stand . . . . . . . . . . . . . . . . . . £5 4494T Leaf Cutter or Punch, for punching out sections of leaves exactly i square centimetre in diameter. Price complete with two perforated cups 4496s Recording Drum, as above, but to revolve once in either 12 or 24 hours 4497s Recording Drum, as above, but to revolve once in either 3! or 7 days 4 0 £2 10 0 4495-4497 4495s Recording Drum, 6 in. drum, simple form, fitted with clockwork to drive at two speeds respectively, one revolution in half or quarter hour. Mounted on heavy sole for use in vertical position . . . . . . . . . . . . £3 10 0 £3 10 0 £3 10 0 BAIRD &TATLOCK (LONDON) LTD, A4498 4498 4498s Recording Lever with electro-magnetic arrangement and writing point, for use with above drums, fitted on stand A4498S Recording Lever, as above, but without stand £2 £1 4499 4502 4499T Auxanometer-Klinostat, with recording drum 4500T Auxomometer-Klinostat, with superior drum, revolving once in seven days . . 45011 Glazed Papers, cut to size and gummed for Nos. 4499 and 4500, per 100, 2/- ; per 1000 4502T Recording Lever, for use with Nos. 4499 and 4500, complete on stand The drum is very light and is of the standard size (6 in. by 6 in.). It does not revolve, but moves through a small arc, and then back to its normal position. The clock, which has a 3O-hour lever movement, is so arranged that it can be set to give an impulse to the drum every 15, 20, 30, or 60 minutes, and can be removed for re-winding without disturbing the record. The tracing being vertical, several levers can be arranged to write on the drum at the same time. A recording drum, revolving once in 7 days, is also made, having superior clockwork movement with jewelled escapement contained in the base. The recording lever is a long light but strong wooden beam, having a writing point at one end, also adjustable knife edges and 2 hooks that can be slid anywhere along the beam. The one is for attaching to the plant and the other for the counter balance weight provided. There is a support for the lever, which can be fixed at any height on the stand. £2 12 £5 0 £0 15 £0 12 0 0 0 6 CROSS STREET • HATTOTST GARDETST, E-C 824 BAIRD &TATLOCK (LONDON) LTD. 4503 4503T Klinostat, with celluloid cover .. .. .. .. .. .. £1 10 The Klinostat has a lever movement the same as the drum, and is made to stand either in a vertical or horizontal position. It is provided with a cork table, 5 in. diameter, which revolves once every 15 minutes. The transparent celluloid cover is 5 in. high. 4505 4506 4504T Ganong's Photo Synthometer for showing the absorption of carbon dioxide by green plants in light with the equidolumetric release of oxygen . . . . £110 4505T Light Screen, large form, as devised by Prof. Ganong . . ..£220 4506T Light Screen, small form .. .. . • •• £176 4508 4508s Respirometer, complete as figured, including bell jar, ground plate, etc. £0 15 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 825 RAIRD &TMTLOCK (LONDON) LTD. 4507 4509 4510 4511 4507r Respirometer, as illustrated, with graduated limb, complete with measuring and reservoir £186 cylinders 45091 Spun Aluminium Pots for holding plants for respiration experiments. Complete with metal band for clamping the rubber stretched over pot. Diameter . . . . . . . . • • 3 4 5 m- Price . . . . . . . . 41- 5/- 6/6 each. 4510s Apparatus for demonstrating the relation between transpiration and absorption . . £05 45111 Ganong's Potometer .. .. .. .. .. .. .. . . £0 14 6 4512 4513 4514 4515 4512s Rubber Tape in rolls, very useful in botanical laboratories for making air-tight joints round stems of plants, etc., width f in. . . . . . . . . per 2 oz. roll 4513s Adjustable Support for bell jar, with one solid base plate and one glass plate with hole in centre to fit on metal sliding support, complete with bell jar 12 in. by 8 in. 4514s Root Manometer for demonstrating root pressure 4515s Apparatus for experiments on root pressure £030 £2 10 0 £050 £060 CROSS STREET • HATTO1ST GARDE1ST, E-C 826 BAIRD &TATLOCK (LONDON) LTD. 4516 4516T Recording Transpirometer, devised by Prof. Blackman and Mr. Paine, Imperial College of Science and Technology. Price of Parts as Figured. A. Solenoid on Stand . . . . . . . . . . £3 15 o B. Balance with Electrodes . . . . . . . . . . £5 lo o C. Clockwork Drum on Stand . . . . . . . . . £3 10 o D. Aspirator Bottle on Stand . . . . . . . . . . £i 10 o E. Electro-magnetic Time Marker on Stand . . . . . . £250 F. Aluminium Outer Pot, 5 in., as Fig. 4509 . . . . . . £066 Price of complete apparatus without battery DESCRIPTION OF APPARATUS. This apparatus is designed to give a continuous record of the transpiration of a potted plant. The apparatus, which is shown in the figure, consists of a balance, a vessel giving a regular flow of water-drops, a tube which is moved to and fro by a pair of solenoids and in its forward position receives the drops of water, a magnetic recording pen moving on a revolving drum, and a battery. The flower pot is placed in an aluminium outer vessel rendered water-tight by a sheet of rubber clamped to its rim. Through the rutber project the stem of the plant and also a short open glass tube fixed firmly in the soil below. Through this tube the soil receives automatically, from time to time, additions of water exactly equal in amount to that lost in transpiration. The balance is provided with a " damper " in the form of a metal disc (seen underneath the pan on the left) moving in a fluid of suitable viscosity (such as lubricating oil or glycerine) ; this prevents movements of the balanced pans in response to slight air currents. Attached to the pans of the balance are ebonite cups containing mercury, and above each pan is a pair of platinum points which can be raised or lowered by means of fine milled heads. The platinum points are in electrical connection with the pair of solenoids (seen on left) and the recording pen (on the right). Through the solenoids passes a metal tube bearing a small funnel at one end. The tube is so arranged that in its forward position the funnel stands just above the mouth of the glass tube projecting from the soil of the pot. A tube connected with a reservoir normally delivers into the funnel a regular stream of drops of water of uniform size, which are conducted away to the vessel placed at the other end of the tube. The pressure of water is kept constant by an open glass tube passing through the stopper of the reservoir, and the rate of flow can also be regulated by a stopcock. As long as the pans of the balance remain nearly level no water can fall into the pot, but as the plant loses weight by transpiration the left-hand pan rises with its mercury cup and so completes an electrical circuit through the pair of platinum points on that side. A current then flows through £16 16 6 BAIRD &TXTLOCK (LONDON) LTD. the left-hand solenoid and the tube passing through it is drawn back, with the result that the water drops can now fall into the soil of the pot through the glass tube provided for the purpose. As the drops continue to fall the left hand pan slowly sinks and the other pan rises and so completes the circuit through the pair of platinum points on the right side. A current then flows through the right-hand solenoid, with the result that the tube is brought back into its forward position and its funnel again receives the falling water drops. The tube remains in this position until the plant has transpired aa amount of water equal to that added, when the circuit is again closed by the rising of the pan. Every time the right-hand pan completes the circuit a portion of the current passes through the pen and so gives a record on the drum of each addition of water to the pot. By altering the adjustment of the pair of platinum points the apparatus can be set to respond to any number of drops, so that even small and slowly tianspiring plants can be made to give records at short intervals. The actual weight of water lost which corresponds to each mark on the record is obtained by catching the appropriate number of drops in a weighed vessel and noting their weight. The drops should be allowed to fall slowly, as owing to the damping arrangement, the response of the pans to slight differences of weight is somewhat sluggish. The amount of water in the soil is kept constant throughout the experiment, and thus a falling off of trans- piration due to a decreasing moisture of the soil is completely obviated. The solenoids are provided with " cut- outs," so that the current only passes momentarily at the time the points first make contact with mercury cups on the pans ; there is thus no sparking from these points, and the position of contact is kept constant. A few drops of oil should be placed on the surface of the mercury of the " cut-outs " ; the volatilization of mercury on sparking is thus prevented. The apparatus requires an E.M.F. of about 3 volts, and so can be worked with two Leclanch6 cells or by storage batteries. (For further details see " Annals of Botany," Vol. XXVII., 1913.) 4517 4522 4523 4517T Demonstration Clinostat, with clockwork drum to revolve once in fifteen minutes £4 11 9 We are always prepared to make any special apparatus to order, and also to make and supply any of the apparatus figured in text books on plant physiology. The following apparatus are taken from Detmer's Moore's " Practical Plant Physiology " : — 4518 Glass Jar for apparatus. Fig. i, page 4 . . . . . . . . ..£016 4519 Glass Vessel with parallel walls. Fig. 7, page 25 .. . . . . . . ..£050 4520 Sach's Bell Jar, lof by 4! in. Fig. 9, page 28 . . . . . . . . ..£0170 4521 Glass Bottle. Fig. 10, page 28 .. . . . . . . . . . . ..£030 4522 Apparatus for the culture of plants in a space devoid of oxygen. Fig. n, page 34 . . £040 4523 Apparatus to prove that green plants can only produce oxygen when CO2 is at their disposal. Fig. 15, page 40 . . . . . . . . . . . . ..£046 CROSS STREET • HATTON GARDE1ST, E-C BAIRD &.TATLOCK (LONDON) LTD. Apparatus as described in Detmer Moore's " Practical Plant Physiology." 4525 4530 4524 Apparatus for the culture of plants in absence of CO.,. Fig. 18, page 53 . . £076 4525 Apparatus for experimenting on assimilation. Fig. 19, page 54 . . £0150 4526 Apparatus for the culture of plants in the absence of all nitrogenous compounds. Fig. 21, page 60 ......' £0 7 6 4527 Washing Cylinder. Fig. 24, page 78 . . . . . . . . . . ..£030 4528 Apparatus for investigating the changes of temperature in freezing potatoes. Fig. 43, page 126 ....'£046 4529 Apparatus for investigating the influence of high temperature on seeds. Fig. 44, page 130 £110 4530 Object Glass for investigating the action of electric currents on plant structures. See illustration. Fig. 45, page 135 . . ..£050 4531 Induction Coil, £ in. spark. Fig. 46, page 136 .... £076 4532 Four 1-litre Bichrome Cells. Fig. 47, page 136 .. . . . . £100 4533 4534 4533s Apparatus for measuring the external work performed by growing seeds. See illus- tration. Fig, 49, page 142 . . . . . . . . . . . . ..£1120 4534 Apparatus for investigating pressure effects due to osmotic processes. See illustration. Fig. 50, page 144 . . . . . . . . . . . . . . . . £036 4535 Apparatus for determining the amount of osmotic pressure. Fig. 51, page 154 .. .. £0 10 6 4536s Unpolarisable Electrodes. Fig. 53, page 158 .. . . ..£110 4537 Apparatus for investigating the diffusion of gases. Fig 55, page 162 . . . . . . £076 4538 Apparatus for investigating the permeability of capillaries to air. Fig. 62, page 174 . . £020 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 829 BAIKD &TATLOCK (LONDON) LTD. Apparatus as described in Detmer Moore's •« Practical Plant Physiology. 4539 4541 4549 4550 4539 Apparatus for determining the permeability of the wood vessels to air. See illustration. Fig. 63, page 177 4540 Poroscope. Fig. 64, page 181 4541 Apparatus for investigating the movement of gases in plants. Fig. 65, page 181 4542 Apparatus for proving the negative pressure .of air in the vessels. Fig. 66, page 183 4543 Apparatus for observing the phenomena of the absorption of water. Fig 72, page 194 . . 4544 Apparatus for the experiments on root pressure. Fig. 73, page 198 4545 Ditto. Fig. 74, page 198 4546 Apparatus for the researches on root pressure. Fig. 75, page 198 4547s Thermostat. Fig. 76, page 202 .. .. '• .'; 4548 Apparatus for illustrating the processes leading to root pressure. Fig, 77, page 205 4549 Apparatus for investigating the influence of pressure on the escape of water from plant structures. Fig. 78, page 207 4550 Apparatus for transpiration experiments. Fig. 79, page 212 £030 £0 1 6 £046 £026 £030 £030 £056 £040 £1 17 0 £050 £020 £086 CROSS STREET • HATTOTST GARDEN, E- C 830 BAIRD &TATLOCK (LONDON) LTD. Apparatus as described in Detmer Moore's " Practical Plant Physiology.' 4560 4551 4552 4551 Apparatus for investigating transpiration. Fig. 80, page 215 4552 Ditto. Fig. 81, page 216 .. 4553 Apparatus for determining the amount of water absorbed and given off by transpiring plants. Fig, 82, page 217 4554s Beranger's Balance, 10 lb. Fig. 83, page 218 .... 4555 Apparatus for investigating transpiration. Fig, 84, page 219 4556s Apparatus for measuring the absorption of water by transpiring plants. Fig. 85, page 221 4557 Apparatus for demonstrating suction due to transpiration. Fig. 86, page 228 4558 Apparatus for demonstrating the readiness with which water moves in the wood. Fig. 87, page 230 4559 Ditto. Fig. 88, page 231 .. 4560s Ozotometer. Fig. 91, page 246 4561 Apparatus for demonstrating the production of CO2 in the respiration of plants. Fig. 93, page 260 £0 10 6 £096 £060 £180 £150 £1 10 0 £036 £046 £050 £1 15 0 £170 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 831 BAIRD &TATLOCK (LONDON) LTD. Apparatus as described in Detmer Moore's " Practical Plant Physiology.' 4562 4567 4562 Apparatus for experiments on plant respiration. Fig. 94, page 261 4563 Apparatus for demonstrating the production of C02 in fermentation. Fig. 95, page 263. . 4564 Kuhne's Fermentation Vessel. Fig. 96, page 263 4565 Respiratory Apparatus. Fig. 97, page 264 4566 Titrating Apparatus. Fig. 98, page 267 4567 Apparatus for investigating the influence of light on respiration. Fig. 100, page 271 4568 Apparatus for experiments on the respiration of roots. Fig. 101, page 273 4569 Apparatus for determining the quantity of oxygen which plant structures can take up in respiration. Fig. 102, page 276 4570 Apparatus for determining the amount of oxygen absorbed and CO2 produced in the respiration of plants. Fig. 103, page 278 4571 Apparatus for investigating fermentation. Fig. 104, page 283 4572 Apparatus to prove that there are organisms which will grow in the complete absence of oxygen. Fig. 105, page 285 4573 Apparatus to investigate fermentation in the absence of free oxygen. Fig. 106, page 286 4574 Apparatus to prove production of heat by plants. Fig. 107, page 288 .. £040 £2 10 0 £050 £0 10 6 £040 £036 CROSS STREET • HATTOTST GARDEN, E- C 832 BAIR.D &TATLOCK (LOTOON) LTD. Apparatus as described in Detmer Moore's " Practical Plant Physiology." Flii 4575 4581 4582 4575s Arc Indicator. Fig. 123, page 377 .. .. .. .. £1 10 4576T Auxanometer. Fig. 124, page 378 . . . . . . . . . . . . £16 0 4577s Horizontal Measuring Microscope. (See Cathe tome ters.) Fig. 125, page 380 .. £5 10 4578 Glass Cylinder. Fig. 126, page 383 . . . . . . . . . . ..£04 4579 Apparatus to investigate growth of roots. Fig. 128, page 387 . . . . . . £02 4580 Apparatus to prove that roots are unable to grow in the absence of free oxygen. Fig. 131, page 395 £0 3 4581 Apparatus to demonstrate geotropic root curvatures. Fig. 140, page 437 . . . . £07 4582 Zinc Case with glass walls to observe the root development. Fig. 141, page 438 .. £0 10 0 0 0 0 0 6 6 6 4583 4583T Clinostat, large pattern, with fan regulator, with solid clockwork movement allowing of one revolution in either 4 to 25 minutes or 36 to 140 seconds. The clinostat can be used in either a horizontal or vertical position . . . . . . . . . . £17 17 0 ,CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 833 BAIRD &TATLOCK (LONDON) LTD. 4584 4584T Registration Apparatus after Phelps, for recording on a drum the growth of plants, consisting of a revolving cylinder 40 centimetres long with clockwork movement. Price •complete as figured with pointer . . . . . . . . ... . . £22 10 0 Botanical Models. The models marked by an asterisk are made of gelatine ; all others are made of papier madid" and wood. MUCOR. 45851 Mucor Mucedo L. Common mould. Plastic imitation, suitably magnified, on board. A. Widely ramified mycelium with sporangium (the latter given in longitudinal section). B. Mycelium with copulating branches. C. Young zygospore with its suspending threads. D. Zygospore germinating, showing exo- and endo-sporium. The first mycelial filament bears a lateral conidiophore. Price £1 13 6 CROSS STREET • HATTOTST GARDETST, E-C 834 BAIRD &TATLOCK (LONDON) LTD. 4585 4586 EUROTIUM. 4586T Eurotium Aspergillus glaucus De Bary. Green mould. Plastic imitation, suitably enlarged, on board. A. Mycelium with conidiophore and conidia. B. Ascogonium in early stage with its pollinodium. C. Ascogonium in advanced stage, involved by the fertilizing thread. D. Young fruit in cross section, showing the wall, the inner filling tissue, and the ascogonial hypha. E. Mature fruit. Price £200 (The imitations of moulds Nos. 4585 and 4586 are made of papier-mache and wood.) MUSCI. 45871 *Brachythecium rutabulum. Capsule of the sporogonium. x 150 . . . . £2186 3. PTERIDOPHYTA. EQUISETACEAE. Equisetum arvense. Common horse-tail. 45881 Fertile tip of a shoot. X 10 . . . . . . . . . . . . ..£0156 4589T *Shield-shaped leaf with sporangia ; two spores with elators, rolled up and stretched, and an archegonium of the female prothallium . . . . . . . . ..£100 4590T *Female prothallium with different stages of developing achegonia. In one of the achegonia the embryo is grown, pushing forth the young root. X too . . .. .. .. £1 12 6 459 11 *Male prothallium with antheridia . . . . . . . . . . ..£0190 B. PHANEROGAMS. 1. GYMNOSPERMAE. CONIFERAE. TAXINEAE. 4592T Taxus baccata. Yew. Male and female cone. X 40 .. .. .. .. £0 15 6 CUPRESSINEAE. Juniper us com munis. Juniper. 4593T Single flower from a male cone ; female flower, with part of the branch and one whorl of leaves. X 90 . . . . . . . . . . . . . . ..£150 835 BAIRD &L TATLOCK (LONDON) LTD. ABIETINEAE. Pinus silvestris. Common pine. 4594T Female cone X 20 and one of its scales X 80 4595T Male cone X 12 and one of its stamens X 50 45961 Pinus silvestris. Germination of pine, x 10. A. *Winged seed. Can be taken to pieces ; the embryo is cut in length and can be\ removed. B and C. Germinating seeds in two different stages of development. D. Young seedling. 45971 *Bordered pit of Pinus sylvestris L., cut across and one half removable. X 3600 2. ANGIOSPERMAE. (A) MONOCOTYLEAE. LILIACEAE. 4598T Lilium Martagon. Turk's Cap. Flower. X 4 . . The pistil can be taken to pieces. 4599T *Scilla bifolia. Cross section of the pistil. X 80. (In frame under glass.) MELANTHIACEAE. 46001 Golchicum uutumnale. Meadow saffron. Flower and bulbotuber. x 2 The tuber is vertically cut. AM ARYLLID ACEAE . Galanthus nivalis. Snow-drop. 4601T Complete flower with stalk and bract, x 4 One of the inner and one of the outer perigonium-leaves can be removed. 4602T Pistil with ovules, magnified. X 16 To show the ovules part of the wall of the pistil must be removed. IRIDACEAE. 4603T Iris germanica. Sword-grass. Flower, x 2 The flower can be removed from the sheath of bracts, so that the epigynic insertion of the perigon can be demonstrated. One of the inner leaves of the perigonium can be lifted out to show the petaloid lobes of the stigma and the stamens covered by the lobes. THYPHACEAE. 4604T Typha la ti folia. Reed club or reed mace. Parts' of the spadix with male and female flowers. Male x 40, female X 100 ARACEAE. 46051 Acorus Calamus. Sweet flag. Solid sector of the spadix with one flower intact and one flower in longitudinal section. X 40 CYPERACEAE. 4606T Carex hirta. Reed-grass, sedge. Male and female flowers. X 18 . . £0 13 0 £0 13 0 £176 £0 18 0 £1 0 £0 10 £1 0 £0 18 £0 13 £0 13 0 £120 £150 £0 13 0 CROSS STREET • HATTQN GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. GRAMINEAE. 4607T A vena sativa. Spikelet of oat. X 30 .. .. .. .. .. .. £176 Can be taken to pieces. 4608T Hordeum distichum. Spike of barley. X3O.. .. .. ..£150 The covering bract of the spikelet in the middle can be removed. The ovary of its flower can be lifted out together with two stamens. One of the lateral spikelets is given in vertical section. 4609T Poa pratensis. Meadow-grass. Spikelet. x 40 . . .. .. .. .. £0 15 6 The first flower of the spikelet is divided into two halves, one of which can be lifted out. 4610 4610* Secale cereale. Rye. Spikelet. x 30 . . . . . . . . . . . . £150 The right half of the spikelet can be removed and taken to pieces. 4611 Section of the spikelet. x 25 .. .. .. .. .. . . £0 13 0 4612T Germination. Longitudinal and cross sections of the lower part of the fruit at the beginning of germination, with the young plant . . . . . . . . . . . . £0156 4613* Fruit of rye (grain). X 60 . . . . . . . . . . . . ..£2140 After removal of the small fork of wire the model divides into two longitudinal halves, which show the aleuron- layer and the endosperm cells stuffed with starch grains. The removable embryo (also longitudinally cut) shows the extremely tender cells of the scutellum, of the calyptra and coleorhiza. The model is accompanied by a trans- parent longitudinal section representing the microscopical structure of the embryo. Two removable parts of the seed, adjacent to the external wrinkled testa of the fruit, represent the extremely hard and the pigment-tissue. 46141 Triticum vulgare. Common wheat. Spikelet. X 30 . . . . . . . . £1 14 0 The central parts can be lifted out and taken apart. 461 51 Section of the spikelet. x 25 . . .. .. .. .. . . £0 13 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 837 BAIRD &TATLOCK (LONDON) LTD. 4616 4616T Zea Mays. Maize. Male and female flowers. X 25 and X 40 (B) DICOTYLEAE. CUPULIFERAE. 4617T Betula alba. Common birch. Male and female partial in florescences. X 70 4618T Alnus glutinosa. Alder. Partial inflorescences of male and female catkins. X 50 . . 4619T Corylus Avellana. Hazel. Partial inflorescences of male and female flowers. Respec- tively X 30 and X 80 . . CHENOPODIACEAE. 4620T Ghenopodium album. Goose-foot. Flower. X 40 Beta vulgaris. Sugar-beet. 462 1T United cluster of flowers. X 40 . . 4622T United cluster of fruits. X 40 . . The upper fruit can be taken to pieces after removal of a small hook. GARYOPHYLLACEAE. 4623T Dianthus Garyophyllus. Carnation. Flower. X 4 Corolla and pistil can be lifted out. 4624T Agrostemtna Githago. Corn-cockle. Flower, x 8. Can be taken apart HIPPOCASTANACEAE. 4625T Aesculus Hippocastanam. Chestnut. Flower. X 15 £1 0 £1 0 £1 0 £1 5 £1 5 • CROSS STRET • HATTOTST GARDE1ST, E-C 838 BAIRD &TATLOCK (LONDON) LTD. 4626 ACERACEAE. 4626T Acer campestre. Maple. Male and female flowers. X 15 .. .. .. £120 0 VITACEAE. 4627T Vitis vinifera. Cultivated grape vine. Hermaphroditic flower of blue Portuguese grape (Oporto grape), with cap-shaped corolla. X 45 . . . . . . . . . . £0180 The model can be taken to pieces and then shows the ovules within the ovary. 4628T The same model not separable. X 45 . . . . . . . . . . . . £0150 46291 Models of Grape Flowers (after Professor Emerich Rathay). X 45. A. Vitis silvestris. Wild dioecious grape, male flower. B. Female flower of the same species. C. Vitis vinifera. Hermaphrodite flower of blue Portuguese grape (Oporto grape). With longitudinal section. The model can be taken to pieces. D. The same flower with cap-shaped removable corolla. E. Female flower of cinnamoni-grape, with section. Whole series, with description £2 14 0 UMBELLIFERAE. 46301 Conium maculatum. Hemlock. Flower and fruit. X 24 . . . . ..£0130 4631T *Cross-section through a half-ripened fruit. (In frame under glass ) . . . . . . £0106 4632T *Foeniculum cappillaceum. Fennel. Cross section through the ripe fruit X 70. (In frame under glass) . . . . . . . . . . . . £0 10 6 LEGUMINOSAE. Pisurn Sativum. Pea. 4633T Flower. x8 .. .. .. .. ... .. .. . . £0 18 0 Vexillum, alae and carina can be removed, then the free stamen and pistil. 4634T *Cross-section of the unicarpellary ovary, x 40. (In frame under glass) . . . . £056 4635* Legumen. X 4 . . . . . . . . . . . . ..£0130 The two valves can be lifted out after removal of a small wire hook, showing the young peas fastened inside, one of which is cut in order to show the embryo with its primary root and plumula. .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 839 BAIRD &.TATLOCK. (LONDON) LTD. 4636T Phaseolus vulgaris. Common bean. Germination. A. Germinating bean B. Young plant showing the two cotyledons and the fir?t pair of green leaves. X 2. 4637T Ononis arvensis. Rest harrow. Flower, x 8 . . Vexillum, alae and carina can be removed. 4638T Trifolium pratense. Clover. Flower. X 25 The model can be taken completely to pieces. SOLANACEAE. 4639T Hyocyamus niger. Henbane. Flower. X 10 The corolla can be lifted out. 4640T *Cross-section of the dimerous pistil. X 57 In frame under glass. 4641T Solanum Tuberosum. Potato flower. X 10 Two stamens and the pistil can be lifted out. The pistil is divided into halves. 4642T Atropa Belladonna. Deadly night -shade Flower. X 5 . . The corolla can be lifted out. The pistil is divided into two halves to show the ovules inside. 4643T Nicotiana Tabacum. Tobacco. Flower. X 6 . . Can be taken completely to pieces. 4644T Solanum Dulcamara. Bittersweet. Flower. X 15 Two stamens and the pistil can be lifted out. The pistil is divided into halves. CROSS STREET • HATTOTSr GARDEIST, E- C 840 BAIRD &X\TLOCK (LONDON) LTD. 4645 4651 CAMPANULACEAE. 4645T Campanula rapunculoides. Bell-flower. Flower, x 7 .. .. .. .. £0 13 0 CUCURBITACEAE. 4646T Gucumis sativus. Common cucumber. Male flower. X 5 . . ..£100 46471 Gucumis sativus. Common cucumber. Female flower. X5 .. .. .. £176 The lower part of the fan-shaped corolla can be removed in both models so that the inner organs can be seen. The model of the female flower moreover shows in a transversal section the structure of the ovary. RUBIACEAE. 4648T Asperula odorata. Wood-ruff. Flower, x 40 . . . . ..£0130 CAPRIFOLI ACEAE . 4649T Lonicera Caprifolium. Honeysuckle. Flower, x 5 . . ..£0130 The corolla can be removed. The style must be unscrewed before. 4650T Sambucus nigra. Elder. Flower, x 25 . . . . . . . . ..£0130 VALERIAN ACEAE. 465 1T Valeriana officinalis. Valerian. Flower. x 15 . . .. .. .. .. £120 Flower with section of the pistil. Models of Six Varieties of Beets. 4652T Red mammoth beet, red Erfurt, red Oberndorf, yellow Leutowitz, yellow olive-beet, yellow giant -beet each model £0 10 6 841 BAIRD &TATLOCK (LONDON) LTD. TYPES OF OVULES. Three Models of Ovules of Angiosperms, representing the bodies in half, after the drawings and directions of Dr. Carl Miller of Berlin. 4653 4654 4653T Atropous (straight) ovule of Rheum officinale Baillon. X 220 4654T Anatropous (inverted) ovule of Oenothera biennis L. X 490 46551 Campylotropous (curved) ovule of Alisma Plantago L. x 390 4656T Price of the whole set (3 models), explanatory text included . . 4655 £176 £176 £176 £380 4657-4659 4657T Model of a Honeycomb, with queen's cell, workers, passage ways, drones, covered and uncovered cells, eggs, larva and chrysalis, on stand, enlarged ten times . . . . £7180 4658T Model of a Working Bee. Ten times enlarged . . . . . . ..£2100 46591 Model of a Queen Bee. Ten times enlarged . . . . . . . . ..£25 CROSS STREET • HATTON GARDErSf, E; 842 tJXJfc BAIRD dcTftTLOCK. (LONDON) LTD. VIII. S ANALYSIS APPARATUS /r^^/r^t ^K^y/rS Haldane's Gas Analysis Apparatus Hempel's Gas Apparatus Orsat's Gas Analysis Apparatus Mine Gas Analysis Apparatus CO2 Recorders Gas Meters, Governors, etc. Photometrical Apparatus Recording Apparatus for Works 860-862 843-846 856-858 860-862 872-875 876-882 884-886 14- CROSS STREET, HMTON GARDEN. BAIRD &. TATLOCK. (LONDON) LTD. The following are the different Sections in or Catalogue. Those marked * are also printd separately. Section No. 1.* Laboratory Fittings 2.* Bacteriological Apparatus 3. Chemical Physiology Apparatus 4.* Microscopes and Microscopical Accessories 5* Balances and Weights 6.* Chemical Apparatus 7.* Botanical Apparatus 8. Gas Analysis Apparatus 9.* Milk Analysis Apparatus 10. Refractometers 11." Oil Analysis Apparatus 12. Water Analysis Apparatus 13. Cement Testing Apparatus 14. Leather Testing Apparatus 15. Paper Testing Apparatus 16. Physico Chemical Apparatus 17.* Pyrometers 18.* Calorimeters 19.* Seed and Soil Analysis Apparatus 20.* Spectroscopes and Polariscopes 21. Volumetric Apparatus 22. Anatomical Models 23. Meteorological Apparatus 24.* Assay Apparatus 25.* Chemicals Pages Nc 14-6 57. I ^ 2 193. ;l 383-i6 817-12 843.16 887 -N 895 -( «2 903 -(!6 927.1-3 934 947 950 952 977- 1007- 6 1023- 1043- 1079- 1088- 1106- 1125- 1187- 12 )5 CROSS STREET • HATTO>J GARDEN, BAIRD &TATLOCK (LONDON) LTD. SECTION 8. Gas Analysis Apparatus. 1 4660 4661 4662 inpel's Gas Burette. The following advantages are claimed for this apparatus : — i i. It admits of the use of all sorts of solid or liquid reagents. I 2. It allows of a complete exhaustion or utilisation of the reagent. 3. It greatly obviates the errors due to the mechanical absorption of gas by the absorbing agents, and tally it can be used for the analysis of mixtures of N, H, and CH4, giving results which are sufficiently accurate f technical purposes. The apparatus consists of — < JO Hempel's Gas Burettes, one plain and the other graduated, on wood soles, connected at the foot by an indiarubber tube. The graduated tube is drawn out at top for the attaching of an indiarubber tube .. .* Without indiarubber tube, per pair £0 10 6 4>1 Hempel's Gas Burettes as above, but graduated tube is furnished with a stopcock at top and a three-way stopcock at bottom . . . . Without indiarubber tube, per pair £015 0 4>2 Hempel's Gas Burettes as above, with patent stopcock. Without indiarubber tube £0 18 6 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. I 843 BAIRD &TATLOCK (LONDON) LTD. 4663 4664 4663 Hempel's Gas Absorption Bulbs, on wooden stand 4664 Hempel's Gas Absorption Bulbs, on iron stand 4665 Hempel's Gas Absorption Bulbs, on wooden stand 4666 Hempel's Gas Absorption Bulbs, on iron stand 4665 £0 6 6 £080 4667 4668 4669 4670 4667 Hempel's Gas Absorption Bulbs for solid absorbing reagents with brown bulb, on wooden stand . £056 4668 Hempel's Gas Absorption Bulbs for solid absorbing reagents with brown bulb, on iron £066 stand 4669 Hempel's Gas Absorption Bulbs for solid absorbing reagents, on wooden stand . . £076 4670 Hempel's Gas Absorption Bulbs for solid absorbing reagents, on iron stand . . . . £086 The Cylindrical Bulbs for solid reagents in Figs. 4667 to 4670 are made in amber glass. 14- • CROSS STREET • HATTON GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. 4671 4672 4671 Hempel's Gas Absorption Bulbs, on wooden stand 4672 Hempel's Gas Absorption Bulbs, on iron stand 4673 Hempel's Explosion Pipette, with platinum electrodes and stopcock 4673 £076 £090 £090 4674 4675 4676 4674 Ettling's Gas Pipette, for solid absorbents, on wooden stand 4675 Hempel's Explosion Pipette, with platinum electrodes and stopcock, for exact analysis, on wooden stand 4676 Hempel's Hydrogen Pipette, on iron stand £066 £096 £096 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. GPiF BAIRD &TATLOCK: (LONDON) LTD. 4677 4678 4677 Hempel's Hydrogen Pipette, on wooden stand . . . . . . . . ..£086 4678 Hempel's Explosion Pipette, with platinum electrodes and stopcock, on wooden stand. . £0 12 0 4679 4679 Hempel's Explosion Pipette, on iron stand 4680 Pettenkoffer's Absorption Tube, for gases (tube only) 4680 £0 14 0 each £019 14 • CROSS STREET • HATTON GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. 4681 4681 Lunge and Zeckendorf's Air Tester, complete in box, without solution 0 DIRECTIONS FOR USE. The carbonic acid present in the sample of air is calculated from the number of times it is found necessary to press the ball before the red colour is discharged. From the table given below it will be seen that the greater the number of pressures required the less carbonic acid is there present in the air. Thus, if only a few pressures are required, the air is very bad ; from 9 to 10 pressures, moderately good ; from 20 to 25, very good. In the open air 40 to 50 pressures would be required. Also, the greater the amount of carbonic acid present, the sharper the discharge of colour. In pure air the change is uncertain and a complete discharge difficult to obtain, but in this instance 3 pressures would only cause a difference in the third decimal place. PREPARATION OF THE TEST SOLUTION. Dissolve exactly 5.300 grammes chemically pure sodium carbonate in about a J-litre of distilled water, then dissolve in it o. i gramme of phenol-phthalin, heating slightly, cool to 18° C., and make up to one litre. This deci- normal soda solution will keep in a closed bottle for a considerable time. For use introduce into 100 cubic centi- metre flask 2 cubic centimetres of this solution, fill up with recently boiled and cooled distilled water to the mark on shoulder, and use 10 cubic centimetres of this for each test. This -^ normal solution must be preserved in a well-stoppered bottle, which, after each opening, is quickly re-stoppered. If the experiments are interrupted for any length of time, it is best to prepare the weak solution afresh. N. B. — This weak solution will not keep more than one day. TABLE. £0 10 6 Number of Pressures of Indiarubber Ball. Parts per 1,000 of Carbonic Acid in the Air. Number of Pressures of Indiarubber Ball. Parts per i.ooo of Carbonic Acid in the Air. 2 3-° 16 0-71 3 2-5 17 0-69 4 2.1 18 0-66 5 1.8 19 0.64 6 i-55 20 0.62 7 1-35 22 0.58 8 1-15 24 0.54 9 I.O 26 °-5i 10 0.9 28 0.49 II 0.87 3° 0.48 12 0.83 35 0.42 13 0.8 40 0.38 14 0.77 48 0.30 15 0.74 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &.TATLOCK (LONDON) LTD. 4682 4683 4684 4682 Oxy -Hydrogen Gas Generator .... . . £0 12 6 4683 Hesse's Apparatus for the bacteriological examination of air, on tripod stand, complete £1 16 0 4684 Carbonic Acid Meter, or Air Tester, Wolpert's, pocket size. The essential principle involved in the use of this convenient and novel apparatus consists in a known volume of air being admitted and shaken up with a measured quantity of sodium carbonate, coloured with phenol-phthalin ; the proportion of carbonic acid present in the air being deduced from the number of cubic centimetres required to decolourise the red solution . . £0 14 0 4685 4685T Palladium Tubes 4686T Palladium Tubes 4686 Price about £150 Price £150 CROSS STREET • HATTOTST GARDEN, E- C BAIRD &TXTLOCK (LONDON) LTD. i 4687 4688 4689 4690 4687 Winkler's Gas Absorption Tube. A. Small, spirals about 3 in. diameter, f in. tube B. Medium ,, 4 in. f in. „ C. Large ,, 6 in. „ £ in. „ 4688 Winkler's Gas Absorption Apparatus 4689T Reiset's Apparatus for the determination of carbon dioxide in atmosphere, with three perforated silver cones, diameter of tube 25 millimetres, height of tube 50 centimetres, capacity of bottle 350 cubic centimetres 4690 De Koninck's Modification of Mitscherlich's absorption apparatus £0 £0 £0 2 I 5 0 I 6 £070 £1 15 £0 4 0 6 ^Z! "3* ' if 4691 Apparatus for the determination of tar in unwashed gases £176 4691 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- R49 BAIRD &TATLOCK (LONDON) LTD. 4693 4694 4693 Apparatus for the estimation of nitrogen tetroxide, complete as figured 4694 Apparatus for the determination of sulphur in illuminating gas £2 15 0 £300 4697 _„,. 4698 4699 4697 Hempel's Gas Analysis Apparatus for determination of sulphur, complete on wooden stand, but without bulb holder . . . . . . . . . . . . ..£1100 (See Hempel's-" Gas Analysis," 1902 Edition, p. 306, English Translation.) 4698 Sulphur Determination, Corleis' flask, 750 cubic centimetres . . . . . . £086 4699 Sarnstrom's Flask, for the analysis of iron . . . . £0 16 0 CROSS STREET • HATTOTST GARDEN, E-C 850 BAIRD &TATLOCK (LONDON) LTD. 4707-4708 4709 4710 4707 Hempel's Apparatus for the determination of carbon in iron. Glass parts only . . £276 4708 Hempel's Apparatus, as above, complete with metal stands . . . . . . £3150 (See Zeitschrift fur Angewandle Chetnie, 1864, i Heft.) 4709 Rothe's Pipette for the separation of iron from small quantities of other metals, based on the fact that ferric chloride in presence of hydrochloric acid and ether gives a compound easily soluble in the latter . . . . . . . . . . . . . . £1 10 0 4710s Pettersen's and Palmquist's Apparatus for the determination of carbon dioxide, improved form . . . . . . . . . . . . . . ..£4150 See German Chemical Society, xx., p. 2129, and Hempel's " Gas Analysis," p. 365, 1902 Edition (English translation). (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 851 BAIRD &.TATLOCKL (LONDON) LTD. —=> fir A4710 A47103 Pettersen's & Palmquist's Apparatus, improved by Professor R. P. Anderson, Cornell University, Ithaca, U.S.A., in portable case . . . . . . . . £5 10 The advantages over the original apparatus are : — A. Greater ease of manipulation. B. More portable. C. Provided with a coil of copper tubing submerged in water to quickly bring the sample to the temperature require DESCRIPTION OF THE APPARATUS. In the sketch, B represents the burette ; P, the pipette ; C, the compensation tube ; M, the manometer ; Z, Z', Z*, t coil of copper tubing ; and L, the level bulb. The upper extremity of the burette connects with the pipette through stopco 1 ; with the manometer through stopcock 2 ; and with the atmosphere, either directly or through the copper coil, throu three-way stopcock Z. The compensation tube connects with the manometer through stopcock 4. This stopcock is made the form shown in the sketch so that the compensation tube may be connected with the atmosphere whenever necessary. Stc cock 5 serves as an inlet for the manometer liquid. The lower extremity of the burette is connected by a piece of rubber tubir which passes under compression screw S to stopcock 6, which in turn connects with level bulb L by means of a suitable leng of patent rubber tubing. The burette, pipette, compensation tube, and copper coil are immersed in water contained in a glass cell, and are support by a board that slides in grooves in the sides of the wooden box which encases the apparatus. The glass cell is of rectangu cross-section and is provided with an opening in the bottom in which is placed a two-hole rubber stopper carrying the low end of the burette and a bent glass tube through which the water may be removed. This cell is held in place by a wooden suppc shaped to fit its base, and provided with an opening through which the neck of the cell extends. The board carrying the buret pipette, etc., can be lifted out of the case when the rubber tube is disconnected from the lower end of the burette and the rubl stopper is loosened from the neck of the glass cell. This allows easy access to all parts of the apparatus for cleaning and repaini Further, the position of this board can be adjusted within certain limits by moving the bolts upon which it rests, up or do1 in slots at the base of the grooves. This makes it a simple matter to adapt new glass parts to an old water jacket and case. The burette has a capacity of about 25 cubic centimetres, and is calibrated in .0025 cubic centimetres, or in parts per io,o< A large saving in height over the old Pettersson-Palmquist Apparatus is effected by giving the lower end of the burette the fo: shown in the figure. The calibrated portion is brought forward near the front face of the cell to afford greater ease and clearrn in reading. The case is provided with a removable front and top to render all parts of the apparatus easily accessible during the manij lation, and with a glass window in the back to give proper illumination when the operator desires to face the window of the roi in which he is working. CROSS STREET • HATTCTNT GARDEN, E-C 852 BAIRD &TATLOCK (LONDON) LTD. 4711 4711s Macfarlane and Caldwell's Gas Analysis Apparatus, complete on mahogany stand, with four mounted absorption pipettes and sloping stand for holding same A modified form of apparatus for the analysis of gases. By Messrs. Walter Macfarlane, F.I.C., and Peter Caldwell. INSTRUCTIONS FOR USE. See Journal of the West of Scotland Iron and Steel Institute, No. 2, Vol. i., 1892. After introducing and measuring the sample of gas, the stopcock is closed and the absorbing bulb E is attached. By gently blowing at F, the capillary G is filled with absorbing liquid. The stopcock is then half turned. We thus have the gas and the liquid all but meeting, as the gas was measured to the end of the stopcock bore, i.e. to the point marked H. The apparatus is then tilted, the stopcock is turned so that the measuring tube (M) and the absorbing bulb (E) are placed in communication, and the gas is, by regulated pressure, forced to bubble through the absorbent. After closing the stopcocks and rocking (if necessary), the stopcock is opened, and the apparatus is so tilted as to facilitate the transfer of the gas back to the measuring tube. When the liquid from E has followed to the point H, the stopcock is closed, the pressure adjusted, and the volume of the remaining gas is read off and noted. The bulb containing the absorbing liquid next in order is then substituted for the first one. Turning the stopcock back to the position shown at B, we blow into the bulb from F, until the liquid in the capillary o is replaced by the new absorbent. Again we have the gas and the absorbent all but meeting. In this manner it is possible to go on through a complex gas analysis without losing even a small bubble of the gas, and yet keep the measuring tube absolutely free from absorbing liquids, a happy state of matters unknown in any other form of works apparatus that we are acquainted with. Another advantage of our arrangement is that there is no danger of an enclosed bubble of air at j (which might be entrapped when the junctions are brought together) being allowed to mix with gases under analysis. The absorbing bulbs are kept charged, and are thus ready for immediate use ; the absorbing liquids are kept free from other liquids, and waste is reduced to a minimum. Some forms of apparatus are very wasteful of chemical absorbents. £5 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 853 BAIRD & WLOCK (LONDON) LTD. ; 4712 4713 4712s Gas Analysis Apparatus, Macfarlane and Caldwell's pattern, modified by Mr. Sodeau, and as used in the Research Department, Royal Arsenal, Woolwich. The apparatus is mounted on polished stand, and has lens sliding on upright for reading graduations on measuring tube ; a 2,1 candle-power electric lamp is also fitted on upright at back of tube. Price, with three special absorption pipettes 4713s Stead's Gas Apparatus, mounted on polished mahogany stand, arranged by Mr. J. E. Stead, F.I.C., Middlesbrough. Price with three laboratory tubes and jars, but without battery, coil, and mercury 4714s Stead's Gas Apparatus, as above, complete with battery and coil, but without mercury Consists of a measuring tube divided into 270 millimetres and platinum electrodes fused into the upper part of tube. The bottom is drawn out to a bore of about \ in. for attaching an indiarubber tube, and the upper end is contracted and joined at a right angle to the laboratory tubes by a three-way capillary tube, a stopcock being placed at each junction. The whole tube is enclosed in an outer glass cylinder. The auxiliary tube is of the same size, and is also enclosed in an outer cylinder. These tubes are connected at bottom by means of indiarubber tubing with a Y piece, which in turn communicates with the mercury reservoir. METHOD OF MANIPULATING THE APPARATUS. Having raised the mercury reservoir above the level of the capillary tubes, the cock at the right end of the apparatus is opened, and the mercury forced to the extremity of the tube. An indiarubber tube at the end of the vessel containing the sample of gas is slipped over this open end. By opening the screw clip and the stopcock, and lowering the reservoir, a sample of gas is rapidly transferred into the measuring tube, and when a sufficient quantity — namely, about 150 millimetres — has passed into it, the clip is screwed down and the stopcock shut off. We now raise the mercury, reservoir until the mercury in the graduated and plain tubes arc at the same level, which point is ascertained by a cathetometer and spirit-level. After carefully noting down the volume of gas enclosed, the mercury reservoir must be raised and the other stopcock opened, and the gas forced into the chamber containing potash. In about two or three minutes the carbonic acid is completely removed, and by lowering the mercury reservoir, and opening again the cock, the gas may be returned into the measuring tube, where its volume is again £7 CROSS STREET • HATTOTST GARDEK, E- C BAIR,D&.TATLOCK(LOM)ON)LTD. jarefully noted. The difference between the first and second volume is the amount of carbonic acid absorbed. Before, however, the gas is drawn back from the gas laboratory vessel, the minute amount of gai which remains in the capillary tube on the right which escapes measurement is expelled. Oxygen gas is now connected to the •nd of this tube, which may be contained in an apparatus similar to that in which the sample of gas was taken, ind a sufficient quantity of it drawn into the measuring tube. In order to thoroughly mix the two gases, they ire forced into the potash chamber and again drawn into the measuring tube, and the exact volume carefully noted. An electric spark is now passed through the mixture, and the contracted volume after cooling is noted. The resulting carbonic acid is absorbed by again transferring the ignited gases into the potash chamber, and after inally obtaining it in the measuring tube, the remaining volume is carefully noted. As the gases remain through- out saturated with aqueous vapour, it is not necessary to make any correction for its tension. The calculations are simple and readily made. Let a = corrected volume of gas taken. Let 6 = corrected volume of gas after absorbing CO,. Let c = contraction after explosion with oxygen. Let d = volume of CO, produced by the explosion. a- b= CO,. . a-(CO, + CO+H) = N. i his form of apparatus is specially adapted for the analysis of blast-furnace gases ; but by introducing an mpruved method of connecting the capillary tubes together it can be very readily adapted to make analyses of any ft of gases. Instead of having only one chamber containing potash, we can increase the number to any A tube containing mercury and a ball of peroxide of manganese saturated with glacial phosphoric acid can I to remove sulphuretted hydrogen ; for absorbing oxygen, a solution of pyrogallate of potash ; to remove url'onic oxide, an acid solution of subchloride of copper ; and heavy hydrocarbon can be absorbed by strong fuming sulphuric acid. By connecting tubes containing these various reagents to the measuring tube, the gas nay be subjected to the action, if required, of all of them. The calibration of the measuring tube or eudiometer is readily effected in the following manner, viz. :— — .'ommencing with the tube full of mercury, pure distilled water is drawn into it until it is full. A small glass lask, contracted at the neck, into which a small piece of sponge is placed, is carefully weighed. The water is now ittle by little forced out of the tube and received into the flask, which is weighed after each addition of water, the height of the mercury in the tube being observed at the same time. It is best to remove about 5 millimetres >f water at a time, making careful weighings and observations after each removal. After having removed all the .vater, a table is constructed which should show the value in corrected volume of the whole scale for each i -Millimetre. 4715 4715 Gas Analysis Apparatus, Orsat's, new form designed by L. M. Dennis. Esq., Cornell University, Ithaca, U.S.A. See Journal of Industrial and Engineering Chemistry (U.S.A.), Vol. iv., No. u Dec., 1912. Descriptive pamphlet on application. £550 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 855 toe1 BAIRD &. TATLOCK (LONDON) LTD 4716 4717 4716 Orsat's Gas Analysis Apparatus, with three absorption bulbs Consisting of a measuring tube holding 100 cubic centimetres graduated to 40 cubic centimetres in fifths, which is connected by means of a capillary tube with branch taps with three absorption bulbs. The gas enters through tube on the left and is measured. It is then passed into the furthest absorption bulb, which contains a solution of caustic potash or soda. This absorbs the carbonic acid, and the gas is now measured and passed into the second absorption bulb, which contains an alkaline pyrogallate solution, where the oxygen is absorbed. After the gas is again measured it is run into the third absorption vessel, when carbonic oxide is removed by an acid cuprous chloride solution. After the final measurement, the residual gas can be discharged into the air through the spare branch of the horizontal tube, and a fresh portion of the flue gases admitted. See Galloway on Fuel. 4717 Gas Analysis Apparatus, Orsat-Lunge, for testing flue gases, with palladium asbestos tube, complete in portable box This apparatus consists of a measuring tube holding 100 cubic centimetres, graduated to 40 cubic centimetres in fifths, which is connected by means of a capillary tube with branch taps with four absorption bulbs. The gas enters through tube on the left and is measured. It is then passed into the furthest absorption bulb, which con- tains a solution of caustic potash or soda. This absorbs the carbonic acid, and the gas is now measured and passed into the second absorption bulb, which contains an alkaline pyrogallate solution, where the oxygen is absorbed. After the gas is again measured it is run into the third absorption vessel, when carbonic oxide is removed by an acid cuprous chloride solution, then, after measuring, the gas is passed into the fourth absorption vessel, containing a 10 per cent, solution of cadmium chloride, which has been rendered slightly acid ; this retains any hydrogen sulphide which may be present. Finally, if the presence of hydrogen is suspected, the gas may be passed through the bent tube containing palladium asbestos, which should be slightly warmed by the spirit lamp to facilitate absorption of hydrogen. After the final measurement, the residual gas can be discharged into the air through the spare branch of the horizontal rube, and a fresh portion of the flue gases admitted. Price of spare parts for Nos. 4716-4717. 4718 Capillary tube with five stopcocks for No. 4717 4719 Capillary tube with four stopcocks for No. 4716 A4719 Burette with water jacket B4719 Absorbing vessel filled with glass tubes C4719 Pressure bottle .... D4719 Indiarubber bellows E4719 Palladium asbestos tube . £2 10 C £3 15 ( CROSS STREET • HATTOTST GARDETST, E- C 856 BAIRD &TATLOCK (LONDON) LTD. 4721 4722 4723 4721 Orsat-Fischer's Gas Analysis Apparatus, small pattern, with two absorption tubes in case .. .. .. .. .. .. .. .. .. ..£276 4722 Orsat-Fischer's Gas Analysis Apparatus, with special stopcock, in portable case .. £3 10 0 4723 Gas Correction Tube, for controlling change of temperature and pressure, with stand . . £090 t^fe^ JL J <~ -'-•'; ^^^^ - «i? °f- * 4724 4724 Elliott's Gas Analysis Apparatus, with explosion pipette (glass parts only) . . (See Mr. A. H. Elliott's article in the Chemical News, igth October, 1883.) £1 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 857 BAIRD &TATLOCK (LONDON) LTD, To Flue for Alight 4725 4726 We direct attention to a new form of the Orsat Apparatus, designed by Simmance & Abady and illustrated above, which possesses the following advantages. Portability. One half the weight and one quarter the bulk of the ordinary type. Durability. The absorption bulbs are compact, strong, and not liable to break, and a breakage can be replaced' at a small cost. Compactness. The concentric absorption pipettes and the general arrangement make the apparatus easy to handle, and it can be shaken bodily so that a complete absorption of the constituents can be obtained. A special form, Fig. 4725, is arranged as a combined CO2 and Flue Draught Tester, the working of which will be clear from the illustration. DESCRIPTION. The apparatus consists of special concentric absorption tubes or pipettes mounted in a semi-circle surrounding the water jacketed burette on a metal stand. The burette is made with an enamel backing, down the centre of which a coloured enamel stripe runs, thus rendering an accurate observation a matter of great ease and simplicity. The form of mounting the capillary tube renders it much less liable to break. The apparatus is provided with a filtering tube for cleaning the gas and a bottle containing water for drawing in the sample and passing it to and from the burette and the absorption pipettes, which latter have rubber bladders fitted to keep the solutions free from contact with air. The apparatus can be lifted and shaken without damage and thus rapid and complete absorption is obtained. When not in use the apparatus is enclosed in a stout metal cylindrical case, dimensions of which are 5j in. diameter, 15 in. high, and the total weight charged with solutions is only 6 Ibs. There is no wood to warp and no part of the instrument is subjected to strain. The apparatus is made in several forms, prices of which are set out below : — 4725T Simmance & Abady's Portable Boiler Tester for ascertaining the percentage of C02 and the draught in flues, complete in portable metal case . . 47261 Do., Do. Orsat Analysis Apparatus, with two absorption bulbs for C02 and O2, complete in case 4727T Do., Do. Orsat Analysis Apparatus, with three absorption bulbs for COa, O2, and CO, complete in case 4728T Do., Do. Orsat Analysis Apparatus, with four absorption bulbs forCO2,O2, and two for CO (to ensure more complete absorption of CO), complete in case . . 4729* Do., Do. Orsat Analysis Apparatus, with four absorption bulbs for CO2,O2, CO, and H2, complete in case £1 15 0 £2 10 0 £2 15 0 £370 £3 12 6 CROSS STREET • HAJTO>T GARDEN, E-C BAIRD &TATLOCKL (LOM)ON) LTD. 4730 4730T Indiarubber Aspirating Pump, tor use with Orsat's Gas Apparatus INSTRUCTIONS. Fill the absorption pipettes with the requisite solutions (according to the gases to be estimated). The water in the levelling bottle should be preferably saturated with the gas to be examined. Draw in a sample of gas so as to fill the burette, then pass it into the pipette containing caustic potash which will absorb carbon dioxide (CO,). The cock on inlet of pipette can then be shut oft and the apparatus shaken. The gas is then passed back into burette and the diminution in volume on remeasuring represents percentage of CO,. If Instrument No. 4725 is used, the remaining examination is for oxygen (O.,), which is similarly ascertained from absorption of the remaining gas by the alkaline pyrogallate solution. If Instrument No. 4726 is used, the remaining examination is for carbon monoxide (CO), which is similarly ascertained from absorption of the remaining gas by the solution of cuprous chloride. (NOTE. — It is better to use Instrument No. 4727 for this and pass the gas into two successive pipettes, one containing fresh solution and the other used solution of cuprous chloride). If Instrument No. 4728 is used, the gas can be examined for HaS by means of a cadmium chloride solution in the fourth absorption pipette. The hydrogen (H,) is ascertained by passing the residual gas over a tube provided which contains palladium asbestos. • Full details on all points are furnished with the apparatus, but the above condensed instructions will show the simplicity of the use of Orsat Apparatus. £036 4731 4731T Taplay's Combustion Gas Analyser, as described below, complete (without mercury) The apparatus illustrated above is a new, accurate and compact instrument for gas analysis by combustion over copper oxide. It has been designed by Mr. J. G. Taplay and was described fully in the Journal of Gas Lighting for April 23rd and April 3oth, 1912. It may be briefly stated that it is used for the accurate deter- mination, by the combustion method, of hydrogen, methene, and nitrogen in gas mixtures ; for determining the carbon density or value of hydro-carbons, and for ascertaining the volume of ethane in coal mine gas. £10 10 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 859 BAIRD &.TATLOCK (LONDON) LTD. 4735 extra 3-way tap. ft. Hip*1 — > 3-way tap attached to apparatus, > to apparatus. 4736 4733 4732s Dr. Haldane's Apparatus for the analysis of small quantities of CO2 in air, portable form in mahogany case . . . . . . . . . . . . ..£330 (For full description and method of using see Blue Book containing Report of Committee on " The Ventilation of Factories and Workshops " (cd. 1302), 1902, price 1/8.) 4733s Mercury Bath, polished mahogany, for use when extracting air from 2 oz. bottles, with 3-way tap A . . . . . . . . . . . . . . . . ..£0116 4735s Bottles for taking samples of air, 2 oz., with indiarubber bands ,.. .. per doz. £0 7 4736s Dr. Haldane's Apparatus, large laboratory pattern for gas analysis, with mercury trough £3 15 CROSS STREET • HATTON GARDEN, E-C BAIRD &TATLOCK. (LONDON) LTD. 4737 4737s Dr. Haldane's Apparatus, similar to No. 4736, but smaller and more portable, for general air analysis . . . . . . . . . . . . . . . . £3 10 0 4738 4738s Dr. Haldane's Apparatus, portable pattern for carbon dioxide, carbon monoxide, and methane in naked light mines, with rod for screwing to case . . . . . . £300 For method of working Apparatus Nos. 4736-4738, see Text Book, " Methods of Air ! Analysis," by J. Scott Haldane, M.D., F.R.S. Price 4/6. .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 861 BAIRD &. TATLOCK (LONDON) LTD. 4739 4741 4742 4743 4744 4745 4739s Gas Sampling Tube, Huntley's. (See Journal of the Society of Chemical Industry, 1910, page 312) 4741 Absorption Tubes for moisture and carbon dioxide 4742 Bunte's Gas Burette, improved, patent stopcock, graduated 15 to o and o to 45 cubic centimetres in fifths 4743 Bunte's Gas Burette, with two stopcocks, the tap at top being a three-way stopcock, graduated 10 to o and 100 cubic centimetres in fifths . . . . . . each 4744 Bunte's Gas Burette, same as above, but with bulb under stopcock, graduated 15 to o and o to 45 cubic centimetres in fifths . . . . . . . . - • each 4745 Gas Burette, by Hempel, unaffected by temperature and alteration of atmospheric pressure ; with patent stopcock, price complete with stands (See Ber. d. Deuisch Chem. Gzsellschaft, XX., No. 13.) 4746 Gas Burette, Franke's, modified form This burette is the results of long practical experience in the analysis of gases, and will be found to be simple, reliable, convenient, and capable of rapid manipulation. It permits of the reagents being used a second time, requires no stand, no pressure reservoir, no three-way stopcock, and in the handling the loss of gas is avoided. Dr. Franke states that an analysis of gas can be completed with it in fifteen minutes. Being small and compact it is thoroughly under control. DESCRIPTION. A measuring cylinder widened at upper end, where it is closed by a stopcock. Graduation, 100 cubic centimetres. Receiver or reservoir for reagents joined to the graduated part by a stopcock with wide bore and closed at lower end by a plug or stopper provided with a stopcock. The wide bore of stopcock between A and B and the plug closing c facilitates the filling and emptying ot burette. The o point of the scale lies in the bore of the stopcock b. The capacity of the measuring part, including stopper bore, is exactly 100 cubic centimetres. Directions for use, see page 863. 4746 £0 10 £0 6 £0 12 £0 10 £0 10 £1 £0 11 CROSS STREET • HATTOTST GARDEN, E-C 862 BAIRD ^T^TLOCK. (LONDON) LTD. DIRECTIONS FOR USE OF FRANKE'S GAS BURETTE No. 4746. To fill the burette allow the gas to stream freely through it for some time. If, however, there is only a small quantity of gas at our disposal, it is necessary to proceed in the following manner : — The burette is first completely filled with water, the plug with stopcock open is then inserted and the stopcock closed. The upper end of graduated part marked d is now connected with the gas source, a, b, and c are opened, and the water allowed to flow out until about the point m is reached, when stopcock a is closed and the burette dipped into a cylinder of water until the level of the water in and outside the burette is the same, in which position stopcock 0 is closed. By this means we have a given quantity of gas enclosed under the usual atmospheric pressure. The plug is now withdrawn, the water run out of the receiver B, and is filled with potash solution, after which the plug with open stopcock replaced and then closed. The receiver B must not contain the smallest air-bubble. Stopcock b is now opened and the potash solution allowed to flow into a, in which it is shaken slightly and then allowed to flow back to B. When all has run back stopcock b is closed, the plug withdrawn, and the solution run off. The reservoir is now washed out with water, and then in the same manner completely filled with water and the plug replaced. The burette is then again inserted into the cylinder of water, stopcock b opened, and at same water level the number of cubic centimetres read off, which give direct the volumes per cent, of carbonic acid which was contained in the analysed gas. If an estimation of oxygen or carbonic oxide gas is required, we manipulate in the same manner, only changing the absorbing reagent. Respecting the carbonic oxide estimation, it is necessary to mention that the water in the graduated part should be drawn off by an aspirator bottle before the absorbing reagent is run in. Then the absorbing liquid (ammoniacal cuprous chloride) is admitted and shaken up with the gas. Afterwards this is drawn off as before and water run in in its place, in order that the remaining trace of ammonia in the residual gas may be absorbed. See Journal fur Prakiische Cliemie, Band 35, February, 1887. 4747 (B) 4748 4747s Aerorthometer, for use at gas testing stations. As prescribed by and made for the Metro- politan Gas Referees (see their notification of June, 1898) . See also original article by Mr. A. Vernon Harcourt, M.A., F.R.S., in the Proceedings of the Royal Society of London, Vol. xxxiv., p. 166 ; Gas World, 4th June, 1898, p. 863 ; Journal of Gas Testing, May, 1898, p. 1258. A. Price of simple aerorthometer, without stopcock B. Price of recording aerorthometer, with stopcock, as figured 4748T Lux's Gas Balance (Description and directions for use supplied with each balance.) £2 10 £3 3 £21 0 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK. (LONDON) LTD. 4758 '. 4749.4757 £ 4760 per ft. One end of tube is closed by a £0 £0 £0 £0 Sulphur Apparatus generally adopted by gas examiners for testing the purity of coal gas. 4749 Bunsen burner, steatite top, metal stand, with air-holes and depression for wide end of trumpet tube . . . . ..£012 4750 Trumpet tube .... . . . . £0 4751 Glass cylinder with hole in bottom . . . . . . . . . . . . . . £0 4752 Glass marbles for cylinder . . . . . . . . . . . . per 100 £0 4753 Beaker . . . . . . . . . . . . . . ..£00 4754 Condenser tube, bent 4755 Wooden table support, adjustable 4756 Indiarubber cap 4757s Indiarubber tube to suit above, i in. bore 4758 Ammonia Cylinder, glass tube, filled with glass beads. stopcock, and the other by a tube ground to fit . . . . . . . . £09 4759 Wooden Stand for same . . . . . . . . . . . . ..£04 4760s Farmer's Gas -Calculator. A graphic method for the correction of gas-volumes, especially for nitrogen-determinations. For the use of teachers, students, and all chemical works in which gas analysis or nitrogen-determinations are required. By R. C. Farmer, D.Sc., Ph.D. Published" by Baird & Tatlock (London) Ltd. . . ..£03 Much time is lost in the re-calculation of gas volumes to normal temperature and pressure ; and even when tables of corrections are used, interpolations are generally necessary. By the use of this graphic method the corrected volume of I cubic centimetre of gas, either wet or dry, can be found with an accuracy of about 2 parts in 10,000 in one single operation, thus eliminating all errors and effecting a great saving of time in all work on gases. A cursor is laid across the diagram joining the points indicating the temperature and pressure at which the gas was measured, and the corrected volume is read off directly. Conversely, the temperature or pressure can be found if the volume is known. The logarithm of the corrected weight of nitrogen can be read off at the same time, thus reducing the calculation of nitrogen percentages to a very simple operation. A series of tables relating to gasometric work and a set of logarithms are attached to the diagram in a con- venient form for reference in conjunction with the calculator. CROSS STREET • HATTOKT GARDE1ST, E-C 864 BAIRD &TATLOCK (LONDON) LTD. ~ BAIRpaTATLOCK. LONDON 4761 4761s Adeney's Gas Analysis Apparatus, made by us to the design of W. E. Adeney, Esq. Latest Pattern, mounted on table with teak top, with raising and lowering arrange- ment for mercury, etc., complete. See Proceedings of Royal Dublin Society, i8th June 1890, and Chemical News, Vol. Ixii., pp. 196-206 . . . . . . . . This ingenious apparatus has also a wide applicability in researches involving the evolution, collection, and measurement of gases. A useful adjunct in every research laboratory. £12 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD ^.TATLOCK. (LONDON) LTD. 4762 Explosion Tube 4762 Sole authorised makers, Baird & Tatlock (London) Ltd. 4762 Section of Measuring i Barometer Tube. 47621 Gas Analysis Apparatus, as used by Dr. W. A. Bone, F.R.S., mounted on strong table with teak top, complete with, induction coil, indiarubber tubing, and battery . . . . £28 15 DESCRIPTION. This apparatus, which is essentially a modification of that introduced many years ago by the late Sir Edward Frankland, has been used by Dr. Bone throughout his researches on the Combustion of Hydrocarbons. It is adapted to all ordinary analytic"1 operations where considerable accuracy is required. The apparatus consists essentially of three parts, namely : — (1) A measuring vessel A made in one piece with barometer B, which is accurately graduated in millimetres. A and B are connected with the large mercury reservoir of the apparatus by means of steel joints of special design, and through the steel tap K. (2) A laboratory vessel D standing in a mahogany trough over mercury, into which the gases are sent for all absorptl purposes. (3) An explosion vessel M of stout glass, fitted with firing wires, and connected with a small mercury reservoir R. The measuring vessel A and barometer B are enclosed in a rectangular water-jacket E E, provided with plate-glass front and sides, and a ground glass back ; a constant flow of water is maintained through the jacket throughout an analysis, thus securing constant temperature conditions and the rapid cooling of gases after an explosion. The large mercury reservoir of the apparatus is fitted into a carrier running between vertical steel guides ; it is raised or lowered, as circumstances require, by means of an arrangement of small pulleys and a ratchet wheel. The top of the barometer B is closed by the glass tap F, and the top of the measuring vessel A by the three-way glass tap G, having two parallel capillary branches, one of which goes to the laboratory vessel, the other is fused on to the capillary tube leading to the explosion vessel. The junction between the measuring vessel and the laboratory vessel is made by means of a device of steel faces and clamp similar to that introduced by Regnault. This device, whilst rendering the junction perfectly tight, allows of the easy removal of the laboratory vessel for cleaning, or other puiposes, as often as circumstances require during an analysis. (Continued on page 867.) CROSS STREET • HATTON GARDEN, E-C 866 BAIRD &TATLOCK (LONDON) LTD. The laboratory vessel D, in which all absorptions are carried out, is closed by a three-way glass tap having two horizontal capillary branches. One of these leads, through the above device of steel faces and clamp, to the measuring vessel, whilst the other is connected with a small water aspirator. The suction of the aspirator enables the laboratory vessel to be filled with mercury at the outset of the analysis, and facilitates the cleaning of the vessel and the changing of the absorption reagent during the analysis. An ordinary filter flask inserted between the aspirator and the laboratory vessel acts as a trap to receive the spent reagent and any mercury which may be drawn over with it. The fresh reagent is introduced into the laboratory vessel by means of a small glass pipette. The inner surface of the measuring vessel A and the barometer B are always kept wet. The moist gases are measured by bringing them to a certain constant volume v (an etched line) in A, and then deducting thin pressure in millimetres of mercury from the reading of the barometer B. The tension of aqueous vapour in the gases is exactly balanced by the tension of the aqueous vapour in the barometer tube, and therefore the difference between the " moist vacuum " reading in B and the reading when the gas is being measured corresponds to the pressure of the dry gas at the particular volume v and tin- temperature of the water in the jacket. The whole apparatus stands on a rectangular table, about 4 ft. 6 in. by 2 ft. 6 in. The general arrangement is shown in the illustration. All readings are made by means of a telescope fixed at a distance of about 3 ft. from the table, the measuring vessel and barometer being illuminated by a movable artificial light at the back of the water-jacket. The chief advantages of the apparatus are : — (1) That it permits of rapid and accurate working. (2) That only small quantities of gas need be used for a given analysis, e.g., the pressure of 5 cubic centimetres of gas is from 50 to 80 millimetres, according to the particular " constant volume " mark employed. (3) That in an " absorption " analysis the quantity of the reagent used is reduced to a minimum. (4) That in an " explosion " analysis the capacity of the apparatus is sufficiently large to allow of the proper degree of dilution of the explosive mixture (e.g., CHt + 2O2) by excess of air or oxygen. This is particularly important in the analysis of hydrocarbon mixtures. The apparatus has been installed in the research laboratories of the Manchester University, at the Listei Institute of Pre- ventive Medicine, London, and at the Battersea Polytechnic, London. The apparatus at the Manchester University has been used for nearly 2,000 different analyses during the past six years. BAIRD HTTATL.O.CIS LUNUDN 4763 4764 4765 Dittmar's Gas Analysis Apparatus. This apparatus, made by us to the order of several of the principal laboratories in England, is pre-eminently fitted for research work and accurate investigation. 4763T Price as figured, complete with iron mercury trough, mahogany cased outside, and two absorption pipettes, Nos. 4764 and 4765 • • 4764T Pipette, modified by Lennox, mounted on mahogany stand 4765T Pipette, modified by Lennox, mounted on mahogany stand . . £11 10 £1 15 £1 12 For description and method of working see " Dittmar's Quantitative Chemical Analysis," 1877, page 209. .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 867 3K «=z» — •> .Sr. BAIRD cVTATLOCK (LONDON) LTD. 4766 4766T Gas Analysis Apparatus, designed by Professors Bone and Wheeler, for technical gas analysis. Price on teak wood stand . . . . . . . . . . . . £10 10 4767T Gas Analysis Apparatus, as above, with lens reading arrangement, on teak wood stand .. £11 10 4768T Extra laboratory vessel for Nos. 4766-4767 . . . . . . . . . . . . £0106 4769T „ absorption vessel, with two stopcocks, for Nos. 4766-4767 . . . . . . £0126 47701 „ measuring tube for Nos. 4766-4767 .. .. .. ..£160 DESCRIPTION OF APPARATUS. This apparatus has been designed by Professor Bone and Mr. Wheeler in response to repeated requests for a convenient and not too costly adaptation of the gas analysis apparatus used throughout their researches on combustion, which shall meet the daily requirements of a commercial or research laboratory. The general character and arrangement of the various parts of the apparatus will be readily understood, with the aid of the accompanying diagram, by all who are familiar with the methods of gas analysis. It comprises, essentially, three parts, viz., (i) a water- jacketed combination of measuring and pressure tubes A and B, communicating, through the glass tap c, with the mercury reservoir D ; (2) an absorption vessel F standing over mercury in a mahogany trough G ; (3) an explosion tube E fitted with firing wires, and connected with a separate mercury reservoir H. All the connections between A, E, and F are of capillary bore throughout, with suitable glass taps wherever necessary. The diagram also shows how connection is made between the measuring tube A and the special " sampling tube " K whenever the latter is employed for the introduction of the sample under examination. The sample may also be introduced into the apparatus, from an ordinary test-tube, under the wide open end of the absorption vessel F, which has been previously rilled with mercury. Before commencing an analysis, the whole of the apparatus including all the connections between A, E, and F, is completely filled with mercury, and, needless to say, all the subsequent operations are conducted over mercury. 14 -CROSS STREET • HATTCHSr GARDETST, E-C- 868 BAIRD &TATLOCK (LONDON) LTD. The various parts of the apparatus are suitably mounted on a strong wooden stand (oak or teak), with four vertical steel rods supporting the shelf upon which the mercury trough G rests, the same rods also carrying another shelf for reagent bottles. Proper provision is made for the raising or lowering (to the ground level if required) of the mercury reservoir D by means of a wooden carrier with suitable pulley and ratchet wheel. The whole apparatus stands in a wooden tray 2 ft. 4 in. by i ft. 6 in. with i in. raised sides. The salient features of the working of the apparatus are as follows : — 1. The principle of measurement employed is that first introduced into gas analysis by Regnault, and subsequently adopted py Sir Edward l'"rankland, viz., the measurement of the pressure of gas (in millimetres of mercury) at constant volume. For :his purpose the gas is brought to a certain " constant volume " mark in the measuring tube A (by suitable manipulation of the nercury reservoir D and the tap c) and its pressure read off on the pressure tube B. There are a series of such " constant volume " marks on A, each coinciding with a 100 millimetres mark on the pressure tube B (i.e., with o, 100, 200, etc., millimetres), so that lie actual pressure of the gas is given by subtracting from the " pressure reading " the numbers o, too, or 200, etc., according :o the particular constant volume mark selected for the analysis. The tubes A and B are made in one piece, which is surrounded >y a water jacket, and their inner surfaces are kept moist with very dilute sulphuric acid (i in 20) as a precaution against the iccidental fouling of the measuring tube with alkalies, and it is obvious that the wetting of A and B with the same liquid eliminates the influence of water vapour upon the gas measurements, the various pressures representing those of the dry gas under examina- tion. The tap closing the upper end of the pressure tube is connected with it by means of stout rubber pressure tubing, a device Iwhich gives a perfectly tight joint with sufficient elasticity to prevent fracture in case the mercury in B is inadvertently allowed to run up the tube with unusual velocity. The tap in question also allows of the vacuum being easily made in B whenever neces- sary. The advantages of this mode of measurement over the more usual method of detenmining the volume under atmospheric ipressure are twofold, viz., (i) it allows of the use of smaller volumes of gas for an analysis, thus from 5 to 10 cubic centimetres of gas can be made to have a pressure of 100 millimetres, according to the particular volume mark selected, and this pressure ban easily be read off to within 0.2 millimetre, without employing a telescope, and (2) the measurements are, of course, independent jf the barometric pressure, and at the same time are unaffected by tension of aqueous vapour. 2. The length of the pressure tube B (about 700 millimetres) amply provides for the proper dilution of the " explosive mixture " in an explosion analysis, even in the case of a rich gas such as coal gas. 3. The arrangements for the various " absorptions " are of the simplest. Instead of using a number of large absorption ivessels each containing a particular reagent, which is used unchanged many times over in successive analyses, all the absorptions jire carried out over mercury in the one absorption vessel r, in each case with a comparatively small volume of the particular nt, which is always used fresh and is at once discarded after use. To facilitate the introduction of the various reagents, and the rinsing out of the absorption vessel with water or dilute sulphuric acid in situ between each successive reagent, the wide (open) end of the vessel is immersed under the mercury in the 'trough G, whilst the top terminates in a capillary three-way tap K. One of the parallel branches of this tap communicates through i stout rubber joint with the measuring vessel A, and the other with a water pump, a large bottle being inserted between the pump md the absorption vessel to serve as a trap for either the mercury or the reagent which is being discarded after use. The insertion )f a tap between the pump and the bottle obviates the necessity of the continuous exhaustion of the latter, a single exhaustion it the outset of an analysis being all that is required. From 2 to 5 cubic centimetres of the particular reagent to be used is introduced into the absorption vessel (previously filled vith mercury), by means of a suitable pipette, from below the surface of the mercury in the trough. Any minute bubble of air accidentally introduced with the reagent can be got rid of by cautiously opening the branch of the tap K leading to the above- mentioned exhausted bottle ; the same device allows of the complete withdrawal of the reagent after use, without taking down ' he absorption vessel, and also of the rinsing out of the latter in situ with water, or dilute sulphuric acid, before the next reagent s used . 4. In point of rapidity of action, combined with accuracy, the apparatus will compare favourably with any other type. An malysis of producer gas can be easily carried out in forty-five minutes, and one of coal gas in about an hour. 5. There are no complicated parts about the apparatus to occasion trouble, and the several parts can be readily detached or cleaning purposes. 6. The apparatus is well adapted for the analysis of almost every kind of combustible gaseous mixture, ordinarily met with n technical practice, including producer gas, water gas, natural gas, oil gas, coal and coke-oven gas, septic-tank gas, blast-furnace ;ases, etc. N.B.— Each apparatus ordered will be personally inspected and approved either by Professor Bone or Mr. Wheeler before being despatched to the purchaser. Any further information as to its vorking will be supplied on application by letter to Professor Bone, Imperial College of Science »nd Technology, South Kensington. For further description of the apparatus see " Journal Soc. Chem. Ind.," 15th January, 1908. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 869 BAIRD &TATLOCK (LONDON) LTD. 4771 4771* BI-Meter CO2 Recorder, O.K. Patent No. 20/1906. Price, complete with all accessories . . . . . . . . . . . . £30 The importance of controlling the percentage of carbon-dioxide emitted by the chimney of a power plant is now so unh recognised that it is not necessary to dwell on this point at length. The engineers of all the important power stations ai works in the country have installed, or are considering the installation of, instruments to enable them and their firemen to exactly what is taking place in their furnaces. To the uninitiated it seems hardly credible that by properly controlli dampers which admit air into a furnace, and by blocking up all cracks in the flues between the furnaces and the chimney, large saving in the coal bill may be effected. Nevertheless it has been proved that in many cases from 10 to 15 per cent, per can be saved by this means. When perfect combustion is secured there is present in the flue gases about 21 percent, o but in practice it is impossible to obtain this percentage since it is always necessary to admit a slight amount of air in in order to avoid smoking. By correctly controlling the dampers, however, the stoker should obtain 15 to 16 per cent, o in the flue gases, according to •tie kind of coal used and other local conditions. In many works (although not in so many i formerly the case), the percentage of CO2 is as low as 5 and in some cases only 3 per cent. If a works in which the perc< is as low as 5 per cent, is able to increase its percentage to 1 5 per cent, they will obtain an over-all increase in fuel effii of about 20 per cent ; that is to say, they will only burn 800 tons of coal where formerly they had to burn 1000 tons. A very little arithmetic will show what a large saving of money this may mean in twelve months. Inefficient combustion is generally due to one of two causes, either an insufficiency of air or an excess of air. In th case smoke is produced, and in the second case the furnace temperature is lower than it should be, and the chimney di is also reduced. In many large towns, owing to the vigilance of the public health officers, the number of chimneys emitting black is being steadily reduced ; and, in his efforts to avoid being fined, the fireman admits a larger volume of air into the fi than is really necessary. This causes a drop in the working efficiency of the boiler due to the cooling of the furnace a: heating up of the excess amount of air. Thus in boiler plants the inefficiency is generally due to a large excess of air s The most efficient results are obtained when the dampers are so controlled that the chimney is always just on the point ( never actually, smoking. It is however unreasonable to expect a stoker to be able to work continuously at this point he has some instrument to guide him. Although air leaking into the flues between the boiler and the chimney does not have the same direct cooling effect furnace as excess of air admitted through the dampers does, yet it is frequently a cause of inefficiency. For, by reduci temperature of the gases in the chimney, it reduces the draught, and therefore not only indirectly reduces the temperat the fire but also prevents the maximum output being obtained from the boiler. In a case with which we have recent!; brought into contact, a careful stopping of all cracks in the flues between the boilers and the chimney raised the percent \ CO, in the chimney by 3j per cent. It is only by having a continuous record that a continuous control can be kept o\ flue and boiler settings, which are so apt to give trouble unexpectedly and to crack in the most un-get-at-able and darkest ; The practice of giving a fireman a bonus on the maintenance of a certain temperature is largely growing in the in < steel trade, and we believe that if a bonus is given to a fireman in a power station on the percentage of CO2 in his chim . shown by a recorder, it will be found one of the best investments that any power station engineer could make. In this connection the following extract from a paper by Professor A. H. Gibson, D.Sc., on " Diagnosis Based on the Ai J of Flue Gases," is of interest : — 14- • CROSS STREET • HATTON GARDEN, E-C BAIRD &TATLOCK (LONDON) LTD. •• The amount of heat which can be rejected up the chimney per Ib. of coal by a careless or inefficient stoker is almost Jible, but even the most careful stoking is handicapped if no means are at hand for determining exactly what is happening 3 furnace, and this is particularly the case when a change-over takes place from one grade of coal to another having a different >osition. A method of stoking which gives very good results in the one case may be very inefficient in the other, and tho satisfactory method of obtaining a clear conception of what is actually occurring in the furnace, and so remedying any ciency, is to obtain frequent analyses of the flue gases." In addition to being a control on the fireman it is a check on the quality of the fuel supplied by the coal factor. There are euower plants In which the saving of fuel directly due to the use of a CO, recorder would not be sufficient to pay for the Instrument within six months. /'/if ('fird obtained with one of our instruments at the Cambridge Electric Supply Co.'s Power Station. Advantages of the Bi-Meter C02 Recorder. Briefly the advantages of this recorder may be summarized as follows : — (1) Since the essential part of the recorder consists simply of two ordinary gas-meters, It Is simple, easily understood, and runs continuously with scarcely any attention beyond changing the charts and renewing the Ume. (2) The Instrument Is enclosed In a metal case and contains no glass parts. It Is as robust as an ordinary gas-meter. (3) No Indlarubber tubing is employed, metallic piping being used throughout. It Is therefore especially suitable for use In hot positions and In the tropics. (4) Since the gas flows uniformly and continuously through the meters, there Is no tendency for any portion of the apparatus to stick. (5) The absorbent material used Is dry lime. (6) The initial cost of the recorder Is low. (7) The cost of running is also very low, being approximately as follows : — (a) About one pennyworth of lime is used monthly. (b) About 29 gallons of water per hour operate the instrument. (c) The cost of renewals or repairs is practically nil. Leaflet dealing with " Instructions for Erecting the Bi-Meter CO, Recorder " describes the details of the instrument more fully. shall be pleased to send a copy to those interested. A complete outfit consists of the actual recorder with the following accessories :— Water tank with ball-cock, soot filter, ake pipe, two tin boxes containing lime, 100 record charts, one water-cock, and one gas-cock with keys, drain pipe funnel, o, for use when first filling the gas-meters : — one bent funnel, a length of one foot of rubber tubing, and a tin can containing tres of oil. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 871 BAIRD &TATLOCK. (LONDON) LTD. 4775 4774-4775 4776 4779 Simmance-Abady Laboratory Meters. 4781 4777 4784 These meters are for the accurate measurement of gas or air in a Variety of sizes and case materials as follows : A. In tinned steel, japanned inside and out, and polished outside. B. In copper, ditto. C. In cast-iron, japanned suitable colour. D. In incorrodible porcelain, enamelled royal blue so as to be absolutely impervious to rust, acid or foul gas, and can be used for the passage of absolutely clean air. The case materials C and D are only used for the smaller meters, but the illustration Fig. 4774 shows the general design of all sizes. Each meter has a foot with levelling screws, plumb bob, cast brass water line sight box with removable lunette glasses (opal at back, clear gtass in front) ; thermometer in brass case, accurately divided dial with polished brass bezel. Each meter has emptying plug, drain from spout, bell metal spindle and bearings carrying block tin drum ; inlet and outlet unions. The capacities are plainly stated in the list on page 873, and illustrations of some of the dials are also shown above. CROSS STREET • HATTON GARDETST, E-C 872 BAIRD &TATLOCK (LONDON) LTD. Capacity. 4774T Laboratory Meter, ft cubic foot per revolution, 18 cubic feet per hour maximum, showing hourly rate by one minute's observation . 4775T 4776* 4777* 4778' Laboratory Meter as No. 4774 but with cumulative index. Fig. dial 4775 Laboratory Meter, fa cubic foot per revolution, 20 cubic teet per hour maximum. Shows from ^^ to 100 cubic feet, also hourly rate. Fig. dial 4776 .. Laboratory Meter, 2.5 litres per revolution, 600 litres per hour maximum. Shows from 10 cubic centimetres to 2.5 cubic metres ; also hourly rate. Fig. dial 4777 Laboratory Meter, £ cubic foot per revolution, 30 to 60 cubic feet per hour maximum (5 It. size). Shows hourly rate 4779T Laboratory Meter as No. 4779 but with index showing from ffo to 250 cubic feet. Fig. dial 4779 4780T Laboratory Meter, J cubic foot per revolution, 60 to 120 cubic feet per hour maximum (10 It. size). Shows hourly rate 478 1T Laboratory Meter as No. 4780 but with index showing from ^^ to 500 cubic feet. Fig. dial 4781 . . 47821 Laboratory Meter, 15 litres per hour, 2 to 4 cubic metres per hour maximum. Shows from 60 cubic centimetres to 15 cubic metres 4783T Laboratory Meter, i cubic foot per revolution, 120 to 250 cubic feet per hour maximum (20 It. size). Shows hourly rate 4784T Laboratory Meter as No. 4783 but with index showing from ^5- to 1000 cubic feet. Fig. dial 4784 4785T Laboratory Meter, 25 litres per revo- lution, 4 to 8 cubic metres per hour maximum. Shows from 100 cubic centimetres to 25 cubic metres A. Tinned Steel. £4 10 0 £660 £6 10 0 £6 10 0 £6 10 0 £9 10 0 £8 10 0 £13 10 0 B. Copper £550 £700 £750 0 £750 £7 10 0 £9 10 0 £11 10 0 £12 10 0 £11 10 0 £12 10 0 £10 10 0 £12 0 0 £15 0 0 C. Cabt-Iron £5 10 0 £770 £800 £800 £900 £10 10 0 £10 10 0 £13 10 0 £15 0 0 D. Porcelain. £6 10 0 £900 £990 £990 In ordering please specify Catalogue No. and case material required (A, B, C, or D). ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 873 BAIRD &TATLOCK (LONDON) LTD. Special Meters. 4796-4799 We also supply two forms of special meters. A. Arranged to automatically shut ofi gas after the passage of a predetermined amount. This is the type used for the Metropolitan Gas Referees' Sulphur and Ammonia Test, but can be applied to any purpose. B. Arranged with special construction for the measurement of compressed gas. This is the type used for measuring gas in experiments with high pressure burners, the gas being delivered at a maximum of about 80 in. water. Simmance-Abady Automatic Stop Meter, Figs. 4796-4799. The stop movement is a very simple one, being exact and shutting off a tap on the outlet of the meter. It can be set to shut off from jV to 10 ft. of gas in tenths, while the stop movement can be also put out of action altogether. A second pointer enables the hourly rate to be adjusted. 4796T In japanned steel case 47971 jn C0per case 4798T In cast-iron case 47991 jn porcelain case £990 £10 0 0 £10 10 0 £12 10 0 4800T High Pressure Meter in cast-iron case arranged with special seal, extra stout drum, and special glands and an arrangement by which pressure cannot be put on the meter unless the outlet is open . . . . . . . . . . . . . . . . £12 10 Note. — All the above Meters are accompanied by a certificate signed by Messrs. Simmance & Abady. -CROSS STREET • HATTCm GARDETST, E-C ' BAIRD ^T^TLOCK (LONDON) LTD. 4801 Laboratory Governors. 4803 4805 For governing the flow of gas and rendering it independent of fluctuations of pressure, the most accurate instrument is the Balance Governor, so called because a bell carrying the valve is balanced in a tank of water or the like. For many purposes a slightly less sensitive form is sufficient and this is furnished by our Double-Dry (leather diaphragm) governor. It is often required, however, to decrease the pressure by a few inches before the gas passes to the measuring apparatus and to the balance governor for final adjustment. For this purpose we make a dry (leather diaphragm) or wet (floating bell) Service Governor. Particulars of all these forms will be found below. 480 1T Balance Governor, very delicate. Tank and bell in incorrodible porcelain, being imper- vious to foul gas and always equal in appearance to new. Long stroke valve. Beam of japanned brass on pillar with anti-friction wheels. Counterbalance consisting of tube for shot and sliding weight on beam. The most sensitive governor manufactured. Complete with syphon cocks, the whole being mounted on small table £4 10 0 4802T Balance Governor, exactly as above, but tank and bell in japanned tinned steel, complete £400 4803T Balance Governor, simple form, but equally sensitive to above, with beam balanced on knife edge, with counterbalanced shot tube, inlet union, and outlet tap and connection. A very sensitive, reliable and cheap instrument 4804T Double-Dry Governor, consisting of two diaphragm governors, the leather being specially selected and prepared. With brass pressure weights, and cup for fine adjustment. In japanned box with inlet and outlet connections 4805T Service Governor, consisting of suspended valve with leather diaphragm and spring adjustment. In cast-iron with cover, 3-light size without base, IS/- ; on base Photometer Benches. The particulars of photometers which we are prepared to supply are divided into three types. A. High Class Laboratory Benches, with steel tubes, following the model used at the National Physical Laboratory. B. Well-made Technical Benches with Wooden Bars of standard section. C. Portable Photometers. In Class A the price in each case includes three carriers, i.e. one for the standard of light, one for the photometer head, and one for the light under test. Otherwise the prices of carriers, standard of lights, photometer heads, lamp rotators, etc., are given separately, but one or two complete equipments are priced as complete photometer sets. £2 10 0 £100 £0 19 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 875 BAIRD &TATLOCK (LONDON) LTD. A. HIGH-CLASS LABORATORY BENCHES. 4806 4806T N.P.L. Photometer Bench Consists of steel bars, 12 ft. long by ij in. diameter, mounted on four cast-iron standards with tie rods and adjustable set screws. Scale of triangular brass divided into millimetres (over 3 metres) and also having a direct reading candle scale by the substitution method. (NOTE. — The scale can be specially divided to suit requirement.) Three aluminium cairiages of finest construction with micrometer adjustments arranged for travelling along the bar, for clamping to the bar, or for coupling together. Two of these carriers are provided with circular divided plates and pointers. The third is provided with eight aluminium screens. 4807* Photometer Bench, as No. 4806 but of simpler construction, with three carriers and without the aluminium screens . £110 0 0 £70 *., 4808 4808T Photometer Bench, as illustration, consisting of steel tubes, 12 ft. by ij in., japanned, engraved with two scales. Provided with winding attachment for actuating carriers for which three are provided, having rack and pinion mechanism and other useful adjust- ments .... .... £43 4809T Photometer Bench, as No. 4808 but with only one scale, i.e. either metric or candle scale, and with the carriers having no rack and pinion adjustment 0 0 £34 0 0 CROSS STREET • HATTCflST GARDEN, E-C BAIRD &.TATLOCK. (LONDON) LTD. 4810 4810T Photometer Bench, as per illustration, being a smaller pattern steel tube bar made on the model of No. 4808 but with steel tubes, 9 ft. by i in., japanned, engraved with two scales, provided with winding attachment for actuating carriers.* three of which are provided, all having vertical adjustment . . . . . . . . . . . . £20 10 0 481 1T Photometer Bench as per 4810, but with one scale only engraved, i.e. either metric or candle scale, without winding attachment . . . . . . . . . . £16 0 0 48121 Wooden Screens for above photometers, either solid or with central aperture . . per pair £200 48131 Engraved Horizontal Quadrant for fitting on carrier of Nos. 4808 to 4811, with plug and pointer for taking electric lamps or gas burner . . . . . . . . . . £0176 B. TECHNICAL BENCHES WITH WOODEN BARS. 4814T Photometer Bar of English Standard section. Made in seasoned pine on mahogany cross foundation, the scale being engraved on inlaid boxwood slip. Each bar made to section shown (full size), French polished and mounted on brass pillars as shown. For direct reading in candle power, lights 60 in. apart . . . . . . . . . . £220 4815T Photometer Bar as No. 4814 but for lights 1.5 metres apart 48161 Photometer Bar as No. 4814 but for lights 100 in. apart 4817T Photometer Bar as No. 4814 but for lights 2 metres apart 4818T Photometer Bar as No. 4814 but for lights 150 in. apart 48191 Photometer Bar as No. 4814 but for lights 3 metres apart .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. PHOTOMETER HEADS, STANDARDS OF LIGHT, LAMP ROTATORS, ETC. 4820 4820T Disc Box only for use with grease spot or star disc . . 482 1T Spare Bunsen or Leeson Star Discs 4824 £3 3 ( per box of 12 £0 12 < 4822T Carrier for above on rollers, arranged for bar or standard section shown above with pointer £1 12 < 4823T Simmance-Abady Patent Flicker Photometer. Head for angle and horizontal testing £10 10 4824T Ditto, for horizontal testing only . . . . . . . . . . . . ..£55 The principle of this is quite a novel one, and replaces the grease spot and similar devices familiar to all experimentalists. By its means light of any colour can be compared with any known standard of light. It is in fact the solution of the " colour difficulty " which has hitherto pressed so hardly on photometrists, especially with modern forms of lighting, &uch as arcs, metallic filaments, incandescent mantles, etc. When the lights are unequal, a flickering effect is present, but when equality is obtained, all that is seen is an apparently motionless disc. With this photometer the " personal error " is avoided, even with the greatest contrast between the lights. 4825T Spare Sighting Wheels for Flicker Photometers Nos. 4823 and 4824 . . . . £07 CROSS STRET • HATTO^T GARDETST, E- C BAIRD &.TATLOCK (LOTsTDON) LTD. 4826 4830 4826T Simmance 1 c. Pentane Standard Lamp .. .. .. .. ..£330 4827T Simmance 2 c. Pentane Standard Lamp . . . . ..£550 4828T Simmance 10 c. Pentane Standard Lamp .. .. .. ..£770 4829T Candle Balance for weighing candles while burning with 40 grain weight . . . . £650 4830T Harcourt's 10 c. Pentane Lamp. This is the official standard for the metropolis, and is the standard adopted by the National Physical Laboratory . . . . . . £880 4831T Standard Sperm Candles, 6 = i Ib. (burning at the rate of J oz. per hour) . . per Ib. £040 4832T Simmance & Abady's Correction Tables for 10 c. Pentane lamp, according to the National Physical Laboratory formulae . . . . . . . . . . ..£220 NOTE. — The Harcourt Pentane Lamp, although the only recognised standard, requires (like all lights derived from combustibles), large corrections for atmospheric conditions. These corrections have been determined and expressed in formulas by C. C. Paterson, of the National Physical Laboratory Messrs. Simmance & Abady have compiled the tables No. 4832 so that all calculation is avoided. The ventilating hygrometer, No. 4833, is all that is necessary if a barometer is available. The importance of these corrections will be obvious when electric lamps are being standardised or tested by the Harcourt Lamp. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 879 BAIRD &TXTLOCK (LONDON) LTD. 4833T Simmance & Abady's Ventilating Hygrometer £3 3 4834 4834T C. G. Paterson's Rotator. This spinner or rotator, which lias been designed by Mr. C. C. Paterson, of the National Physical Laboratory, is of the mercury bath type, and is arranged to revolve lamps suspended vertically at a speed varying from 400 to 30 revolutions per minute. That it is handy may be gathered from the fact that it is made to drop into the central tube of the photometer carriage, and that the total dimensions are 417 millimetres high by 266 millimetres outside (including motor). The construction is such that owing to the mercury bath and amalgamated copper terminals, there is practically no drop in the voltage nor between the rotator and the voltmeter. This is the apparatus used by the National Physical Laboratory. Price £30 0 0 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &TATLOCK (LO^fDON) LTD. 4835 48351 Simmancc-Abady Lamp Spinner, spinning lamps at any angle . . . . . . £20 0 0 48361 Simmance & Abady's Lamp Spinner, spinning lamps horizontally . . . . . . £16 0 0 4837T Lamp Holder to take incandescent glow lamp with shade up to 10 in. diameter for testing at any radial or axial angle . . . . . . . . . . . . ..£600 We illustrate and describe, as examples of photometer equipments, Nos. 4838-4843. It will be obvious that by varying the photometer head or standard of light and lamp holder, different combinations can be obtained. 4838 4838T Simple Photometer. The one illustrated above is shown with pillai for taking electric incandescent lamp, the standard of light being Simmance's i-candle Pentane Standard. The bar is graduated for direct reading in candle-power, the lights being 60 in. or 1500 millimetres apart. The comparisons are made by means of a Bunsen or Leeson disc mounted in polished mahogany box on saddle or carrier, with rollers. The price of the photometer complete, as illustrated is 4839T Photometer, as above, for lights 100 in. apart 4840T Ditto, enclosed for use in light room £12 10 £15 0 £20 0 881 BAIRD &.TATLOCK (LONDON) LTD. 4841 4841T Wooden Bar with Simrnance-Abady " Flicker " Photometer Head (angle and horizontal form), with secondary electric standard lamp, mounted on carrier. Carrier can be attached to winding apparatus provided with bar as illustrated. Simmance I c. Pentane standard furnished for standardising the secondary electric lamp. The arrange- ment is a cheap form of photometer for testing arc lamps or high power gas lamps. Price of apparatus as illustrated, with " Flicker " head, two carriers, and standard of light with 1.5 metre bar 4842T Apparatus as above, but 2 metre bar 4843T Apparatus as above, but 3 metre bar Note.— These benches are simply listed as specimens. It will be obvious that by varying the photometer head or the standard of light different combinations can be obtained. £19 11 £20 12 £21 13 4844 4844T Dibdin's Hand Photometer. This is a simple instrument by which tests can be made of street lamps and the like or of the general illumina- tion in schools, streets, railway platforms, or carriages, and in fact of illuminating effect under any circum- stances. It is small, self contained, and portable, and has a range of from o.ooi to 12 ft. candles. Price, including instructions and certificate signed by Mr. W. J. Dibdin, F.I.C., F.C.S. . . £10 10 ( CROSS STREET • HATTCTK GARDETST, E- C * 882 BAIRD &TATLOCK (LONDON) LTD. 4845 4 & Box Photometer, after Lummer Brodhun, for hand use. The rays of light falling on two dials non -transparent, are reflected on to prism in such a way th^t the image of one of the sides of the dial appears enclosed in the image of the other dial, and thus renders the comparison of the intensity of the light easy. The two discs are reversible 116s Box Photometer, after Lummer Brodhun, as above but larger pattern £550 £7 17 6 4847 4171 Simmance-Abady Patent Combustion Recorder 1 The instrument automatically analyses boiler flue gas, and records the percentage upon a chart. 1 momy in boiler firing is dependent upon the percentage of CO, (carbon dioxide) in the flue gases, and coal which s uld produce 15 per cent, of CO., is frequently so fed with air as to only produce 5 per cent. The loss through p low percentage of CO, is something like a quarter of the fuel bill. These recorders are therefore used to dble the stoker to so operate his firing so as to get a high percentage of COa, and also to enable the proprietor d(i works to see that the coal has not been wasted. The instrument is simple, entirely automatic, and inex- sive, and is made in England. It is also made in combination with a draught recorder, and full particulars 1 be furnished on application. Application should state number and type of boilers, when full details will q:orwarded. This is a practical instrument, and many hundreds are in use all over the world. They undoubtedly e boiler fuel. £25 0 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 883 BAIR-D &. TATLOCK (LONDON) LTD. 4848-4857 Simmance-Abady Patent CO2 Recorders for Works Control. 4858-4859 These comprise special types of automatic recorders for use in kilns, ceramic kilns, beet sugar plants, gas producers, for process gas in chemical works, and other waste gases. They are made with different ranges, and are built to work either with gas under piessure or to draw gas against a draught as high as 30 in. water. In some cases the charts are circulars, as No. 4847, while in others the record is made on continuous tape chart lasting for 60 days. Prices, any of Nos. 4848-4857 . . . . . . . . . . . . . £30 4848T Disc Chart o-io per cent. 4849* „ 0-35 4850T ,, 65-100 „ 4851T „ 0-50 4852T „ 30-50 4853T „ 50-100 „ 4854T „ 80-100 „ 4855T Tape Chart 0-20 48561 „ 0-50 4857T „ o-ioo Note. — In sending enquiries or orders, particulars of maximum and minimum readings and amount of pressure or vacuum should be stated. Simmance & Abady Corrosive Gas Analysers, for paper mills, pyrites burning plants, and chemical works. These recorders work on similar lines to Nos. 4848-4857, but are specially constructed in wood cases with the recording mechanism in separate compartment, while the parts of apparatus coming into contact with the gas to be measured are made of such materials as to resist corrosion. They have been made for SO, and hydrochloric acid gas. Price £35 0 4858T Disc Chart 0-20 per cent. 48591 Tape Chart 0-20 Note. — In sending enquiries or orders, particulars of gas to be analysed, maximum and minimum readings and details as to amount of pressure or vacuum should be stated. CROSS STREET • HATTOTST GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. 4860 4861-4862 Specific Gravity of Gases. We draw attention to two new instruments recently invented by Simmance & Abady for automatically and ontinuously indicating and recording the specific gravity of gases both lighter and heavier than air. The principle employed and patented by Messrs. Simmance & Abady appears from the Patent Office records D be quite original. It consists simply of passing the gas continuously over the crown of a suspended bell and hence up a vertical tube. If air is so passed, the weight of the ascending stream above the crown of the bell ; equal to the weight of the air ( = i) beneath it and the pointer remains at zero. If the gas is lighter than air hen the weight of the ascending stream above the crown of the bell is lighter than the weight of the air beneath : and the bell naturally rises in exact proportion to the gravity while the pointer of course moves over the scale nd stops when equilibrium is reached and thus indicates the specific gravity on the lower scale which is figured •om i (zero) to o. If it is desired to indicate the gravity of a gas heavier than air, then by counter-balancing :ie bell with a weight equal to the weight of the column of air equilibrium is obtained at the other extremity f the scale and if a heavy gas is passed through the instrument the bell will fall and the pointer moves over he scale and so indicate the gravity of gases heavier than air on the upper scale which is figured from I (zero) to 2. The instrument works absolutely automatically and indicates changes of gravity instantaneously and can c easily read to the third place of decimals. It has practically no moving parts and its accuracy has been cmonstrated by series of experiments extending over many months. It will probably occur to those who have worked with gases that the gravity of a given volume of gas will ary with changes in temperature and atmospheric pressure. In the Simmance-Abady Gravitometer, however, : will be seen that the automatic weighing always takes place in comparison with air under similar conditions f temperature, etc., to those of the gas, and that therefore it is the true specific gravity which is always indicated, "ithout the necessity of any correction. 860T Simmance & Abady's Patent Gravitometer, with two scales for automatically and continuously indicating the specific gravity and changes in composition of gases both lighter and heavier than air .. .. .. .. .. .. .. £1210 0 8611 Simmance & Abady's Patent Gravitometer, with pen for automatically and con- tinuously recording on a chart the specific gravity and changes in composition of gases lighter than air, with 100 charts . . . . . . . . • • • • £14 10 0 862T Simmance & Abady's Patent Gravitometer, No. 4761, with pen for automatically and continuously recording on a chart the specific gravity and changes in composition of gases heavier than air, with 100 charts . . . . . . • • • • • • £14 10 0 885 BAIRD &TATLOCK (LOM)ON) LTD. .U PRESSURE AND VACUUM INDICATORS AND RECORDERS. 4864 4865 The illustrations show three forms of Simmance & Abady's Patent Dead Beat Gauges for recording pressure and vacuum of any range and for any purpose. Fig. 4863 shows the instrument with circular chart in cast-iron case but with cover removed, and it will be seen that the gauges require no liquid or mercury, but are connected directly to the source of pressure. Fig. 4864 shows the instrument with circular chart in wooden case so as to be readily portable. Fig 4865 shows the instrument but with a tape chart which lasts for 60 days. The recorders are made in about 1,000 ranges calibrated for inches water, feet head, inches mercury, pounds per square inch, atmospheres, ounces per square inch, millimetres water, centimetres water, millimetres mercury, centimetres mercury and KG per q.c.m. Please state whether vacuum or pressure is required, or combination of both, together with the maximum required to be recorded. 4863T Pressure Recorder with disc chart, in cast-iron case with glazed door and 100 charts . . £610 4864T Pressure Recorder, portable pattern, in wooden case with 100 charts . . . . £70 4865T Pressure Recorder with tape chart for 60 days, with two rolls of charts . . . . £10 0| CROSS STREET • HATTOTST GARDETST, E- C 886 IX. APPARATUS X. 887-894 REFiaCTOMETERS FOR OlL,BUTTER. BEER & SUGAR 895-902 OIL XI. APPARATUS Flash Point Apparatus Viscometers Colorimeters Oil Testers 903-910 911-915 917-922 923-926 14. CROSS STREET. HATTON GAR! CSB? "•^i^^^C*- BAIRD & LATLOCK (LONDON) LTD. The following are the different Sections Catalogue. Those marked * are also separately. Section No. 1.* Laboratory Fittings 2.* Bacteriological Apparatus Chemical Physiology Apparatus Microscopes and Microscopical Accessories Balances and Weights Chemical Apparatus Botanical Apparatus Gas Analysis Apparatus Milk Analysis Apparatus Refractometers Oil Analysis Apparatus Water Analysis Apparatus Cement Testing Apparatus Leather Testing Apparatus Paper Testing Apparatus Physico Chemical Apparatus Pyrometers Calorimeters Seed and Soil Analysis Apparatus Spectroscopes and Polariscopes Volumetric Apparatus Anatomical Models Meteorological Apparatus Assay Apparatus Chemicals 3. 4.* 5.* 6.* 7.* 8. 9.* 10. 11.* 12. 13. 14. 15. 16. 17.* 18.* 19.* 20.* 21. 22. 23. 24.* 25.* n ou printe* Pages Nos. 14- 57. 193.3: 321.3! 383.8 817.8' 843.8; 887. 8( 895.91 903.9: 927.9 934.9 947.9 950.9 952.9 977. 10S 1007.102 1023.102 1043.10 1079. 1C 1088.11 1106.114 1125.11 1187-15 CROSS STREET HATTOM GARDEN, k.. .j i^i*' ^-W_ ^2! BAIRD &TATLOCK. (LOM)ON) LTD. SECTION No. 9. Apparatus for Milk Analysis, and Centrifugal Machines for the Estimation of Butter Fat, &c. Machines. each, 1/3 4871-4874 4875 Leffmann-Beam Centrifugal Machines for estimation of butter fat in milk, etc., as described in Analyst, 1892, vol. xvii., pp. 83, 102, 144. Prices with bottles and pipettes, but without acid — 2 bottle machine 4 6 „ 12 Accessories for Leffmann-Beam Bottles with graduated neck Tubes, plain Pipettes, with mark 3 cubic centimetres . . . . . . each, 4d. ,,9 » ,, 5d. 15 „ . ,. 7d. Automatic pipette, 3 cubic centimetres, with Friedrich's patent stopcock, as figured No. 3184 . . Automatic pipette, 9 cubic centimetres with Friedrich's patent stopcock Hydrochloric acid, pure 1.16 Sulphuric acid, commercial 1.835 sp.gr... Fusel oil, specially purified for milk analysis DIRECTIONS FOR USING MACHINES Nos. 4871-4874. 15 cubic centimetres of milk are put into the bottle, 3 cubic centimetres of a mixture consisting of equal •ts of fusel oil and strong hydrochloric acid are added, mixed, and 9 cubic centimetres of strong sulphuric i of 93 per cent., or specific gravity 1.835, poured in slowly with agitation. The liquid becomes hot and the ein is completely dissolved, a dark reddish-brown solution being formed. The neck is filled to near the zero nt with a hot mixture of sulphuric acid i part, and water 2 parts, and the bottle whirled in the centrifugal chine for from one to two minutes. Milk very poor in fat may require from three to four minutes. The volume at which rises in the neck can be read off directly. If but one test is to be made, it will be necessary, of course, irder to preserve the balance of the arms of the machine, either to make duplicate mixtures, or to fill the other t bottles with diluted sulphuric acid. 71 72 73 74 75 76 77 78 79 80 81 82 83 84 £250 £330 £400 £5 10 0 per doz. £0 14 (I each £0 0 2 per doz. £0 3 6 H £0 4 6 f, £0 6 6 tied No. £0 5 0 , . £0 5 6 per Ib. £0 0 4 M £0 0 2 M £0 3 6 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 887 BAIRD &TATLOCK (LONDON) LTD. -, The advantages of the method are many ; it is extremely rapid, samples can be comfortably analysed in five minutes, with reliable results. It can be recommended to public analysts to sort out milk samples which may be sent them. The trouble of making a fat estimation by this method is very little, if any, more trouble than weighing out of the milk, etc., for the determination of total solids. By the determination of the density, also, the solids not fat can be estimated by the formula o£ Hehner and Ricnmond (The Analyst, xiii., 32), or the milk scale (The Analyst, xiii., 65), with sufficient exactitude to decide whether the milk is undoubtedly genuine or suspicious. A great advantage is obtained by this method, as the necessary further determination can at once be proceeded with while the milk is fresh. For commercial purposes it is also sufficient ; the cost of reagents is small, and the use of ether with its objections is avoided. The error, with care, does not exceed o.i per cent. Machines to be driven at a moderate speed only. 4885 4885 A to I 4885 Milk Testing Centrifugal Apparatus, after Dr. Gerber's system, to work by hand, with accessories, as below. For 4 8 16 tests. Price .. ..£430 £5 13 0 £6 13 0 ACCESSORIES SUPPLIED WITH MILK CENTRIFUGAL MACHINES, No. 4885. Centrifuge for 4 tests. 8 tests. 12 tests. 16 tests. Price. A. Tubes No . 4887 with stoppers 4 8 12 16 1/9 each. B. Milk pipettes . . i 2 2 2 7d. „ C. Acid pipettes . . i 2 2 2 5d. „ D. Alcohol pipettes i 2 2 2 4d „ E. Stand for tubes i I I I 3/- „ F. Spirit lamps i I I I I/- „ G. Brushes 2 4 4 4 Id. „ H. Thermometer i • i i 2/- „ I. Water bath I j i i 4886 <886 Gerber's Tubes for centrifuge, with enamelled back, grad. to 8% 4887 Gerber's Tubes as above but with plain back, grad. to 8% 4888 Gerber's Tubes as No. 4886 but with flat tube, grad. to 8% each, 1/9 ; per doz. , 1/6; „ „ ,. 21- ; „ „ £100 £0 17 0 £130 CROSS STREET • HATTOTST GARDEN, E-C 888 BAIRD ^TATLOCK (LONDON) LTD. 4889 4890 4889 Gerber's Tubes for estimating the percentage of butter fat . . 4890 Gerber's Tubes for estimating the amount of water in butter 4891s Shaking Apparatus to carry 24 Gcrber's tubes 4892 4892 Gottlieb's Tubes 4893 4894 4893 Indiarubber Corks, double cone, for Nos. 4885-4888 A4893 Indiarubber Corks, single, for Nos. 4886-4888 . . 4894 Wooden Stands— To hold . . 10 Price .. .. 3/- 4895 Shaking Case for 8 Gerber's tubes 4896 Pair of Tared Tin Dishes for we ghing cream, 2 by ijj in. 4891 each £029 £023 £1 15 0 per pair £036 4895 each, 3d.; per doz. £029 2d.; £0 1 10 24 tubes. 5/- each. per pa.r £076 £010 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 889 BAIRD &TATLOCK. (LONDON) LTD. •'. 4897 4906 4897s Milk Testing Centrifugal Apparatus, Lister & Babcock, improved form for hand power. 4 6 8 10 16 20 bottle tester. £350 £3 10 0 £3 15 0 £400 £500 £5 15 0 each. Above prices include bottles, pipette, acid measure, acidimeter, and butter fat chart. Extra Glass Fittings for above. 4898s Ordinary Babcock Test Bottle .. .. .. .. each, 1/7; per doz. 4899s Lister's Ai Double Neck Bottle .. .. ,.2/8; 4900s Cream Bottles .. .. .. .. .. ,,1/7; 4901s Cream Bottles, new pattern .. .. .. ,,1/7; 4902s Separated Milk Bottles .. .. .. .. ,,1/7; 4903s Sulphuric Acid Measuring Flasks .. .. .. .. ,,1/7; 4904s Milk Pipette .. .. ,,1/7; 4905s Milk Pipette (half size) .. .. .. „ 1/1 ; 4906 Apparatus, after Prof. Soxhlet and Henkel, for the estimation of acidity in milk DIRECTIONS. To 100 c.c. of milk is added 4 c.c. of a 2 per cent, solution of phenol phthalein in alcohol, and as much N/4 caustic soda added from the special burette (which automatically fills itself to the zero point) as will impart a marked red colour to the milk. The number of c.c. added gives the degree of acidity. Milk which has become curdled through boiling shows from 5.5. to 6.5°, and milk which has curdled at the ordinary temperature from 15 to 16° of acidity. The estimation of acidity in milk, cream, etc., is of importance when the milk is accepted at the creameries ; also in testing buttermilk for its applicability in the preparation of cheese rennet, for checking the acidity in the preparation of butter from acidified cream, in testing milk for making Parmesan cheese, etc. Solutions — Phenol phthalein too c.c., bottle, 1/9. Caustic soda N/4 per litre bottle, 3/8. 4907 Basins, Royal Berlin Porcelain, shallow af in. diameter, capacity 45 c.c., glazed inside and outside for milk analysis, as recommended by Professor Stokes. See also Nos. 1940-1941 . . . . . . . . . . . . each, 1/2 ; per doz. £0 12 6 £0 18 o £1 10 0 £0 18 0 £0 18 0 £0 18 0 £0 18 0 £0 18 0 £0 12 0 £1 12 0 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &TATLOCK. (LONDON) LTD. 4908 4908s Richmond's Slide Scale, for estimation of fat in milk, with extra scale for correction of specific gravity with temperature . . . . . . . . . . each METHOD OF USING RICHMOND'S MILK SCALE. To obtain the percentage of fat, place the line indicating the specific gravity against the line showing the total solids, and read off the percentage of fat to which the arrow on the right of the scale is pointing. The lactometer readings on the scale are utilised thus : — Should the temperature at which these readings are taken be either above or below 60° F., the corrected reading may be obtained by placing the line showing the reading obtained against 60° F. on the temperature scale, and then noting the lactometer reading opposite the temperature at which the milk was tested. For example : — If the lactometer reading be 32.1 and the temperature 70° F., the reading corrected to 60° F. will be 33.5° £050 4909 4910 4912 4913 4914 4915 4916 4909 4914 4915 Soxhlet's Apparatus, complete as figured, with flask, condenser and Soxhlet's extraction apparatus, basin on stand with burner, stand and clamp for holding condenser, etc. Separate parts. without IR tubing, each Flask 125 c.c. . . . . each. 3d- •' Per doz- Ball Condenser, Soxhlet's, nickel-plated each Soxhlet's Apparatus, 100 grammes . . Dairy Thermometers in wood frame, with handle, marks, indicating freezing, churning, cheese, and scalding . . 8 in. long, each, 8d. ; per doz. 12 in. , ,, lOd. ; „ Automatic Acid Measure, absolutely accurate. Prevents the unpleasantness of pipetting acid, and renders mistakes impossible. For measuring sulphuric acid for Dr. Gerber's butyrometer, capacity 10 cubic centimetres Automatic Acid Measure as above, with metal stand and ring, complete £0 £0 £0 £0 £0 £0 £0 £0 16 2 5 3 7 9 15 17 6 9 6 0 0 0 0 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 891 BAIRD ^TATLOCK (LONDON) LTD. 4917 4917 Cassall's Porcelain Slippers, for weigh;ng out fat . . each £020 ccn 5 1 :" 4918 4919 4920 4921 A4921 4922 4923 4918 Stokes' Tubes, for estimation of fat in milk, 50 cubic centimetres (see Analyst, p. 228) 4919 Stokes' Tubes, for est'mation of fat in milk, 50 cubic centimetres 4920 Rennet Glass, graduated 2 oz. in 200 parts 4921 Graduated Cream Tubes, o to 30 % A4921 Graduated Cream Tubes, o to 23%, on sole 4922 Marchand's Milk Tester 4923 Chevalier's Cremometers, with stopcock 4924 Chevalier's Cremometers as Fig. 4923, without stopcock . . 4925 Lactometer, paper scale, 0-40, in case, with immersion cylinder 4926 Lactometer, 0-40, ivory scale, in leather case, best English make 4927 Lactometer, gilt metal 4928 Pipette, to deliver 5 cubic centimetres milk of 1.032 spec'fic gravity, 60° F. 4929 Tubes, graduated, on feet, for the estimation of curd water in butter each 1/6 ; 4930 Lactometer, Veith's pattern, 25 — 35 4931 Lactometer, Soxhlet's pattern, about 13 in. long, without thermometer 4932 Lactometer, „ „ „ with each, 1/9 ; per doz. £1 0 0 each, 6d. ; per doz. £9 5 6 each, 9d. ; per doz. £0 8 6 . . £9 2 0 £0 3 6 . . £0 1 6 each, 9d. ; per doz. £9 8 0 £0 3 0 . . £0 10 6 3° F. £0 0 8 each 1/6 ; per doz. £0 15 0 . . £0 2 0 r £0 2 6 £0 5 6 • CROSS STREET • HATTON GARDETST, E-C RQ? BAIR-D &TATLOCK (LONDON) LTD. j^ggujg; 4937 4933 4935 4933 Dairy Acidimeter, as recommended by Mr. J, M'Creath, F.C.S., for determining the acidity in cheese and butter making. Descriptive pamphlet on application. Price, complete, consisting of burette and fittings, stand, two pipettes, one drop bottle for indicator, porcelain basin, stirring rods, with half-Winchester standard caustic soda solution, and 150 cubic centimetre phenol phthalein, including packing case 4934T Extra half- Winchester standard caustic soda solution, including bottle each, 3/8 ; per doz. 4935 Reichert-Wollny Apparatus, for the determination of volatile fatty acids in margarine and butter (for description see Analyst, December, 1900, pp. 309-313). Price of standard apparatus, as figured, including burner, and tripod 4936 Reflux Condenser, I.R. cork and T tube, as used for first stage of above method (see Analyst, p. 312) 4937 Polenske's Modificat:on of the Reichert-Meissl Method for the detection of cocoa-nut oil in butter. Price, complete as figured, made to Standard measurements The method is based upon the determination of the volatile insoluble fatty acids which distil over in the ordinary Reichert-Meissl process. To obtain concordant results the distillation must be carried out under certain conditions and in an apparatus of the dimensions shown in Analyst, vol. xxix., p. 155, and the use of alcohol for saponification must be avoided. 4938r The Laboratory Book of Dairy Analysis. By H. Droop Richmond, F.I.C., Analyst to the Aylesbury Dairy Co. Illustrated with photographs by the Author and containing a list of the necessary apparatus and chemicals required for the analysis o; milk, butter, etc. and Edition £0 14 £2 2 0 0 £0 12 0 £066 £0 12 0 £026 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 89.3 BAIRD &TATLOCK (LONDON) LTD. n IOCS -i 4939 4940 A4943 4942 4943 4941 APPARATUS DESIGNED BY DR. HOUSTON FOR THE BACTERIOLOGICAL EXAMINATION OF MILK. 4939 Separator, with stopcock, marked at 1,000 cubic centimetres, and narrow tube above stopcock graduated to .4 cubic centimetres in forty divisions . . . . each £0 4940T Tube, for whirling in the centrifugal machine, marked at 10 cubic centimetres, and graduated to .2 cubic centimetres in twenty divisions . . . . each, 1 /6 ; per doz. £0 (See Nos. 876-904 for Centrifugal Machines.) 4941 Pipettes, Capillary, .01 cubic centimetres, with indiarubber tubing and mouthpiece each, 2/- ; per doz £1 4942 Pipettes, plain . . . . . . . . „ 2d. ; ,, £0 4943 Pipettes, with teat .. .. .. .. , 4d. ; £0 A4943 Brass Wire, bent at top . . . . . . . . Id. ; £0 3 0 1 9 3 9 0 11 BAIRD &TXTLOCK (LONDON) LTD. SECTION No. 10. Refractometers for Oil, Butter, Beer, and Sugar Analysis, Fig. I (i full size) 4944.4947 Fig. 2 (Section) 49441 Dipping Refractometer, Zeiss', in case, with attachable beaker and with a table for the conversion of the scale readings into refractive indices The lower end of the refractometer is immersed in the middlemost of the five beakers of the front row. The rectangular mirror fitted under the trough reflects the light of the bright sky through a glass plate upwards into the beaker and through the fluid into the refractometer. The latter hangs by its hook H upon the wire frame T. Observations are made from above by means of the ocular Oc. The border line of total reflection is achromatised by turning the milled ring R. The micrometer screw z supplies one-tenth scale divisions. Accessories (Set A). 4945T Auxiliary Prism 49461 Heating Trough A 4947T Two Thermometers (see Nos. 4952-4953) 4948r Heating Spiral, Fig. 4972 . . 4949T Cistern A of the Water-pressure Regulator, Fig. 4973 £12 10 0 £0 12 0 £1 10 0 £136 £3 1 0 £070 £19 3 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 895 BAIRD &TATLOCKL (LONDON) LTD. 4950T 4951T 4952T 4953T 4954T 4955T 4956T 4957T 4958T 4959' 4960' 496 1T 4962T 4963T 4964T 4965T 4966T HEATING APPLIANCES FOR REFRAGTOMETER No. 4944. I. Heating Trough with current of water at a constant temperature. Heating Trough A, with 24 glass beakers of 20 cubic centimetres capacity Heating Trough B Thermometer, 15-25° C., divided in j1^0, with fixed metal case and certificate Thermometer, 15-25° C., divided in 1°, with a red line at 17.5° C. Heating Spiral Cistern A of the Water-pressure Regulator II. Tempering Bath (available without a continuous flow of water)— Enamelled Pan, with felt jacket and overflow joint, I metre rubber tubing, and stopcock Filler to above Carrier for the Refractometer and Mirror Umbrella Frame for 12 beakers, also 24 glass beakers 20 cubic centimetres capacity Thermometers, Nos. 4952-4953 SET B. Refractometer with Auxiliary Prism See Figs. 4944-4947 Enamelled Pan Filler .... Carrier Umbrella Frame Thermometers, Nos. 4952-4953 4967 4967 Refractometer, Thornoe's, for analysing beer, with Hallwach's differential prism, complete, including illuminating lens on stand, magnifying glass for taking readings, and calculation tables, in case A. One gas sodium burner, with one platinum ring B. Two specific gravity hydrometers (one from i.oioo to 1.0330, the other from 1.0320 to 1.0560) C. One hydrometer jar D. One thermometer, from 10-32° C., divided in tenths of degrees £1 10 0 £0 16 0 £100 £036 £3 1 0 £070 £0 15 6 £050 £143 £166 £136 £13 2 C £0 15 6 £050 £1 4 3 £166 £1 3 6 £17 16 9 £14 0 £0 17 £2 10 £0 4 £0 7 £17 19 CROSS STREET • HATTON GARDE1ST, E-C 896 BAIRD &TATLOCK (LONDON) LTD. 4972 4973 4968r Butter Refractometer, Zeiss', for the refractometric examination of butter and lard. Price in case, complete, without thermometers 49691 Ordinary thermometer for above . . . . . . . . . . . . extra 4970T Wollny's thermometer for direct reading 4971T Baier's 4972T Heating spiral, with two glass tubes for rubber connections . . . . . . ,. 49731 Water-pressure regulator . . . . . . . . . . . . „ 49741 Sodium burner, with one platinum ring . . . . . . . . . . „ £10 £0 £0 £0 £3 1 £0 12 0 0 5 0 7 6 9 6 0 0 £0 15 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK. (LONDON) LTD, w 4980 4980T Refractometer after Pulfrich, by Zeiss, for ordinary work in physical and chemical laboratories, with full directions and all necessary tables, with one GeisslerH tube No. i /. A. Spare Geissler tube . . . . . . . . B. Prisms I., II., and IV. .. C. Heating apparatus .. .. .. .. .. .. . . D. Ordinary thermometer, 0-75° C. . . . . . . . . . . E. Thermometer, 0-50° C. in 3^° F. Thermometer, 50-100° C. in T\j° G. Heating-spiral (Fig. 4972) . . H. Water-pressure regulator (Fig. 4973) I. Two bottles, with cap and rod . . . : J. One bottle monobromnaphthaline . . K. One curvature glass gauge L. One sodium burner, with one platinum ring Price of complete instrument . . . . . . 4981T Extra prisms (B) for Refractometer No. 4980. No. .. .. .. .. III. Price £3 10 0 £23 15 (I £0 8 ( I £819 lj £2 15 f the fork provided for that purpose, which ensures steadiness of movement, and prevents the walls of the cup from becoming oily above the proper level. The thermometer having been inserted in the socket in the cover, the gas burner is lighted beneath the wire gauze screen, and the rate of heating so adjusted that the temperature af the oil under examination rises 10° F. in each minute. The gas test-jet is then lighted, and is regulated by means :>f the screw valve until the flame is of the size of a small pea. During the heating of the oil the stirrer is used from time to time. At each rise of one degree of the thermometer, the test flame is applied by rotating the spindle until the flashing point is reached, the use of the stirrer being intermitted while this is done. If the flashing point 3f the oil is known approximately, the rate of heating may at first be accelerated by using a larger flame and by removing the wire gauze, but the rate must be adjusted to 10° F. per minute at least 20 degrees below the flashing point. As traces of the more volatile hydrocarbons considerably reduce the flashing point, it is essential that the apparatus during use should be kept free from such. It is also necessary to keep the oil cup perfectly dry, as traces of moisture interfere with the production of the flash. Care must therefore be taken that the oil is free from water before testing. If the heating agent is gas the test flame is also gas, but where gas is not available the test flame is fed with rape or mineral oil. The oil flame is regulated by adjusting the wick, the gas-jet by a regulating screw. Further particulars of this apparatus are given in the second part, 1889, of the reports of the Konigl. tec/in. Versuchanstalten, Berlin, pp. 64-74. £5 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 909 BAIRD &L TXTLOCK (LONDON) LTD. Sole authorised makjrs, Baird & Tatlock (London) Ltd. 5005-5006 Section of cup and iron jacket. 5005-5006 5005s Flash Point Apparatus, Gray's, for heavy mineral oils, improved form, suitable for testing oils to 700° F., complete, with thermometer graduated to 550° F., in mahogany case See Soc. of Chem. Ind. Journal, April, 1891, p. 348. 5006s Flash Point Apparatus, Gray's, complete, with thermometer graduated to 700° F. (nitrogen filled) . . A50065 Extra thermometers for above, ioo°-550° F. . . . . . . . . each s5006s ,, „ „ nitrogen filled, 300-700° F. . . . . „ DESCRIPTION. This apparatus consists of a brass oil-cup, a, of the same dimensions as the oil container used in Government standard petroleum testers (Abel's). On this cup, which is set on a suitable stand, is placed a tight-fitting cap or lid. Through the lid a steel shaft passes, carrying on the top a small bevelled wheel, h, the bevel of which is milled, and on the lower part two sets of stirrers, one of which is below the surface of the oil, and the other in the vapour space above. A horizontal shaft carried on two standards terminates at one end in a bevelled wheel, g, which gears with the other bevelled wheel, h, and at the other end in a disc, c, the outer rim of which is made of bone or other suitable non-conductor of heat, and on this disc is fixed a handle, b, for rotating the shaft. This horizontal shaft carries a collar, e, from which there projects two small pins at diametrically opposite points. By sliding the shaft slightly to the right the bevelled wheels are drawn out of gear, and the pins protecting from the collar put in position for actuating the testing arrangement. On the lid proper there are three orifices, one im- mediately in front of the test-light d, and the other two at either side of it. Above the lid is the sliding cover, s, in which there are two orifices corresponding to those on the fixed lid. When the bevelled wheels are in gear the sliding cover is held in its normal position by the spring at p, and the orifices in the fixed lid are covered. When the sliding cover is moved by bringing the pin e in contact with the pin at p, and turning the disc c about a quarter of a turn round, the orifices in it coincide with those on the fixed lid, and at the same time the test- light d is depressed and brought into position for producing the flash when the proper temperature has been reached. In places where gas is not available the apparatus can be supplied fitted with oil test-jet instead of gas. THE FOLLOWING DIRECTIONS MAY BE FOUND USEFUL. Fill the oil-cup a up to. the mark inside with the oil to be tested, replace the cap, and insert the thermometer in the tube provided for it. Apply a light to the heating lamp, the heat from which may be applied direct. Light the test-jet also, and adjust flame to about J of an inch in length. During the heating of the oil the stirrers should be moved at short intervals by turning the handle b several times. The more rapidly the oil is heated th« oftener the stirrers should be rotated. When nearing the point at which the oil is expected to flash, it is advisable to reduce the rate of heating in order that the observations may be more readily and accurately made. If necessary, a rough test may be performed first, to give some indication of the temperature at which the oil is likely to flash. Observa- tions may be taken every degree or half-degree, a few turns of the stirrer being given between each test. The rate of heating is immaterial, provided it is not too rapid to allow of readings being taken. A convenient time is ten to twentv minutes. £400 £4 £0 £0 5 6 11 CROSS STREET • HATTON GARDETST, EC BAIRD &TATLOCK: (LONDON) LTD. 'Vf*i*' r •> i Registered No. 592,988 Section of Viscometer. 5007 5007 5007T Sir Boverton Redwood's Standard Viscometer, Admiralty pattern for testing oil fuel. The apparatus consists of a silvered brass oil-cylinder, fitted at base with an agate jet of standard bore. This agate jet is encased in a stout brass tube which is screwed at end and fits into the centre of outer vessel The outer vessel is of spun copper, lined on the outside with oak, and fits on to brass levelling stand. Two low temperature thermometers graduated 0-70° F., ball valve for closing agate jet, 50 c.c. flask, etc., as illustrated. Price complete, with thermometers, flask, etc., as illustrated, and certificate of verification by Mr. A. G. Berry, chief assistant to Sir Boverton Redwood DIRECTIONS FOR USE. The outer vessel or bath is packed with broken ice to a height roughly corresponding with that of the gauge- point in the oil-cup. The oil to be tested must be free from water, dirt, and matter in suspension, and should be maintained at a temperature of 32° F. for at least six hours immediately before it is tested. The thermometer is supported in the oil-cup by means of the clip; so that its bulb rests on the bottom of the cup, and in such a position that the flow of oil from the orifice will not be interfered with. £10 10 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 911 BAIRD &TATLOCK (LONDON) LTD. The oil-cup is filled with the cooled oil, so that the gauge-point is covered, and the apparatus is then trans- ferred to an efficient ice-chest of suitable design and the instrument levelled by means of the tripod-screws and spirit-level provided for that purpose. As it may be necessary to make more than one test, it will be found desirable to have at least half a pint of the oil in a stoppered glass bottle placed in the ice-chest with the instrument until required for use. Before commencing a test, the level of the oil in the oil-cup is brought exactly to the point of the gauge. A narrow-necked flask, of 50 cubic centimetres capacity to a mark on the neck, is placed beneath the jet and the ball valve raised and suspended from the thermometer-clip by means of the hook on the stem of the valve, a stop watch being started simultaneously with the lifting of the valve. During the period of testing, the temperature of the oil must remain constant at 32° F. The time of outflow for 50 cc. is noted, and the result given in seconds. If the oil-cup requires to be wiped out, tissue paper rather than cloth should be employed, as filaments of the latter may be left adhering to the surface of the vessel. The agate orifice must not be cleaned with anything which is likely to cause abrasion, and it has been found best to employ twisted tissue paper for the purpose. 5008 5008T Ice Chamber, for use with Sir Boverton Redwood's Viscometer (Admiralty pattern), to enable tests to be made at 32° F. The chamber is made of zinc, well insulated and fitted in oak frame, with glass panelled door, size of inner chamber 24 x 14 X 14 in. . . £12 10 CROSS STREET • HATTOTST GARDEN, E-C BAIRD &TATLOCK. (LONDON) LTD. 5009-5010 5009-5010 (Section) 5009s Viscometer, Sir Boverton Redwood's. The recognised standard instrument for testing viscosity of oils. This apparatus has been adopted by the Mineral Oil Association as its standard for measuring viscosity. Standardised by Mr. G. A. Berry, assistant to Sir Boverton Redwood. Price, complete with thermometers and certificate of verification, in portable mahogany case 5010s Viscometer as above, without case 5011s Thermometers for above, with N. P. L. Certificate (tested at every 10° F.) . . per pair 5012s Extra thermometers for temperature to 340° F. . . . . . . . . ,, 5013 Flask with mark on neck, 50 cubic centimetres capacity, for use with above apparatus each, 6d. ; per doz. Journal of Society of Chemical Industry, vol. v., p. 126. DESCRIPTION OF THE APPARATUS. The instrument consists of a silvered brass oil-cylinder, furnished with an agate jet, and surrounded by a copper bath. A copper tube, closed at the lower end, projecting at an angle of 45° from the side of the bath, near the bottom, provides a means of heating the bath liquid, and by the use of a revolving agitator, which forms part of the apparatus, the heated liquid rising from the copper tube can be uniformly distributed through the bath. The agitator carries a thermometer to indicate the temperature of the bath. The oil-cylinder is furnished with a stopper, consisting of a small brass sphere attached to a wire, the sphere resting in a hemispherical cavity in the agate jet. A short standard, attached to the oil-cylinder, carries a clip to support a thermometer in the oil. Inside the oil-cylinder, and at a short distance from the top, is fixed a small bracket, terminating in an up- turned point, which forms a gauge of the height of the oil level. The instrument is supported on a tripod stand provided with levelling screws. DIRECTIONS FOR USE. The bath is filled with a suitable liquid to a height roughly corresponding with the point of the gauge in the oil-cylinder. Water answers well for the temperature up to 200° F., and for higher temperatures a heavy mineral oil may be used. The liquid having been brought to the required temperature, the oil to be tested, previously brought to the same temperature, is poured into the oil-cylinder, until the level of the liquid just reaches the point of the gauge. A narrow necked flask, holding 50 cubic centimetres to a point marked on the neck, is placed beneath the jet in a vessel containing a liquid of the same temperature as the oil. The ball valve is then raised, a stop watch at the same time started, and the number of seconds occupied in the outflow of 50 cubic centimetres noted. It is of the greatest importance that the oil-cylinder should be filled exactly to the point of the gauge, after inserting the thermometer, and that the given temperature should be precisely maintained during the experi- ment, a difference of J degree F. making an appreciable alteration in the viscosity of some oils It is also essential £5 15 £5 0 0 £1 18 £0 12 £056 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 913 RAIRD dcTATLOCK (LONDON) LTD. that the oil should be quite free from dirt or other suspended matter, and from globules of water, as the jet may be otherwise partially obstructed. If the oil-cylinder requires to be wiped out, paper rather than cloth should be employed, as filaments of the latter may be left adhering. When oils are being tested at temperatures much above that of the laboratory, a gas flame is applied to the copper heating tube, and the agitator kept in gentle motion throughout the experiment. NOTE. — The jet should be carefully examined before the apparatus is used, and, if necessary, should be cleaned by passing a piece of soft string through it. The apparatus should be adjusted by means of the levelling screws, so that a spirit level placed on the top of the oil-cup shows it to be horizontal. METHOD OF EXPRESSING THE RESULTS. Sir Boverton Redwood recommends that the number of seconds occupied in the outflow of 50 cubic centi- metres of the oil under examination should be multiplied by 100 and divided by 535 (the number of seconds occupied in the outflow of 50 cubic centimetres of average refined rape oil at 60° F.). The resulting figures should then be multiplied by the specific gravity of tile oil under examination at the temperature of the experiment, and divided by 915 (the specific gravity of refined rape oil at 60° F.) ; the necessary correction for specific gravity being thus made, the final figures will express the viscosity of the oil, at the temperature of the test, in terms of viscosity of refined rape oil at 60" F. 5014 5015 5014s Engler's Viscometer, with verified measuring flask, capacity 200 cubic centimetres, and thermometers 10 to 50° C. and 10 to 150° C. .. 5015 Engler's Viscometer, standard pattern, designed by the Petroleum Congress, with measuring flask with two bulbs each 100 c.c., thermometers 10 to 50° C. and 10 to 150° C. £3 17 £4 15 CROSS STREET • HATTOTST GARDE1ST, E-C 914 BAIRD &TATLOCK. (LONDON) LTD. A-B. 5016 5017 )165 Kunkler's Viscometer, for testing the viscosity of fats, greases, etc., especially suitable for small samples, and for cylinder oils at 150° C. . . )17S Viscometer, Coleman-Archbutt's. Complete on stand, with burner, thermometer, etc. This instrument is an improved form of the well-known viscometer first used by Coleman about 1869. It nsists of a glass pipette contained in an outer water-jacket, with a funnel for pouring in hot or cold water, a be for running off water, and a stirrer for thoroughly mixing the water in the jacket. The neck at the lower il of the jacket is made narrow, a rubber stopper not more than -fa in. thick is fixed in it, and the jet of the lux tube projects through the stopper only fa in., and does not extend quite to the end of the neck. Thus e oil in the tube is surrounded by the water in the jacket until it has reached nearly to the end of the jet, and e temperature is maintained constant until the oil has passed out of the tube. The jet is protected from change temperature as well as from fracture by being contained entirely within the neck of the jacket. The efflux tube narrowed for a short distance above the jet, and four circumferential marks are etched upon it. The lowest zero mark is rather above the middle of the narrow portion ; the other three marks are on the wide portion and vide the tube above the zero mark into capacities of 25 cubic centimetres, 50 cubic centimetres, and 100 cubic ntimetres. The volume of oil used for a test may therefore be varied according to the viscosity and the quantity ailable. But the tube must be separately standarised from each mark, as the times of efflux of the different >lumes bear no simple relation to each other. The temperature is maintained constant by pouring hot or cold iter into the jacket, through the funnel, and running off the excess as often as required, using the stirrer ^quently. The temperature is indicated by a thermometer immersed in the water. The oil, having been brought about the desired temperature, is poured into the efflux tube, where the final adjustment is made by stirring th a thermometer, which is removed before the oil is run out. The jet is closed by a plug of soft wood, which now removed and replaced by the finger, and the level of the oil is adjusted exactly to the mark which it is sired to run it from. It is then allowed to flow out, and the time occupied in reaching the zero mark is measured • a stop watch, and compared with the time occupied by the standard oil to flow out under exactly similar cumstanccs. When it is desired to make a determination at 212° F., the temperature of the water is gradually iscd to about 180° F. by pouring in very hot water, and then the funnel is removed and replaced by a tube nnected with the metal boiler, and steam is blown in until the water boils. A short bent glass tube is provided ." the escape of steam. The length of the jet is about I in., and the diameter is such that 100 cubic centimetres re rape oil at 60° F. takes about ten minutes to flow out. £2 15 £3 3 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 915 BAIRD &TATLOCK (LONDON) LTD. 5018 5018s Vaporimeter, Archbutt's, as described in J. Veitch Wilson's Book on the " Analysis of Oils," complete with tube burner and thermometer about 18 in. long, 100 to 450° F. in single degrees, with N. P. L. Certificate giving corrections at every 50° 5019 5020 5019s Stop Watch, reading to fifths of a second. The recording pointer is started by pressing the knob, stopped by pressing a second time, and brought back to zero by pressing a third time, in oxidised steel case .. .. .. .. .. .. £11 5020s Stop Watch, reading to one-fifth of a second, 3 action, best manufacture, guaranteed correct, in silver plated case . . . . . . . . . . . . £2 10 14- -CROSS STREET • HATTOTSr GARDETST, E-C 916 BAIRD ^TATLOCK (LONDON) LTD. 5021 5023 5021s Vacuum Jacketed Glass Tubes as used in Hehner's bromine test for oils. Price without platinum wire. Size 4 by i in. inside . . . . . . t . . . each 5022s Thermometer for above, 10° to 75° C., in fifths (See article by Mr. L. Archbutt, F.I.C., Journal of the Society of Chemical Industry, April, l897. P- 309-) 5023s Apparatus for Testing the Viscosity of Glue, by Weiss £029 £040 £11 5 0 5024 5024s Wilson's Chromometer, for determining the colour of petroleum Price, with four standard glasses, Nos. i, 5, 10, 15, as below No. i = Water white. „ 5=Superfine white. „ io=Prime white. „ i5=Standard white. If required, additional glasses can be supplied between Nos. 5 and 10, marked 6, 7, 8, 9, and between Nos. 10 and 15, marked n, 12, 13, 14, at the extra price of 12/6 per glass. This instrument consists of two similar tubes, 16 in. in length, closed at each end by a screw cap carrying a stout glass disc. Light is reflected upwards through the tubes by a mirror, and is then by two pairs of prisms twice reflected, and thus brought into an eyepiece. One of the tubes is filled with the oil to be tested, and beneath the other, which is empty, a disc of stained glass is placed. On looking through the eyepiece, the field is seen to be divided by a sharp line formed at the juncture of the two pairs of prisms, the two halves of the field being tinted respectively with the colour of the oil and that of the standard. An accurate comparison can thus be made. The four standards representing the various grades of colour recognised commercially are prepared from Mr. Robert Redwood's standards. (See pp. 546, 547, vol. ii., Petroleum, by Sir Boverton Redwood.) £6 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &. TATLOCK (LONDON) LTD. 5025 (Fig. A) 5025s Walpole's Colorimeter 5025 (Fig. B) £1 12 i 5026s Glass Tubes with glass bottom cemented on, for above, large size . . . . each £0 5027s Glass Tubes with glass bottom cemented on, „ „ small size . . . . „ £0 WALPOLE'S COLORIMETER FOR THE TITRATION OF COLOURED FLUIDS Consists of a mahogany case with hinged front, and a white opal glass plate at bottom to reflect the light through the two pairs of tubes inside the case. The tubes consist of specially selected pieces of glass tubing of uniform diameter, with a base of clear glass fixed by means of an insoluble cement. The light reflected from the white opal glass plate shown in Fig. A passes upward through the glass tubes shown in Fig. B, and the two pairs of tubes can be compared in the ordinary way. It will be seen that in the general case, if the two columns match in colour, and if the upper tubes contain the pigmented fluids, and one of the lower tubes is colourless, the colour of the remaining lower tube will be the difference in colour between thfi two upper tubes. An example of the method of working may be described thus : — Equal quantities, say, 10 cubic centimetres of the coloured fluid are placed in A and B, and an indicator solution is added equally to c and B. In c is placed 10 cubic centimetres of a mixture of standard reaction to which it is desired to titrate. Finally, 10 cubic centimetres of distilled water is placed in D. To the tube B, standard acid or alkali is added till the colours seen looking down the two tubes, match. At that point, the colour due to the indicator in B is the same as that due to the indicator in c. That is to say, the contents of B have now the same reaction as the contents of the standard tube, subject to such corrections the particular case demands. Specific examples of the use of this instrument both for titrating' coloured fluids, and for the determination of H ionic concentration by the method of Friedenthal and Salm, as extended by Sorensen, may be found in the following literature : — G. S. Walpole, Proceedings Physiological Society, vol. xl., 1910, p. 27. G. S. Walpole, Biochemical Journal, vol. v., pp. 207-214 ' CROSS STREET • HATTCnST GARDETST, E-C 918 BAIRD &TATLOCK (LONDON) LTD. 5028-5030 5031 5028s Stammer's Colorimeter, for testing the colour of mineral oils, No. 3 pattern, with to read to 350 millimetres with three glasses 5029s Stammer's Colorimeter, for testing the colour of mineral oils, No. 3A pattern, scale to read to 290 millimetres with two uranium normal glasses 5030s Stammer's Colorimeter, for testing the colour of mineral oils, No. 7 pattern, with to read to 350 millimetres, with metal tubes and two uranium normal glasses 5031s Apparatus, for the distillation of mineral oils, Dr. Engler's pattern, complete . . PRICES OF SEPARATE PARTS. A. Iron mantle, with cover . . B. Burner, with regulation stopcock . . C. Mantle, for protecting flame D. Thermometer E. Oil reservoir F. Draining table G. Measuring flask H. Spanner I. Condenser metal . . J. Condenser stand . . K. Burette, 60 cubic centimetres L. Burette, 100 cubic centimetres M. Burette stand, with clamp N. Case for burette, etc. 0. Case for apparatus scale with scale £8 £9 £14 £10 10 10 5 10 0 0 0 0 £0 17 6 £120 £0 1 9 £0 16 6 £1 18 0 £076 £070 £007 £100 £046 £0 15 0 £0 16 6 £090 £0 11 0 £0 12 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. e^^ BAIRD &TATLOCK (LONDON) LTD. Fig. 3- Fig. I. Figs. 456. 5032-5033 5032-5033 5032s Dubosq Colorimeter, without vernier 5033s Dubosq Colorimeter, with vernier DESCRIPTION. Fig. i. Represents front view of apparatus. When in use the operator stands behind. Fig. 2. Represents back view, and shows the divisions and the vernier. Fig. 3. The path of the light inside the instrument. Fig. 4. Shows the appearance of the diaphragm seen through the eyepiece when the apparatus is regulated to zero. Fig. 5. Shows the same in use as Fig. 6 when an equality of tones has been obtained. THE PATH OF THE LIGHT (Fig. 3). The diffused light from a lamp or a monochromatic burner, after being reflected on to a mirror A, is separated into two beams, which penetrate respectively into the two tubes B, B. The right beam is reflected twice in the right half of prism K, penetrating into the eyepiece, it only affects the right half of the field ; the left beam does exactly similar, affecting only the left side of the field. No bright light is needed ; it is sometimes better to place before the mirror A a piece of ground glass. (A piece is supplied.) INSTRUCTIONS FOR USING. This instrument gives relative results. Place standard coloured liquid in left tube B. Place liquid to be compared in right tube B. Now lower the right tube D until it reaches what appears to be the most convenient point for estimation, which depends on the colour of the liquids ; now note the divisions on scale corresponding to the standard liquid. Lower the tubes D till they touch the bottom of B and the verniers g mark zero. Look through o, and then gradually move the apparatus till both half fields are equally illuminated ; now move screws E till equality of tone is produced. For two liquids the colour is inversely proportional to the density of the column of liquid traversed by the light and proportional to the quantity of dissolved matter. Example. — Suppose a liquid gives a reading of I2m5, and the standard is iom, we shall then have the following proportion : — Colour of liquid _ height of standard _ iom Colour of standard height of liquid I2'"5 ~ °' ' so the colour of the standard being represented by I, that of the liquid will be 0.8 To Clear Tubes B, Raise pistons D, take out tube B, unscrew ring c, take off the glass at bottom. The rest can be easily cleaned by means of a fine cloth. £10 £12 ) CROSS, STREET • HATTOTST GARDETST, E-C 920 BAIRD &TXTLOCK (LONDON) LTD. 5034 5035-5044 5034s Diaphanometer, designed by Dr. Konig, for determining the degree of turbidity and depth of colour of solutions .. .. .. .. .. .. £11 5 0 DESCRIPTION. This instrument consists of two immersion tubes : the light transmitted by the solution under examination passes through one tube (the right) , the other tube serving as a comparison. The light from both tubes is observed through one eyepiece, each tube lighting one-half the field, after the manner of a half shadow polarimeter. Discs of red and green glass are supplied, to be inserted in the left tube to cut down the light, until it is about equal to that transmitted through the other tube. A series of discs can also be introduced into the path between the left-hand tube and its prism ; these cut off from 10 per cent, and upwards of the transmitted light. The final comparison is made by raising or lowering the right-hand tube. Tables are given for converting the observations into percentages of turbidity or colour for white light, the number obtained actually denoting the percentage of light transmitted by the liquid under observation. The instrument is used in front of a window, the diffused light being reflected into the tubes by a ground-glass plate ; direct sunlight should be avoided. Standard glasses or solutions are not needed with the instrument. The strength of solutions of various coloured salts may be approxi- mately determined. 5035T Colorimeter (Autenrieth & Koenigsberger's), large model for chemists, colour, paper and textile manufacturers, and brewers. Length of wedge 16 centimetres . . . . £2 14 0 5036T Colorimeter, small model for doctors, pharmaceutical chemists, and preparers of chemical foods. Length of wedge 12 centimetres . . . . . . . . . . ..£240 5037T Colorimeter, small model, with two wedges, for determining Haematin and sugar . . £2 10 0 5038T Drinking Water Outfit, consisting of small Colorimeter with i gauged wedge each for ammonia, nitrous acid, iron, and i empty wedge with stopper for any other kind of colorimetric examination, also with light protection device, all parts in velvet-lined, polished wooden case . . . . . . . . . . . . . . each £5 15 0 5039T Drinking Water Outfit, consisting of small Colorimeter with light protection device, and i gauged wedge each for ammonia, nitrous acid, sulphuretted hydrogen, lead, iron, copper, and 2 wedges, all parts in velvet lined, polished wooden case . . . . each £710 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 921 BAIRD &.TATLOCK (LONDON) LTD. 5040T Small Colorimeter for Drinking Water with light protection device, 2 troughs, and i gauged wedge each for ammonia, nitrous acid and iron (without case, etc.) . . each 5041T Chemical Colorimeter, with only i gauged wedge for either chromium, copper, titanium, manganese, vanadium, iron, iodine, or copper, large model . . . . . . each 5042T Chemical Colorimeter, large model, with one empty stoppered wedge of 16 centi- metres to be calibrated by the user . . . . . . . . . . each 5043T Chemical Outfit, consisting of small Colorimeter with 12 centimetres gauged wedges for chromium, iron, iodine, copper, titanium, and vanadium, 2 troughs, all parts in velvet-lined, polished wooden case . . . . . . . . . . each 5044' Chemical Outfit, same combination as No. 5043, but with large Colorimeter and large wedges of 16 centimetres . . . . . . . . . . . . each ACCESSORIES AND SPARE PARTS. each A. 12 centimetre wedge, empty, for small colorimeter, not stoppered B. 15 centipietre wedge, filled but not calibrated . . . . . . ,, C. 12 centimetre wedge, filled and calibrated . . . . . . . . ,, D. 12 centimetre wedge, empty, stoppered E. 16 centimetre wedge, empty, for large colorimeter, not stoppered F. 16 centimetre wedge, filled, but not calibrated G. 16 centimetre wedge, filled and calibrated . . . . . . . . ,, H. 16 centimetre wedge, empty, stoppered . . . . . . . . ,, K. Spare trough for small model, usual size . . . . . . . . ,, L. Spare trough for small model, extra long (for ammonia and lead) . . „ M. Spare trough, small model, stoppered (desirable, but not absolutely necessary for iron) . . . . . . . . . . . . . . . . each N. Spare trough, for large model 0. Spare trough, extra long for large model (for ammonia and lead) . . ,, P. Spare trough, for large model, usual size, but stoppered . . . . „ Q. Reserve pipettes . . . . . . . . . . . . . . ,, R. Helmholz double plate, small . . . . . . . . . . ,, S. Helmholz double plate, large T. Subsequent adaptation of light protection device, if a colorimeter is to be adapted for examination of drinking water, inclusive of extra long trough and holder for it each Detailed instructions are supplied, with each colorimeter. A special wedge is required for each examination, and it is requested to state exactly what examinations are to be carried out on the apparatus, also whether the wedges are to be empty, filled, or filled and calibrated. Apparatus which are to be calibrated by the users, are as a rule, supplied with empty wedge, which can of course, be used for every kind of examination. £400 £2 14 0 £280 £7 10 0 £8 15 0 £060 £090 £0 16 0 £070 £070 £0 10 0 £0 17 0 £080 £023 £036 £0 £0 £0 £0 £0 £0 £0 3 6 4 0 £100 CROSS STREET • HATTOTST GARDETST, E;C 922 BAIRD &.TATLOCK (LONDON) LTD. 5045 Sectional Illustration of 5045 5045 5045s Thurston's Patent Oil Tester (improved design by W. H. Bailey). For general use, ij in. diameter of journal. For oil merchants, cotton spinners, engineers, etc. This machine is adapted for a wide range of pressure, and scales are provided on the pendulum for indicating the total pressure on the journal, and the corresponding pressure per square inch. To obtain the best results it is essential that each test should be made at the pressure under which it is proposed that the journal on which it is to be used shall run. The same quantity of oil should be used for each test. The Fig. 5045 machine should run at a speed of 2,250 revolutions per minute, which is equal to a speed of rubbing surface of 736 ft. per minute. The periphery speed of the journal of the Figs. 5045 and 5046 machines should be equal to the maximum periphery speed of the shafting or journals on which the selected oil is intended to be used. The figures on the arc P, traversed by the pointer attached to the pendulum, are such that the quotient of the reading on the arc divided by the total pressure read from the front of the pendulum at M, gives the " co-efficient of friction," i.e., the proportion of that pressure which measures the resistance due to friction. A printed table is furnished giving these co-efficients for a wide range of pressures and arc readings. To Determine the Lubricating Quality. — Remove the pendulum H H (see sectional illustration above) from the testing journal G G, adjust the machine to run at the desired pressure by turning the screw head K projecting from the lower end of the pendulum until the index M in front of pendulum shows the right pressure ; adjust it to run it the required speed. Throw out the bearings by means of the two thumb-screws on the head of the pendulum in the small machine, or by setting down the brass nut immediately under the head in the case of Figs. 5045 and 5046. Carefully slide the pendulum off the testing journal G G, and see that no scratching of journal or brasses takes place. Place a few drops of the lubricant to be tested upon the journal, replace the pendulum, and set the machine in motion, running it a moment until the oil is well distributed over the journal. Next stop the machine ; loosen the nut or the cams which confine the spring, and, when it is fairly in contact and bearing on the lower brass with full pressure, turn the brass nut or the cams fairly out of contact, so that the springs may not be jammed by their shaking back while working. Now start the machine again, and run until the behaviour of the oil is determined. At intervals of one or more minutes, as may prove most satisfactory, observe and record the temperature given by the thermometer Q, and the reading indicated on the arc p of the machine, by the pointer o. When both readings have ceased to vary, the experiment may be terminated. Remove the pendulum, first relieving the pressure of the spring, and clean the journal and brasses with exceed- ingly great care from every sign of grease, and be especially careful not to leave a particle of lint on the surfaces. A comparison of the results thus obtained with several oils will show their relative values as reducers of friction. Observe — ist. The pressure and speed of rubbing at each trial. 3rd. The readings on the arc of the machine. 2nd. The observed temperature. 4th. The calculated co-efficients of friction. To Determine the Liability of the Oil to Gum. — Allow the machine to stand with the journal wet with oil for 12 or 24 hours or more, as may be found necessary. Then start up and run a few moments until the reading on the arc P having fallen to a minimum, begins to rise again, then stop at once. Compare the minimum co- efficients thus obtained from the several oils to be examined ; that which gives the smallest figure will be least liable to gum during the period of time given to the test. To Determine Durability. — Proceed as in determining the lubricating quality, and apply say a drop for each 2 in. length of journal. Then start the machine. When the friction, as shown by the pointer o, has passed a minimum and begins to rise, the machine should be carefully watched, and should be stopped either at the instant that the friction has reached double the minimum, or when the thermometer indicates 212° F. This operation should be repeated until the duration of each trial becomes nearly the same ; an average may then be taken either of the time, of the number of revolutions, or of the distance rubbed over by the bearing, which average will measure the durability of that lubricant. Next, carefully clean the testing journal and proceed as before with the next oil to be tested. £9 18 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- A lubricant is valuable in proportion to its durability and its freedom from tendency to gum, and in proportion as it exhibits a low measure of friction. In making comparisons, always test the standard, as well as the competing oils, on the same journal, and under precisely the same conditions. An approximate value, by which to compare the oils, can be calculated, based on the assumption that they will have a money-value proportionate to their durability and to the inverse ratio of the value of the co-efficient of friction. Thus : suppose two oils to run, the one 10 minutes and the other 5, under a pressure of 100 Ibs. per square inch, and both at the same speed, and suppose them to give on test for friction the co-efficients o.io and 0.06 respectively. Their relative values might be taken at ^{ = I and £ = .833. If the first is worth say 100 pence, the second should be worth 83} pence. In many cases, however, about the same quantity would be applied by the oiler whatever oil might be used, and their values to the consumer would be in the inverse proportion of the values of their co-efficients of friction, i.e., as 6 in the above case is to 10, thus showing that it would be cheaper to use the latter if its cost is anything less than its relative value. N.B. — Be Exceedingly Careful of the Testing Journal : a scratch will modify the result. Scientific accuracy can only be attained by extreme care and cleanliness, and nicety ot measurement. See that all the drops used are of uniform size. Strain the oil through a muslin cloth before testing. Keep on hand a standard oil of known purity for comparison, weighing on a chemist's balance for fine work and using an apothecary's " dropper " for ordinary tests. A good way, also, of securing uniformity, is to draw a No. 8 wire, a few inches long, to a fine point ; dip it in the oil and allow it to drip half a minute, the succeeding drops will then be of very uniform size. Always relieve the spring from pressure when the machine is not in use. See that the compressing-screw is always well oiled. Whenever, by an}' carelessness or inadvertence, the journal loses its surface in the slightest degree, keep it running under light pressure until it is made right again. Move the bearing backward and forward two or three times on its journal, just before taking each reading to redistribute the oil. Hang a tackle or deferential pulley over the pendulum of the large machine, by which to lift it. 5046 5046s Thurston's Patent Recording Oil Tester, " Railroad and Steamship Pattern," with Mr. W. Worsdell's Improved Reciprocating Bearing, and facilities for testing bearings of different alloys 5047s Thurston's Patent Oil Tester, the Bathgate Standard Pattern, as first built for the Pennsylvania Railroad Co. Full size car axle, 7 by sf in., pressure as high as five tons ; also supplied to Messrs. Young's Mineral Oil Works, and many railway and other com- panies, without recording arrangement. This pattern is a small model of Fig. 5046 £90 0 0 £53 0 0 CROSS STREET • HATTCXN GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD." 5048 5052 Mackey's Cloth Oil Tester. 5048s Apparatus complete, with thermometer, 6-wire gauze cylinders, i doz. pkts. cotton wool, stand burner, and measure 5049s Thermometer, Cent, and Fahr. scales . . . . ' . . 5050s Wire gauze cylinders, per doz. 5051s Seven-gramme pkts. cotton wool This apparatus has been designed by W. W. M'D. Mackey, F.I.C., of Leeds, to meet the want of an efficient ami quick method for testing the liability of oils to develop heat spontaneously under the conditions obtaining in cloth mills. The method is essentially a comparative one, so that the instructions given must be rigorously followed if results comparable with those of other operators are to be obtained ; and it is recommended that before proceeding to the testing of actual samples, a few experiments be first made, say, with a good fresh olive oil and a cotton seed oil as representing a dangerous oil, and the results obtained compared with those given in the tables. 5052 Flask for the quantitative determination of essential oils in drugs and spices (See /. S.C.I., p. 936, Oct. 1900.) £2 10 0 £076 £040 £0 1 0 each £036 APPLIANCES USED ON BOARD PETROLEUM STEAMERS FOR MEASURING OIL TANKS, AND TESTING FOR INFLAMMABLE VAPOURS. 5055T Redwood's Patent Water-finder, in mahogany case, with one dozen water-finder papers £3 13 0 5056T Tin Case, containing 10 dozen water-finder papers, specially prepared . . each £0 13 6 5057* „ „ 20 „ „ „ „ „ £190 5058* „ „ 50 , „ . . ., £3 15 0 5059T „ „ 100 „ „ „ „ .,,£700 5060* Sixty-Feet Steel Tape, marked & in., in leather case . . . . ..£150 5061T Redwood's Standard Gun-Metal Weight, with ebonite indicator . . . . . . £176 5062T Ebonite Indicator, with set screw for fixing on steel tape . . . . . . . . £086 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &L TXTLOCK. (LONDON) LTD. 5063 5063T Redwood's Inflammable Vapour and Gas Detector, with long flexible suction tube, guaranteed to detect and accurately measure, by means of a hydrogen flame, small percentages of inflammable gases or vapours . . . . . . . . . . £43 DESCRIPTION OF THE APPARATUS. The appliances (see figure) consist of the testing lamp A, the reservoir of compressed hydrogen B, and the sampling vessel c, in which the sample of air for examination is collected. The lamp is so constructed that flame cannot travel from the jet to an inflammable or explosive mixture in the sampling vessel. The chimney, which is partly of metal and partly of glass, fits air-tight when in the position shown in the illustration, butmay be raised to light the hydrogen flame or admit air. To facilitate the adjustment of the size of the hydrogen flame the chimney is fitted with a sliding shutter, which is raised when working with the larger flame and lowered when using the smaller. Attached to the base of the lamp is a telescopic support for a cloth which envelops the head of the observer, and excludes light when the testing apparatus is used in an undarkened room. The hydrogen reservoir is one of the cylinders ordinarily employed for compressed gas, and holds 5 cubic ft., which is sufficient to supply the flame for at least ten hours. The collecting vessel consists of a compression pump, with metallic spring piston lubricated with plumbago, surrounding which is an annular space in which the sample is compressed to 30 Ibs. per sq. in., a spring valve opening at that pressure being provided. The vessel is fitted with inlet and outlet cocks, unions, and a pair of hinged brackets on which the operator stands while working the pump. " Laboratory Book of Mineral Oil Testing," by James A. Hicks (late Chief Chemist to Sir Boverton Redwood). Price 2s. 6d. 3 0 CROSS STREET • HATTO>J GARDETST, E-C BAIRD &. TATLOCK (LONDON) LTD. Section XII. -v A _* -x ATER>^M,Y$I$ APPARATUS ii Apparatus for Analysis of Sewage Effluents 927-933 5)RCVTIO-N XIII. BaaKasi m m XIV Dyeing of Leather XV Apparatus for Testing Paper Pulp, Paper, • -. 14, CROSS STREET. HXTTON GARDEN. EC BAIRD & TXTLOCK: (LONDON) LTD. The following are the different Sections in oui Catalogue. Those marked * are also printec separately. Section No. 1.* Laboratory Fittings 2.* Bacteriological Apparatus 3. Chemical Physiology Apparatus 4.* Microscopes and Microscopical Accessories 5.* Balances and Weights 6.* Chemical Apparatus 7.* Botanical Apparatus 8. Gas Analysis Apparatus 9." Milk Analysis Apparatus 10. Refractometers 11.* Oil Analysis Apparatus 1 2. Water Analysis Apparatus 13. Cement Testing Apparatus 14. Leather Testing Apparatus 15. Paper Testing Apparatus 16. Physico Chemical Apparatus 17.* Pyrometers 18.* Calorimeters 19.* Seed and Soil Analysis Apparatus 20.* Spectroscopes and Polariscopes 21. Volumetric Apparatus 22. Anatomical Models 23. Meteorological Apparatus 24.* Assay Apparatus 25.* Chemicals Pages Nos. 14.5 57,16 162.19 193.32 321.38 383.81 817*84 843.8? 887. 8< 895 .9( 903^9: 927-9: 934-9 947 -9' 950^9 952.9 977.10 1007.102 1023.102 1043.108 1079.107 1088 1106 1125.112 1187*126 115 14- -CROSS STREET • HATTCTK GARDETST, E'C BAIRD &. TATLOCK (LONDON) LTD. SECTION 12. Water Analysis and Apparatus for Testing of Sewage Effluents. » I 5064 5064s Set of Apparatus for Testing the Hardness of Water, etc., in varnished wooden cabinet, with lock, key, and handle CONTENTS. A. Aspirator, 2-litre capacity, filled with distilled water. B. Bottle, 2-litre capacity, filled with soap solution. Indiarubber cork at top and bottom of aspirator, tube and clip at bottom. Indiarubber cork, with tubes and blowing ball, c. Bottle, 8 oz., fitted with indiarubber cork and pipette, containing methyl orange. D. Two Burettes, 25 cubic centimetres, graduated in jVths of a cubic centimetre. E. Bottle, 16 oz., fitted with indiarubber cork, containing acid " A." F. ,, „ ,, „ „ „ " B." G. Shaking Bottle, 6 oz., marked 35 cubic centimetres and 70 cubic centimetres. H. Porcelain Basin No. 3 R.B. I. Bottle, non-actinic, 10 oz., corked, containing i per cent, silver nitrate solution. J. 100 cubic centimetres Measure. K. Stirring Rod, 4 in. long. L. Filter Paper, 1 1 centimetres, 595 M. Funnel 3 in. DIRECTIONS FOR USE. In making a test for hardness, fill the shaking bottle up to the 70 cubic centimetres mark with the water to be examined, then, by means of the blowing ball, fill the burette with soap solution until the zero mark is reached. ' In the event of too much soap being forced into the burette, the excess may be run off by means of the stop- cock. All is now ready for proceeding with the test which is as follows : — • £326 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 927 BAIRD ^TXTLOCK (LONDON) LTD. Hold the bottle containing the sample in the left hand, and place it immediately under the end of the burette, then add the soap solution, a few drops at a time, by cautiously opening the stopcock, taking care to exercise no undue pressure as that is apt to cause the stopcock to jamb. After each addition, place the stopper in the bottle, and shake vigorously. At first any lather produced will disappear rapidly, but towards the end of the operation the lather will show a tendency to persist, and the bottle should then be placed on its side after each shaking, to present as much surface as possible. The test is complete when this lather remains for five minutes without breaking. During the test a guide to its progress may be gauged from the sound of the solution on shaking. While the water is still hard, the sound is metallic, becoming less distinct on nearing the completion of the test, and eventually giving place to a soft sound. When the test is completed, read off the number of cubic centimetres on the burette. This will give the degrees of total hardness direct. Say, for example, that the burette showed four large divisions or cubic centi- metres, and four small divisions or tenths of a cubic centimetre, then the reading would be 4.4 grains per gallon. Should the sample use more than 7 cubic centimetres soap solution, take only 35 cubic centimetres, or half the quantity, and dilute to the 70 cubic centimetres mark with the distilled water supplied. As distilled water itself shows a reaction with soap solution, i cubic centimetre must be deducted from the test made with the diluted sample. The result is then multiplied by two, as only half the quantity was taken. Example. — 5 cubic centimetres soap solution used in testing diluted sample, distilled water (35 cubic centi- metres) used I cubic centimetre soap, therefore 5 c.c.-i c.c. =4 c.c., 4 c.c. X2 c.c.=8 c.c. or eight degrees of total hardness. To find the temporary hardness, i.e., the carbonates of lime and magnesia held in solution by carbonic acid, the bottle labelled " Standard Acid A " is used. The estimation is conducted as follows : — By means of the 100 cubic centimetres measure take 70 cubic centimetres of the sample and transfer to the porcelain basin, then fill the other 25 cubic centimetres burette with the acid A, and adjust to the zero mark as before. Add two drops of the methyl orange solution to the sample in the porcelain basin, and stir cautiously by means of the stirring rod until the solution is uniformly coloured. Then add the acid solution from the burette, a few drops at a time, and stirring after each addition until the colour changes to a faint pink. At this point the carbonates have been neutralised by the acid, and the reading on the burette will represent the temporary hardness of the sample. Example. — Total hardness found by soap solution 8 cubic centimetres, temporary hardness found by acid A=4.i cubic centimetres. Therefore 8-4.1=3.9, a figure which represents the permanent hardness of the water in grains per gallon, or the salts of lime and magnesia other than carbonates in solution. 2. — Strength ot Lime Water by means of Standard Add B. Titrate 35 cubic centimetres of the lime water with Standard Acid B, as in estimating temporary hardness. To produce a pink colour with methyl orange, 16.2 cubic centimetres should be required. 3.— Silver Nitrate Solution for testing if correct quantity ot lime has been added. Place a little of the sample of water in a test tube and add a few drops of the silver nitrate solution. If the solution turns brown, excess of lime has been added ; if the colour is milky white, insufficient lime is present ; but if only a pale yellow colour is apparent, then the correct proportion of lime has been introduced. 5065 5065 Dr. Adeney's Apparatus for observing the rate of absorption of oxygen by polluted water and other fermenting liquids. Price complete with I.R. blower in polished mahogany case It is now agreed that the quality of a sewage effluent can best be ascertained by determining the rate at which it takes up dissolved atmospheric oxygen, after the suspended matters have been removed, and this apparatus has been designed for the purpose. Its form will be understood from the above sketch, full descriptive circular on application and with each instrument. £1 10 CROSS STREET • HATTOTST GARDETST, E-C 928 BAIRD &TM1OCK (LOlSfDON) LTD. 5066 5067 5068 5066 Bottles for Water Samples, square, capacity ij litre, with ground labels for notes each £036 5067 Nickel Dish, with cover and inner dish for water analysis . . . . . . . . £076 (See Wanklyn's " Water Analysis," loth edition, p. 24.) 5068 Separator, for minerals, with ground-in rod and cap, capacity 150 cubic centimetres . . £056 5069 5070-5075 5069s Apparatus for extraction of gases dissolved in water, designed by Mr. Sidney Harvey . . £215 For description see Kenwood's " Public Health Laboratory Work," 1903 Edition, pp. 140-143. Water Analysis Apparatus, Bischof's (see Sutton's " Volumetric Analysis," gth edition, p. 428). 5070 Copper vessel on stand . . . . . . . . . . . . . . each £011 5071 Glass jar or cover .. .. .. .. .. .. .. £02 5072 Glass basins . . . . . . . . . . . . . . . . £00 5073 Glass flasks with ground tube . . . . . . . . £04 5074 Retort stand with two rings .. .. .. .. .. ,. £03 5075 Complete Apparatus as figured . . . . . . . . . . „ £126 929 BAIRD &TATLOCK (LONDON) LTD. 5076 5079 5076 Distillation Apparatus, for water analysis, as used in the Metropolitan Water Board Laboratories. Stand 12 by 6 in., with rod screwed in centre, ring and gauge for supporting flask, flask of resistance glass, stoppered, 2 litres capacity, and Cribb's pattern metal condenser . . . . . . . . . . . . each 5077 Extra Flasks, stoppered, 2 litres . . . . . . . . each, 4/6 ; per doz. 5078 Extra Flasks, stoppered, i litre . . . . . . . . „ 2/6 ; 5079 Glass Vessel, with rod and cap for collecting sediment in water, English colourless glass, as recommended by Dr. Wynter Blyth . . . . . . . . . . each £1 1 £2 12 £1 8 £096 5080 5081 5080 Stand, of teak, with various size holes for test tubes. This stand was devised by Dr. Houston, of the Metropolitan Water Board, to take all the series of test tubes of media required for a complete analysis of water . . . . . . . . . . . . each £030 5081 Absorbing Vessel, devised by Prof. Letts for dissolved oxygen in water determinations, capacity J litre . . . . . . . . each £050 (See Government Blue Book on Sewage Disposal, Appendix VI., p. 222.) CROSS STREET • HATTOTST GARDETST, E-C 930 BAIRD &. TATLOCKL (LOM)ON) LTD. •••••••I •«•!•• Ill 5084 5082 5083 5082s Sampler for taking samples of water from a depth, with weight and glass tube Extra glass tube, exhausted ready for use . . . . . . . . . . per 5083 Paper Squares, with square black spots printed on, as used for the turbidmetric estimation of magnesia and sulphates in water, as recommended by Dr. Thresh, per doz., 6d. ; per gross 5084s Pair of Tubes on Stand, for comparing the colour of water, with white and mirror glass reflectors £0 10 6 £0 10 0 £056 £2 15 0 5085 5085 Tidy's Tubes for water analysis, glass tubes, with brass screw caps and glass ends. Sizes . . 24 by i 24 by 2 in. Price . . . . . . . . 9/6 15/- each. i i 5086 5086 Colorimeter, for testing the colour of water, as devised by \V. T. Burgess, Esq., F.I.C. .. (See Analyst, vol. xxvii., No. 319, October, 1902.) DESCRIPTION OF BURGESS' COLORIMETER. The colorimeter consists of two tubes, each 2 ft. long, placed in a horizontal position, one being filled with the water to be tested (tube A) and the other with distilled water only (tube B) . Light is reflected from an opal glass plate at c, and passes through both tubes. A mirror placed at an angle of 45 degrees reflecting the light upwards, thus enabling the observer to compare the tints of the contained waters at a point about 10 in. above D. By means of a mask no light except that passing through the tubes can be observed. Over the mirror is placed a platform p, with holes supporting two short cylinders E and F. A few cubic centimetres of distilled water are placed in F (which is over tube A), and a standard colour solution is run into E until the depth of colour is the same in both. The amount of standard solution required to be added is recorded in millimetres, and may be read off directly from a scale on the side of E, or by immersing a millimetre rule in the liquid. The standard solution contains I gramme pure crystallised cobalt sulphate and 0.05 gramme potassium bichromate per litre. £350 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 5087 5087s Dr. Adeney's Mercury Pump and Apparatus for the extraction and collection of dissolved gases in water. Price complete, mounted on teak stand with brass fittings, nickel-plated The pump proper consists of two glass bulbs A and B, of 50 and 20,0 cubic centimetres capacity respectively. A is closed by a Friedrich's two-way stopcock c, by means of which the pump can be connected or disconnected through the branch tubes a and b, with the laboratory flask F, or gas pipette, 150 cubic centimetres capacity, D. The bulb B is constricted and is continued downwards and bent twice at right angles and closed by a Friedrichs' stopcock K, as shown in the diagram. The mercury reservoir H is connected by rubber tubing to the pump by means of the side tubulure just below the stopcock K. To work the apparatus, the pump and branch tubes are filled with mercury ; the condenser E is fitted in position, as shown. A little distilled water, with or without the addition of a little sulphuric acid, as the experi- ment may require, is put into the flask A and boiled. The flask is then fitted by means of a rubber cork to the lower end of the condenser, and exhausted of air by means of the mercury pump in the ordinary way. When exhausted, the gas pipette D is removed by lowering the support d ; and the end of the branch tube from the pump, thus freed, is dipped under the water to be examined ; 50, 100, or 250 cubic centimetres of the water are drawn into the bulb A and B by lowering the mercury reservoir. The measured volume of water is then allowed to flow into the laboratory flask F, when it is boiled in vacua. £14 0 932 EPS? BAIRD &.TMXOCK (LOM)ON) LTD. The IB vessel, containing the water, is removed from the end of the branch tube, and the latter fitted with a short biece of thick walled rubber tubing, to serve as a collar. The gas pipette is restored to its position, with its funncl- .haped mouth pressing against the rubber collar ; this can easily be effected by means of raising the pillar support >f the table. The connection can be made air-free and air-tight without difficulty. The dissolved gases in the vater previously transferred to the laboratory flask F can be extracted in the ordinary way and stored in the ;as pipette D. When this operation is completed, the gas pipette is removed and attached to Adeney's apparatus or experiment and analysis. 5088 088s Dr. Adeney's Apparatus for the experiment and analysis of dissolved gases. Price complete on teak stand with brass fittings, nickel-plated .. .. .. £14140 The apparatus consists of burette A, an open pressure tube B, and adjustable mercury reservoir, and gas iptttes, all connected together as shown in the diagram. The burette is closed by means of a two-way Friedrichs' topcock, by means of which it can be connected or disconnected through the capillary branch tubes a and b ;spectively, with the gas absorption pipette c, containing potash or pyrogallic acid for the absorption of CO,, or >a, as may be required, and with the gas pipette D, containing dissolved gases. The gas pipette D is fitted with latinum wires, and can be used as an explosion pipette, when required. E is a Bunsen barometer. 089s Flasks F in above illustration, complete with ground in stopcock with funnel tube each £076 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD & TATLOCK. (LONDON) LTD, SECTION No. 13. Apparatus for Testing Cement. 5090 5090T Faija's Cement Gauger, with copper pan, gun-metal stirrers, and fittings. Will gauge at one operation from 2 to 4 Ibs. of cement By the use of this machine the cement can be reduced to the proper consistency for forming into briquettes in considerably less time, and with much less water, than is possible by even the most expert hand gauging. Consequently better and more regular results are obtained when testing the briquettes, and better comparative results can be obtained, as the discrepancies due to the skill of different operators is reduced to a minimum. The ordinary sized gauger will gauge at one operation from 2 Ibs. to 4 Ibs. of cement £4 1 5091 50911 Faija's Apparatus, for determining the soundness of cement in a few hours. Made of copper, and fitted with gas burner or lamp, thermometer, etc., complete. Improved form £3 CROSS STREET • HATTCTSr GARDEIST, E-C 934 BAIRD &TATLOCK (LOTMDON) LTD. 5092 >092T Falja's Hopper, for determining the weight per bushel of cement. This machine is arranged so that the hopper into which the cement to be weighed is put has no direct communi- ation with the bushel measure which is placed under it, but by turning a handle the cement is wormed to an pening immediately over the centre of the measure, and the cement therefore falls into it at a uniform pace, nd fills it to a uniform density, thus ensuring an absolute comparative determination between the weights of ifierent cements. Price, with bushel measure £9 15 0 5093 5094 093* Needle apparatus to ascertain the time of setting 094T Apparatus for ascertaining the temperature of cement during setting . . £1 10 0 £0 15 0 CHEMICAL AND, SCIENTIFIC APPARATUS AND PURE CHEMICALS- f BAIRD &.TATLOCK (LONDON) LTD. Uai 5095-5106 Cement Testing Machine, British standard pattern. This apparatus consists of a japanned cast-iron column, which carries two levers, the combined leverage of which is i to 50 — that of the longer being i to 10, and that of the shorter i to 5. Each lever has three hardened steel knife edges acting upon hardened steel concave bearings, so that an extremely accurate balance is obtained. The short arm of the upper lever is provided with a movable counterpoise, to secure the correct position of the levers, which is indicated by a mark on the upright catch at the top of the column. At the extremity of the long arm is suspended a small brass frame to carry the shot bucket. On the lower lever, near its fulcrum, is suspended the upper clamp or clip for holding the briquettes. The lower clamp is fixed to the base of the column and adjusted by means of a screw. To make a test, the cement briquette is taken out of the water, dried, and put into the clamps, which must be accurately applied to the sides of the briquette, and the screw applied until the upper edge of the long lever is opposite the mark on the upright catch. Fine shot is then poured from the self-acting short-run into the bucket suspended from the long lever until the briquette breaks, when the supply of shot is instantly cut off. The breaking strain per square inch is thus exactly fifty times the weight of the bucket and shot ; but to avoid all calculation and possible risk of error, a spring balance with a special dial is supplied, upon which the bucket and shot are weighed and the exact breaking strain of the briquette at once shown. All parts of the apparatus are highly finished, the polished iron and steel portions being nickel-plated to prevent rusting, if exposed to damp. 5095T Double lever machine 5096T Automatic shot-run, bucket and stand 5097T 12 Ibs. shot ...... 5098T English spring balance 5099T 6 brass moulds of i square inch section with springs . . 5100T 6 „ „ ,, held together with screws 51011 Spatula with knife 5J02T Can ...... 5103T 6 iron plates for moulds . . 5104T Brass sieve boxes with 5,776 and 32,400 meshes per square in., 4^ in. diameter . . 5105T i brass sieve box „ „ ,, ,, 6 in. 5106T 2 sieves, 400 and 900 meshes per square in. for the standard sand £0 1 £0 1 £1 J £0 ] 93 fi BAIRD &.TATLOCK (LONDON) LTD. 8 I 5107-5112 Cement Testing Machines and Appliances, as used by the Admiralty, War Office, Home, Indian, Colonial, and Foreign Governments, County and other Councils, Cement Manufacturers, Railway and Harbour Works, Builders, Contractors, etc., etc. The aim in the construction of all these machines has been to secure the most accurate and undeniable results, with absolute permanence and non-interference of the hand of the operator : thus, all spring and screws are dispensed with, and the simple steel lever, and vernier (with weight attached), travelling on rollers, adopted ; the vernier being traversed along the lever by a cord, passing over pulleys fixed to the standards, the hand not touching or in any way affecting .the lever during testing. To make this more unquestionable, in addition to the speed-reducing wheel and pinion, an automatic regulator can be added. There is no use made of either Water, Shot, Compound Levers, Spring Balances, Glass Tubes, or any other objectionable parts, liable to give a multiplied error, or to break, or that is in any way uncertain and unreliable in its action. They can at any time be easily tested for accuracy by simply hanging on any known weight (to the top clip for holding briquette) and taking the reading of the vernier. The reading of these machines are in Ibs., but the lever can be divided into any scale or foreign measure required. The shape of the briquette mould and clips is that of the British Standards Specifications form, but moulds, etc., can be made to any design and to any size section required. INSTRUCTIONS FOR FIXING AND USING AUTOMATIC REGULATOR. The Automatic Regulator has been designed to give a uniform rate of travel to the vernier, so that all tests are made at an equal number of Ibs. per minute, which the Engineering Standards Committee have fixed at 500 Ibs. ; but this can be altered to any speed required by means of a cock in piston. It is also self-acting, and when test is started, needs no interference whatever, and directly the briquette breaks the wire cord is held fast by means of clutch, or break, until released. To fix the Automatic Regulator, fasten the brass tube to floor underneath the pulley marked 2, so that the weight w just clears, and fill the tube with clear thin lubricating oil ; attach the long cord to left-hand side of vernier, pass round pulley 4 on top of pillar A, and back and over pulley 2, down under pulley 5, and upwards round No. i, and down again to loop at 5, attach the short cord to right-hand side of vernier, pass it over and twice round the pulley 3 to prevent slipping, and attach ball hook. To use Automatic Regulator, see that vernier is at commencement of scale, then place briquette into its place, tighten by the wheel R, until the strain is sufficient to lift the lever well above the zero line on standard E, then hang on brass weight w, which will at once commence to move vernier along the lever ; see that the vernier weight does not rock while travelling. To commence another test, remove weight w, lift lever by means of lifter, which is fixed to standard E, then press on the cross handle at top of piston rod, which will let piston down gently, and return vernier to commencement of scale, and proceed as already described. INSTRUCTIONS FOR MAKING BRIQUETTES. Mix the cement to be tested with as little water as possible, consistent with perfect homogeneity, and having laid the mould on a flat surface, or on the iron plate supplied for the purpose, fill it with the cement as mixed, pressing it well in with the spatula or trowel, and scrape the top flush. When set, take the briquette out of the mould caiefully, and place it still on the flat plate in water for seven days, or for a longer or shorter period, as required. It will then be ready for testing. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 937 BAIRD &. TATLOCK (LONDON) LTD. PRICES. 51071 No. i, with slow motion to move vernier and weight, reading from o to about 1,800 Ibs. with stand, ball and socket motion clips for testing i| in. briquettes. This machine is also suitable for testing i in. briquettes . . . . . . . . . . . . £28 0 0 5108T No. 2 Improved ditto, including Automatic Regulator, reading from o to i ton, with ball and socket motion clips for testing both i in. and i £ in. briquettes . . . . . . £35 0 0 5109T No. 3 Improved, same design as No. I, but with shorter beam and closer scale and 2 rows of figures, reading from o to 1,500 Ibs. on bottom row and 300 to 1,800 Ibs. on top row, including ball and socket motion clips for testing both i in. and i£ in. briquettes. This machine is made to supply the demand for a cheaper ii in. machine and for the Colonial market . . . . £24 0 0 5110T No. 4, for testing i in. briquettes. A cheap form of machine suitable for builders, etc., reading from o to about 1,000 Ibs., on ash top without legs, with ball and socket motion clips £12 10 0 5111T Legs to ash top for No. 4 extra £0 15 0 5112T No. 4 Finished, reading from o to 1,000 Ibs., on ash top with legs. This is the same as the No. 4, but all the parts are worked up, finished and lacquered, with ball and socket motion clips £15 5 0 5113* Automatic Regulator, extra £4 10 6 5114T Ball and socket motion Clips for i in. briquettes weighted to fit Nos. i or 3 Machines . . £1 15 0 5115T Gun-Metal Mould for if in. briquettes, held together with thumb screws £1 15 0 5116T Gun-Metal Mould for i in. briquettes, held together with thumb screws £0 12 6 51171 Iron Plates for above moulds . . . . . . . . . . 4d. and £0 0 6 5118T Nest of 6 moulds, i in. section £3 15 0 51 19* „ 5 £3 3 0 5120T „ 4 £2 12 6 5121T „ 3 £2 2 0 ACCESSORIES FOR MACHINES Nos. 5107-5112. 51221 Sieves, wood rim, brass gauze, up to 80 meshes, per in. linear £0 5 6 5123T „ 100 £0 7 6 51241 „ 120 „ „ £0 10 6 5125* „ 150,180,200 „ £0 12 6 5126T 7 in. diam. brass rim sieves, 76 and 180 mesh, with receiver and cover . . £1 14 0 5127T 7 in. „ ,, ,, 180 mesh, with receiver and cover £1 5 6 5128T 7 in. ,, „ „ 180 £0 16 6 5129T Balances and weights. See pages Nos. 321-381. 5130r Specific gravity bottles. See page No. 945. 5131T Vicat Needle Apparatus for ascertaining the beginning of hardening and the time of setting, also the correct consistency of cement £1 15 0 5132T Ditto, with dashpot £2 10 0 51331 Extra mould for above £0 7 6 5134* Weighted needle for testing setting time, revised pattern £0 12 6 5135T ^s£, One-tenth Bushel Measure, copper £0 I 14 ^M 0 X E 14 • CROSS STREET • HATTOW GARDEN, E •C- I 938 BAIRD & TATLOCK. (LONDON) LTD. • i fia 5136T Filler for above, with Stool £0 12 6 51371 Bushel Measure — Standard £180 5138T Half-Bushel Measure— Standard . . £100 5139T Stanger's Hopper for filling Bushel Measure for Weighing £330 5140T Platform Weighing Machine for weighing Bushel of Cement up to 2 cwts. £330 5141T Spatula for pressing Cement into mould £036 5142r Rammer £036 5143T Trowels, 8 in. . . £036 5144T Trowels, 6 in. . . £030 5145T Scoop, tin £0 1 6 5146T ,, copper . . £046 51471 Glass Measure for Water, divided to decimal of one pound and ozs. £036 5148T „ „ divided into 100 parts for percentage of residue £036 5149r „ Plates, 9 in. by 9 in. by f in. £0 1 0 5150T „ „ 6 in. by 6 in. by J in. £006 5151T Glass Test Tubes, 6 in. by i in. . . . . . . . . . . per doz. £0 1 2 5152T „ ,, 4 in. by fin. .. .: . . £008 5153T „ „ 13 in. by i£ in. . . £060 5154T Water Trays, wood-zinc lined, 2 ft. by 9 in. by 2 in. deep £076 5155r „ „ „ „ 2 ft. by i ft. by 4 in. £0 10 6 5156T Slate Slabs for making briquettes upon, 2 ft. by i ft. 6 in. by I in. £076 51571 „ „ „ „ 2 ft. by 2 ft. by i in. .. £0 10 6 5158T Transverse Testing Appliance, 12 in. by 3 in. by 3 in. £660 5 1591 Iron Mould for ditto £2 10 0 5160T Arnold's Patent 5-Mould Apparatus £900 51611 Extra Mould for Arnold's £1 1 0 5162T Mechanical Mixer £4 12 0 5163T Hydraulic Machines for Crushing Cement Cubes . . . . . . from £40 0 0 5164T Compound Lever Crushing Machine to 50 tons £66 0 0 5165T Iron Mould for Cubes, 100 c.c. or 2 in. . . . . . . . . . . each £1 1 0 5166T „ „ 500 c.c. or 3 in. . . . . „ £150 51671 „ „ 1,000 c.c. or 4 in. . . . . . . . . . . „ £1 10 6 5168T Hot Water Baths for briquettes, complete . . . . . . . . . . from £390 5 169T Thermostat for Hot Water Baths .. £1 10 0 5170T Deval Bath for 6 briquettes, ij in. section . . £550 5171T „ 6 i in. £4 10 0 5172T Bauschinger Apparatus for Testing Expansion £10 0 0 51731 Chatelier's Mould, brass £020 5174T „ „ nickel £036 5175T „ Glass plates . . £001 5176T ,, Boiler, copper with loose corrugated tray £200 51771 „ Boiler, tin „ „ „ ...... £0 17 6 5178T Millimetre Steel Rules for Expansion . . . . . . . . 4 in., I/- ; 6 in. £0 1 3 5179r Thermometers . . . . . . . . . . . . . . from £020 — /S^=, a CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS, fll 939 BAIRD &TATLOCK (LONDON) LTD. 5180T Thermometers, 30° to 120° F. in wood cases, 7 in. or 10 in. long 51811 „ 30° to 220° F. ,, „ 12 in. 5182T Taper Bulb Thermometers for Cement 5183T Apparatus for determining Temperature of Cement during setting 5184T Bohme i Hammer Apparatus and moulds for i in. briquettes. See No. 5201 5185T „ 2 ,, ,, „ „ No. 5201 £056 £056 £056 £0 17 6 £18 10 0 £25 0 0 5186T Cement Sampling Tins, lever top . . . . per doz. 6/- and £090 With Dashpot. 5187 5188 5189 5187r Weighted Needle for testing cement For testing of the setting time of cement, it weighs 2j Ibs. and has a removable hardened steel point of -fa in. square section. Mix a pat of cement about 6 in. x 6 in. x £ in thickness, place upon a glass or iron plate, and hold needle by the edges of loose washer, taking care that fingers do not press against the stem. Place needle on the cement pat and lower the loose washer, this leaves the needle free to penetrate the cement. The setting time is from the moment of gauging until needle fails to make any impression on the cement pat. 5188T Vicat Needle to British Standards Specifications. For ascertaining the commencement of hardening and time of setting, also the correct consistency of cement 5189 Vicat Needle as above, with dashpot INSTRUCTIONS FOR USE. Gauge 14 ozs. of neat cement with the correct quantity of water into a stiff paste as quickly as possible, fill circular brass or vulcanite mould, place same on stand as shown in sketch; the moment at which the needle of i square millimetre section and 300 grammes in weight fails to penetrate to the bottom of the paste is the commence- ment of the hardening. To get the full strength of the cement it should be worked and used within the time of the begin- ning of gauging to commencement of hardening, To find the correct consistency ol the Cement. — Remove the needle of i square millimetre and replace by cylinder B of I centimetre in diameter. Cement is gauged and the brass or vulcanite mould filled as quickly as possible, the consistency being correct when the piston remains at a height of six millimetres from the bottom of the mould, the correct quantity of water required in the cement may be ascertained in this manner. DIRECTIONS FOR NEEDLE WITH DASHPOT. Fill dashpot with clean thin lubricating oil, it will then be ready for use, raise needle and insert pin in hole of spindle at top of stand, place filled mould on stand, raise plunger of dashpot to under part of needle head, remove pin, and needle will then travel gradually on to cement to be tested, repeat operation until test is completed. £0 12 6 £1 15 £2 10 CROSS STREET • HATTCTNT GARDEN, E-C- =3S«i^=JJJ^ BAIRD ^TATLOCK (LONDON) LTD. w 5190-5196 Cement Testing Machine, Sailer's Improved Pattern. This apparatus has now been improved and revised so as to meet the requirements ot the British Standard Specification for Cement Testing, and it will be found as perfect a machine as can be devised for the purpose. It also has been increased in strength, and the bucket, shot-run and scales made suitable for weights up to 1,200 Ibs., as owing to the recent great improvements in the manufacture of cement, it is now no unusual thing to find neat tensile tests going 900 to 1,000 Ibs. on the square inch at seven days, and of course still more than that at longer dates. The shape of the clips is in accordance with Standard requirements, and these are sufficiently massive to require no cross stays. As the speed of the shot feed is now standardised, a can for hand feed is not supplied. The speed of the shot can be adjusted to 450 or 500 Ibs. per minute. With the former speed, as the bucket weighs 50 Ibs., it makes up a total load of 500 Ibs. on the briquette in the first minute. It is better to use this speed with a sand briquette, but if the briquette is neat and the test is likely to be considerably over 500 Ibs., it had better be set to the speed at the 500 Ibs. mark. The apparatus consists of a japanned cast-iron column, carrying a pair of compound levers, having a combined leverage of 50 to i. The levers are fitted with tempered steel knife edges, which rest on polished concave bearings, also of tempered steel, thus obtaining a very sensitive balance. A sliding balance weight for the purpose of setting the levers in equilibrium, is fitted to the upper lever. The upper clamp, to receive the cement briquette, is sus- pended from a knife edge on the lower lever ; the lower clamp is attached to the base of the column, and is adjustable by means of a screw and a small hand wheel. The supply of shot to the bucket is automatically cut off at the moment the briquette breaks. To use the machine, set the levers " floating " by means of the sliding balance weight w. Once set tightly this need not be touched. If, however, it is desired to start the load from zero, this weight can be adjusted to balance the weight of the can by running it out to the end of the lever. In that case either 50 Ibs. must be deducted from the scale when weighing the shot and can, or to save this calculation the pointer of the balance can be adjusted by the screw for that purpose so as to stand at zero with the weight of the can, and in that case the pointer will give the weight of shot only. The briquette is next removed from its tank, wiped with a cloth and placed in the clamps, centrally and flush with the sides. Hang the bucket on the bridle (B), and screw up the hand wheel until the top side of the lever from which the shot can is suspended is about half an inch from the top of the guide at c. This then allows ample downward movement, if the clips slide up the briquette as the load increases, and prevents the lever touching the bottom of the guide at (D) before rupture and avoids the necessity of stopping the machine to screw up the wheel (E) again. As soon as all is ready and all the knife edges are seen to rest square in their bearings, depress the handle (H) to the first notch. If starting from zero the shot should be adjusted to run at the 500 Ibs. per minute. As soon as the briquette breaks, the bucket falls on to the rubber pad and depresses the lever (F), by which the shutter (s) is released, and so cuts off the supply of shot. All shot must be the same size — No. 6 by preference. The bucket is then removed and placed on the spring balance, by which the breaking load is at once indicated without calculation. If by any chance the shot should hang up from any cause, the container should be tapped. The machine is tested to extreme accuracy by dead weight before leaving the works. The apparatus will test with equal correctness any load from J Ib. up to 1,200. After use the machine should be at once rubbed down with a dry soft cloth and put under cover. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 51901 Double Lever Machine 5191* Shot Run 5192T Spring Balance . . 5193' Two Buckets (5/-, 3/6) 5194T Brass Moulds . . 5195r Can .. 5196T Ebonised Table . . 51971 Frame (only) of Glass Case 5198T Sieves— 20 25 30 6/- 7/- 8/- 5199T Receiver and cover to sieves 40 Polished for gun-metal fittings 1,000 Ib. tests. Steel fittings, for 1,200 Ib. tests, £ s. d. 11 10 0 best N.P. fittings. £ s. d. 15 0 0 . . 250 250 1 6 6 1 10 0 086 086 50 91- £15 10 0 £19 3 6 each, 10/- ; per doz. £5 10 0 ..£036 £3 15 0 . . 40/- ; if fitted with glass £2 15 0 60 10/- 75 10/- 80 ll/- 120 mesh. 12/6 each. £076 5201 Apparatus for making, automatically, briquettes of cement, so as to ensure the same conditions for all tests. 5200T Price, with one hammer and mould, i sq. in. section 520 1T Price, with two hammers and moulds, i sq. in. section (as illustrated) ACCESSORIES FOR ABOVE. 5207T Iron moulds, i sq. in. section . . . . . . . . . . . . each 5208T Complete set for moulding blocks of 7 centimetres side 5209T Iron moulds of 7 centimetres side . . £18 10 0 £25 0 0 £0 £2 2 £0 18 9 6 0 0 CROSS STREET • HATTOTST GARDETST, E-C BAIRD &TATLOCKL (LONDON) LTD. 5210 5212-5213 £2 2 5210 Calcimeter, Scheibler's, for the quantitative estimation of carbonate of lime, on stand complete DESCRIPTION OF SCHEIBLER'S CALCIMETER. The carbon dioxide in a carbonate may be estimated by liberating the gas by means ol an acid, and then measuring the volume of the gas. From this the weight of the carbon dioxide can be calculated , and consequently the weight of the carbonate itself, provided it is of known and definite composition. Scheibler's apparatus was originally designed for estimating the amount of calcium carbonate present in the bone black used in sugar refining, and has the advantage of being rapid and simple in use. Description of the apparatus. — The apparatus consists of (i) a vessel in which the weighed quantity of carbonate is decomposed, and containing a glass or guttapercha tube of about 12 cubic centimetres capacity in which the acid required for the decomposition is placed. The vessel is closed by a sound perforated rubber cork, into which a short bent glass tube is fitted. This is connected by means of rubber tubing with the centre vessel (2), from which the gas displaces air into the measuring apparatus. The vessel is closed by a cork with three perforations. Through one a bent tube passes connecting the first vessel, into another is fitted a long vertical tube connecting the centre vessel with the measuring apparatus, and into a third is fitted a short piece of glass tubing terminating in a piece of rubber tubing, closed by a spring or screw clamp. This serves to connect the apparatus with the atmosphere at will. The use of the balloon shown in the sketch may be dispensed with. The measuring apparatus consists of two tubes firmly fastened to an upright board. These tubes are connected together below, and the left-hand tube is connected with a Woulff's bottle containing water and employed for adjusting the water-levels in the measuring tubes. The right-hand tube has a capacity of 150 cubic centimetres, and is accurately graduated in half cubic centimetres. After fitting up the apparatus it should be proved to be air-tight by adjusting the water-level in the graduated tube at a much higher level than that of the other tube, and allowing the apparatus to stand for fifteen minutes. 52 11T Tubes, guttapercha, 3 by f in., for use with above .. .. .. .. each £016 5212 Hall and Russell's Apparatus, for determining small quantities of carbonates — Without Stand . . . . . . . . . . . . . . . . £0 15 0 5213 Hall and Russell's Apparatus, for determining small quantities of carbonates — With Stand, copper bath, etc. (See Journal of Chemical Society, No. cccclxx., January, 1902, p. 83.) £1 15 0 (CHEMICAL AND SCIENTIFIC" APPARATUS AND PURE CHEMICALS- 943 BAIRD &TATLOCK (LONDON) LTD. 5214 52141 Clarke's Calcitneter, for testing cement, slurry, limestone, etc. Price, as illustrated, with special tables for pressure and temperature corrections and absorption DESCRIPTION. The essential points of this calcimeter are accuracy and celerity, and it therefore supplies a long-felt want in the cement trade. The instrument consists of a large glass vessel of water G. B is a glass cylinder connected to a rubber ball full of water F, and containing another graduated glass tube A. It will be thus seen that by compressing F by means of screw-press H that water will rise in B and A. j is a glass bottle in which the gas is generated ; the gas evolved passes down through the glass coil DD and then into the graduated tube A. c is a burette containing HC1 of exactly the same temperature as the water contained in jar G. METHOD OF WORKING. The temperature of the water contained in G and the atmospheric pressure being known, the weight of slurry as indicated by the Table supplied is placed in the bottle j with tube containing 10 c.c. of HC1 (Sp. Gr. 1.112) ; after corking bottle on to tube L the whole lot is immersed into water in G, being supported by wire cage M. The stopcock N is then opened, and the water in B and A is then raised to zero mark on tube A by means of compressing ball F by means of screw-press H. The columns of water adjusted, the cock N is closed and the bottle taken from water. Allow acid in K to come into contact with slurry, releasing ball F at the same time with left hand. The gas evolved displaces the water in A, and care should be taken that ball F is released just fast enough to allow the levels of water in A and B to get lowered at the same time, or else the water will be found to overflow in tube B. When the action is complete the bottle is shaken in a circular motion for about thirty seconds to remove the last traces of gas and then placed in cage M to cool for two minutes. The levels in both tubes are then adjusted till they are equal, and the reading on tube A taken. This is then corrected for absorption, per Absorption Table supplied, and the result obtained. The large jar of water affords a constant temperature throughout the whole operation, and it is therefore of great advantage in assuring accurate results. Each Calcimeter is supplied with Table to give the weight of substance to be examined according to the atmospheric pressure and temperature under which the instrument is working, and Absorption Table which is calculated to give the amount of CO., absorbed and to make an allowance for any inaccuracy in the graduated gas-measuring tube. £5 15 0 14 • CROSS STREET • HATTOTST GARDETST, E-C 944 BAIR.D &TATLOCK (LONDON) LTD. 5215 5216 5217 5219 5215 Graduated Flask, for testing the specific gravity of hydraulic cements, as devised by Messrs. Stanger & Blount . . . . . . . . . . . . ..£020 (See Journal of Society of Chemical Industry, No. 5, vol. xiii., p. 455.) 5216 Graduated Flask, modified form, designed by Mr. A. D. Leipper . . . . . . £026 5217 Mann's Cement Testing Apparatus, burette, flask and case, with holder and counterpoise £110 5218 Schumann's Cement Testing Apparatus . . ..£046 5219 Schumann's Cement Testing Apparatus, improved form . . ..£076 5220 5221 5220 Le Chatelier Gauge, for testing cement (standard pattern) . . each, 2/- ; per doz. £130 5221s Bath, copper, to hold I doz. Le Chatelier moulds, Fig. No. 5220, with loose holder and iron stand • • • • • • • . £200 (CHEMICAL, AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIR.D &TATLOCK: (LONDON) LTD. 5222 Jackson's Apparatus, for the Photometric Determination of Sulphates in Cement 5223 Extra Tubes, marked to 240 millimetres, for above . . . . . . . . each 5224 Extra Standard Candles, for above . . . . . . . . . . „ Extract from " Portland Cement : Its Composition, Testing, and Analysis," by RICHARD K. MEADE. Jackson has devised a rapid photometric method for determining sulphuric acid, which is very convenient for checking this constituent in a large number of samples. The apparatus used in this method is shown in figure. Above is a glass tube, closed at the bottom, and graduated in millimetres depth. The brass holder for this tube is open at the bottom, so that the glass tube rests on a narrow ring at this point. The candle below is so adjusted by means of a spring that the top edge is always just three inches below the bottom of the glass tube. The English Standard Candle is preferred, but a common candle of the same size may be used. This candle must always be properly trimmed, and the determination be made rapidly so as not to heat the liquid to any extent. The most accurate work is obtained in the dark room, and the candle should be so placed as not to be subjected to a draught of air. Care should be taken to keep the bottom of the tube clean, both inside and out, so as not to cut out any of the light. To determine the sulphate in a cement, weigh out one gram, correct to centigrams, and rub up thoroughly with a glass rod in a small porcelain dish or casserole, with two cubic centimetres of strong hydrochloric acid. Add about ten cubic centimetres of water, and heat to boiling. Filter, and wash with a small amount of hot water, into a 100 c.c. graduated Nessler jar, and fill with cold water nearly to the 100 c.c. mark. If necessary, suction may be employed in filtering, but usually a folded rib filter will do. Now add two grams of solid barium chloride crystals, and make up to the 100 c.c. mark with cold distilled water. Pour back and forth from the tube to a beaker until all of the barium chloride is dissolved. The solution is now ready for examination. The candle is trimmed and lighted ; the solution is poured back and forth to get a thorough mixture of the precipitate of barium sulphate ; and the glass tube is placed in position in the holder. The liquid containing the precipitate is now poured into the graduated tube until the sight of the image of the flame of the candle is just visible. Then pour in a few drops at a time until it just disappears from view. The height to which this solution stands in the tube (reading the bottom of the meniscus) is then taken, and from this reading the percentage of sulphates present in the cement may be read directly from the following Table : — FOR THE DETERMINATION OF SULPHATE IN CEMENT. £140 £050 £008 Depth cm. Per cent. S03. Depth cm. Per cent. SO3. Depth cm. Per cent. S03. Depth cm. Per cent. SO,. .0 5-2 4.0 M 7.0 0.8 10.0 0.6 .1 4.8 4-1 1-4 7-i 0.8 10.2 0.6 .2 4-4 4-2 1-3 7-2 0.8 10.4 0.6 • 3 4-1 4-3 1-3 7-3 0.8 10.6 o-5 •4 3-8 4-4 1-3 7-4 0.8 10.8 0-5 •5 3-6 4-5 1-3 7-5 0.8 II. 0 0-5 .6 3-4 4.6 1.2 7.6 0.8 II. 2 o.5 • 7 3-2 4-7 1.2 7-7 0.7 11.4 0-5 .8 3-o 4.8 1.2 7-8 0.7 n.6 0.5 1-9 2.9 4-9 1.2 7-9 0.7 n.8 0.5 2.0 2-7 5-0 I.I 8.0 0.7 12. 0 0-5 2.1 2.6 5-1 I.I 8.1 0.7 12.2 o.5 2.2 2-5 5-2 I.I 8.2 0.7 12.4 o.5 2-3 2-4 5-3 I.I 8.3 0.7 12.6 o-5 2.4 2.3 5-4 1.0 8.4 0.7 12.8 0.4 2-5 2.2 5-5 1.0 8.5 0.7 13.0 0.4 2.6 2.1 5-6 1.0 8.6 0.7 13.5 04 2.7 2.1 5-7 I.O 8-7 0.7 14.0 04 2.8 2.0 5-8 1.0 8.8 0.6 14.5 0.4 2.9 1-9 5-9 I.O 8.9 0.6 15.0 0.4 3-° 1-9 6.0 0.9 9.0 0.6 15.5 0.4 3-i 1.8 6.1 0.9 9-1 0.6 , 16.0 0.4 3-2 1-7 6.2 0.9 9-2 0.6 16.5 0.4 3-3 1-7 6.3 0.9 9-3 0.6 17.0 o-3 3-4 1.6 6.4 0.9 9-4 0.6 17-5 o-3 3-5 1.6 6.5 0.9 9-5 0.6 18.0 o-3 3-6 1.6 6.6 0.9 9.6 0.6 18.5 0-3 3-7 1-5 .6.7 0.8 9-7 0.6 19.0 o-3 3-8 1.5 6.8 0.8 9.8 0.6 I9o °-3 3-9 M 6.9 0.8 9-9 0.6 20. o o-3 5222 5225 Candles, standard each, 8d. ; per Ib. £040: CROSS STREET • HATTOX GARDEN, E-C- BAIRD &TATLOCK (LOM)ON) LTD. SECTION No. 14. APPARATUS AS USED IN EXPERIMENTAL TESTING OF LEATHER TANNING AND DYEING BY DR. PARKER AND DR. LAMB OF THE LEATHERSELLERS' COLLEGE. 5226 (shut) 5226 (open) 5226s Apparatus for drying tanned bark, consisting of pyramidical-shaped bath of copper with constant level, double walled, with copper condenser and constant level arrangement from condenser to bath, on stands, with set of burners . . . . . . £16 16 0 5227 r Hide Powder for tanning estimation, Dr. Parker's Standard per oz., 1/6 ; per Ib. £0 18 0 5228 5228s Shaker, to take twelve 20-oz. wide-mouthed bottles, each division felt lined, with pulley for driving by power or hand, without bottles . . . . ..£450 | CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 5229-5232 5229' Vacuum Drying Oven, as adopted by the International Society of Leather Trades Chemists consisting of an inner chamber 2oi in. long and n| in. diameter with a i-m. water jacket all round The oven is fitted with a heavy lid to swing back, a 4-in. ball condenser, water level, and vacuum gauge, with tubulures for thermometers, two movable shelves inside 5230s Vacuum Drying Oven as above, covered with asbestos 5231s Vacuum Drying Oven, same as No. 5229, but 12 in. long and 7 in. diameter . . 5232s Vacuum Drying Oven as above, covered with asbestos £19 19 0 £21 4 0 £15 10 0 £16 10 0 5233-5235 5233 Barkometers, paper scale 5234 Barkometers, ivory scale 5235 Barkometers, best quality, open scale 10 in. long each £0 £0 £0 4 0 4 6 5 0 Any other special Hydrometer suitable for testing chrome solutions, etc., can be made to order. CROSS STREET • HATTO^T GARDETST, E-C 948 BAIRD &TATLOCK (LONDON) LTD.! 5236 5238 5236* Shaker, large pattern carrying six jars 12 by 6 in. diameter, with wooden caps, rubber pad, with lower shelf for resting jars when not in use. The shaker should revolve at about 30 r.p.m. Price without jars 5237s Jars for above, 6 in. diameter by 12 in. long, stout glass . . each 5238s Metal Shaker in the form of a wheel, arranged to screw to bench, capable of taking six bottle Wlde"mouthed bottles- The shaker is fitted with fast-and-loose pulley, without 5239s Metal Shaker, similar to the above, but arranged to take twelve bottles with pulley wheel in centre and bottles on either side, without bottles . £5 £0 £7 10 0 £12 10 0 5240 5240' Baths for dyeing samples of leather 18 in. long by 5 in. wide by 6 in. deep, with perforated false bottom. The interior of the bath is arranged to carry six cells. Price complete with six cells £2 15 0 949 BAIRD &TATLOCK (LONDON) LTD. SECTION No. 15. APPARATUS FOR PAPER TESTING. 5241 5243 5241s Autoclave as figured, for experiments in converting wood and bamboo into paper pulp, to work at 8 atmospheres pressure. Copper boiler, lead lined, 17 in. deep by 13^ in. diameter Price complete with gas burner . . . . . . . . . . £28 0 0 5242s Autoclave as above, with oil burner . . . . . . . . . . . . £28 10 0 (See No. 325 for full description.) 5243T Leunig's Testing and Registering Apparatus, for estimating the resistance to creasing and crumpling of paper by the insertion of a sample strip as marked PP. z is the self- registering dial ; the cylinder F contains the springs, and can be regulated according to the strength of paper to be tested . . . . . . . . . . . . £30 0 0 CROSS STREET • HATTOTST GARDE1ST, E-C 950 BAIRD &TATLOCK (LOM)ON) LTD. 5244 5245 5244T Schopper's Apparatus, for estimating the percentage of moisture in paper pulp. Price without burner .. .. .. .. .. .. .. .. £20 15 0 5245T Leunig's Patent Self-Registering Apparatus, for testing the strength of paper and other fibrous materials, and indicating both strength and elongation under the tensile and breaking strain in one operation. Price with cutting machine . . . . . . £23 0 0 5246 ^.jc^rvT^K- 5247 5246T Leunig's Paper Scales, showing correctly at a glance, by weighing a single sheet, the weight of a ream of paper of any size, containing either 480, 500, or 516 sheets, £ to 80 Ibs. 5247T Leunig's Micrometer, for registering automatically the thickness of cardboard or paper, from i to 2T)W in. ; diameter of dial, 5j in. . . . . . . . . ..£4 £2 10 0 951 BAIRD &TATLOCK (LONDON) LTD. SECTION No. 16. Apparatus for Physico-Chemical Experiments. 5248 5249 5248r 5250 Model I. Price of the instrument Capillary Electrometer, after Ostwald Luther. complete, with capillary tube as figured Consists of large pattern microscope, easily adjustable and mounted on tripod stand. The microscope is fitted with a micrometer eyepiece reading to o.i millimetre. The capillary tube is held in a clamp and easily adjusted to the correct height The stand is also fitted with well insulated terminals for connecting current to the capillary tube. 52491 Light Arrangement for use with Model I. Price for use with 2-volt accumulator Consisting of heavy base with adjustable pillar, terminals and switch. The lamp is mounted in a metal frame and protected by a milk glass plate, adapted for use on a 2-volt circuit. 5250T Capillary Electrometer, after Ostwald Luther. Model No. II. Price complete, with lamp and switch as figured, and one exhausted capillary tube This instrument is very similar to Model I., except that the whole apparatus can be easily inclined to an angle of 45°. The capillary is held quite free from the rest of the apparatus, and is easily adjusted to the required height. An Osram lamp is fixed on an adjustable arm. 525 1T Capillary Electrometer, after Ostwald Luther. Model No. III. The complete apparatus, as figured, with one capillary tube This instrument is very similar to Model II., but is so arranged that by means of a fine adjustment the capillary can always be brought in a vertical position in front of the microscope so that the microscope can be turned in its vertical axis into the middle of the observation field. £0 12 0 £550 £6 10 0 CROSS STREET • HATTOW GARDETST, E-C 952 BA1RD &.TATLOCK (LONDON) LTD. SecTioN XVI. FOR PHYSICO CHEMICAL EXPERIMENTS Conductivity Cells Electrometers Electrical Measuring Instruments Stirrers, etc. Stills for Conductivity Experiments Thermostats Pages. 966-967 952-954 968-976 960 - 962 956-959 Special Apparatus not included in this list can be supplied to sketch. 14. CROSS STREET, HXTTON3ARDEN, EC C2x*fc - — BAIRD &WLOCK (LONDON) LTD. JL j_^ jmia^^ss^s ssgi^p^^^^^^^ ^a^Rf^/^ The following are the different Sections in out Catalogue. Those marked * are also printed separately. Pages Nos. Section No. I.* Laboratory Fittings 14-5( 2.' Bacteriological Apparatus 57-16 3. Chemical Physiology Apparatus 162-19: » « 4.* Microscopes and Microscopical Accessories 193-321 5.' Balances and Weights 321-38: 6.' Chemical Apparatus 383-81 7.* Botanical Apparatus 817-84 * * 8. Gas Analysis Apparatus 843-88 i * 9." Milk Analysis Apparatus 887-89 1 1 10. Refractometers 895-90 » > 11." Oil Analysis Apparatus 903-92 * > 12. Water Analysis Apparatus 927-93 » » 13. Cement Testing Apparatus 934-94 * » 14. Leather Testing Apparatus 947-94 * * 15. Paper Testing Apparatus 950-9^ * * 16. Physico Chemical Apparatus 952 -9/ t* 17.* Pyrometers 977 -10( » > 18.* Calorimeters 1007-10; »» 19.* Seed and Soil Analysis Apparatus 1023-10' M 20.* Spectroscopes and Polariscopes 1043-lOi * f 21. Volumetric Apparatus 1079-10! »» 22. Anatomical Models 1088-1H 1 1 23. Meteorological Apparatus 1106-11: 24. * Assay Apparatus 1125-11 -^"^. 25.* Chemicals 1187-12 /z>^ MF*" m 'i 14 BRn )SS STREET • HATTON GARDEN, *- »B E-C- KLLa *^^^"^^p^yf- *J*-*^-—*&gs> BAIRD •&. TATLOCK (LONDON) LTD. 5252 5253 5254 5255 5252T Supplementary Apparatus required for use with Leppmann's conical capillary in addi- tion to Electrometer Model III., and capable of holding acid cell and the electrometer tube A. Price complete . . . . . . . . . . . . ..£230 5253T Horizontal Capillary Electrometer, after H. Sand, as devised for the rapid electrical analytical separation of metals. Stand is inclinable by means of screw, and a milk glass scale thermometer is fitted to the glass part, and spare bulb is added for mercury and acid. Price, with lense complete . . . . . . ... . . ..£230 5254T Electrometer Tube, new form, filled with distilled mercury and pure sulphuric acid. This is exhausted and sealed. Two platinum tubes are sealed into the electrometer tube. The section of the capillary is oval . . . . . . . . ..£056 5255T Electrometer Tube, after Ostwald Luther. The filling and arrangements of this tube is similar to the preceding one. The other part is connected by means of a bulb shape tube, whereby the overflow, on account of the changing of height of the mercury, in the capillary is facilitated. On the side of the capillary, which is usually turned to the micro- scope, a cover glass is fitted so that the scale is easily read. Price as figured . . . . £060 5256 Platinum Electrodes, complete as figured. A Price . . 4/- A5256 Zinc and Copper Electrode, complete as figured B 2/6 A5256 C 3/3 each. per pair £016 (As there are many patterns of the above electrodes, we have only figured a few, but will be pleased to manufacture any other form.) ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 953 BAIRD &TATLOCK (LONDON) LTD. B5256 5257 5258 B5256T Electrometer Key, for use with the preceding electrometers, and mounted on a heavy foot 5259 The key is well insulated approximate 52571 Platinum Anode, as Fig. A 52581 Platinum Cathode, as Fig. B . . 52591 Capillary Electrometer (Ostwald's), mounted on inclinable stand with scale, complete with platinum wires. Fill electrometer as follows : pour pure dry mercury into Limb A of electrometer, also half fill the bulb of the other limb with mercury and the rest of the tube with dilute sulphuric acid (i part by volume of acid to 6 of water) £0 13 £3 5 £10 0 £0 17 6 5260 5261 5262 52601 Capillary Electrometer Tubes, after Ostwald, with platinum wire in bulb . . . . £02 526 1T Capillary Electrometer Tubes, „ „ £020 52621 Stand with H Tube, for fitting with the cadmium normal elements, complete with platinum «/irAC wires £050 CROSS STREET • HATTCTNT GARDE1ST, E-C 954 BAIRD &TATLOCK (LONDON) LTD. PARAFFIN WAX 5263 5263T Standard Cadmium or Weston Cell. The latest portable H pattern has been adopted, and gives an E.M.F. of 1.018 volts at 15° C. The temperature co-efficient is so low as to be negligible for all except research work of the highest order, being about .0035 per cent, per degree C. ; no thermometer is therefore fitted. Price of single cadmium cell in improved case . . . . . . . . . . . . . . . . £1 15 0 5264T Double Cadmium Cell, as above . . . . . . . . . . . . £2 10 0 (Certificate of the E.M.F. of any of the above can be furnished by the National Physical Laboratory at a charge of 5/- per cell.) 52651 Single Cadmium Cell, unmounted . . . . . . . . . . . . £0 15 0 5266T Stand of Five Cells, complete with H glass tubes, platinum wires, with seven plugs, so that either the whole series or any single cell can be used . . . . • • • • £1 12 0 5267 5270-5271 5267T Pair of Half Cells, with stand and cylinder as figured. Price complete, but without electrodes 5268T Glass cells only . . 52691 Stand only Glass Trough, for mercury, for easily filling tubes, etc. 5270 Diameter of top, 4 in., total height, 8J by 2 in. diameter of body 5271 „ „ s£ in., „ 7 by i£ in. each £0 15 0 £020 £056 £029 £036 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 955 BAIRD &TATLOCK (LONDON) LTD. 5272T Ostwald's Water Thermostat, copper vessel, felt covered, size 12 by 10 iti., with Lowry's gas regulator, micro burner, and stirring arrangement as illustrated . . . . £4150 5273r Thermostat Tank, height 18 in., width 12 in., depth inside 10 in. Copper ends with glass sides, mounted on stand, with burner ; the ends are felt covered . . ... each £2 15 C 14 • CROSS STREET • HATTCTNT GARDETST, E-C BAIRD &.TATLOCK (LONDON) LTD. C5275 E5275 5274T Thermostat, copper, adapted for temperatures above 100° F., with stirring arrangement, 4 clamps for carrying small flasks, adjustable bar with 6 clamps and bossheads, I nickel plated adjustable tray, clamps for thermometer and regulator, stand and burner (without constant level) Size 24 by 16 by 16 in., encased in wood frame with uralite panels, plate glass fitted on each side to a depth of 6 in., to facilitate readings being taken. The thermostat is well insulated with slag wool, and is supplied with an axle fitted with vanes for stirring and clamps for shaking flasks, etc. The axle is adjustable vertically, and is clamped to the top edge of the bath. The bath is also fitted with a rectangular bar of metal held at each end by adjustable clamps, and carrying 6 small bossheads and clamps for holding dilatometers, etc., in the liquid. 5275T Thermostat, as figured . . . . . . . . . • As above, with fittings as specified, but arranged for temperatures lower than room temperature, with cooling worm for supply of water and constant level. The fittings can also be supplied separately at the following prices : — A5275T Movable Adjustable Tray, nickel plated, as shown under No. 5274-5275 B5275T Clamp for fitting to axle for carrying small flasks . . c5275T Rectangular Bar of metal, 2 ft. long, with 2 end clamps for fixing to sides of bath, and 4 bossheads and clamps D5275T Bossheads only . . . . . . . . ' E5275T Clamps only . . 5276T Pulley and Horizontal Axle for fixing on end of bath, stirrer adjustable vertically for a distance of 30 cms. . . 52771 Stirrer and Pulley, with long arm for clamping on to edge of bath. The stirrer is metal, but the clamp is supplied to carry any of the stirrers, No. 5295 52781 Clamp and Stirrer Arm, without stirrer £13 7 6 £13 17 6 £0 17 6 £046 £0 18 6 £010 £026 £1 1 0 £0 12 6 £080 n CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 957 BAIRD &TATLOCK (LONDON) LTD. 5281 5279-5280 5282 52791 Thermostat, similar to No. 5274, but fitted with teak table round edge of bath, total length 50 by 36 in. wide, with accessories as described No. 5274 . . . . . . £16 7 6 5280T Thermostat as above, for temperatures below room temperature up to 100° C. (This is arranged by a constant flow of water, as shown in Fig. 5275) . . . . • • £16 17 6 528 1T Clamp for fixing on to edge of bath, with ring for holding cell and mercury cup for connections. Price as figured, but without cell . . . . . . . . • • £0 10 6 5282r Stand as Fig. 5282, and clamp as Fig. 5281, for use on the bench. Complete with mercury cup and cell holder £0 13 6 5283 5284 5283T Universal Holder, nickel-plated, for use in baths, Nos. 5272 and 5274, with indiarubber tubing, it will hold flasks, bottle, etc., as figured 5284T Small Double Burner for keeping baths, etc., at a low temperature each £046 £026 958 BAIRD &TATLOCK (LONDON) LTD. 5285 5285T Thermostat, new pattern, designed by Dr. Lowry to supply a rapid stream of water heated to constant temperature. This bath gives a flow of water, the temperature of which does not vary by more than a few thousandths of a degree, even when a maximum rate of 4 litres (water) per minute is maintained. The apparatus, as shown, consists of a large zinc-lined wooden box, 20 by 18 by 16 in., with a capacity of over 70 litres, stirred by means of a propeller driven by an electric motor. The large bulk of well-stirred water and the heat insulation of the wooden box and cover render the regulation of the bath temperature exceptionally easy, with the result that when the gas flame is controlled by a 4 in. spiral regulator the variations are so small that they escape detection even with a thermometer graduated in 1-100°. The heating is effected by means of a small burner placed beneath a copper plate which forms the bottom of the central well of the water bath ; the supply of gas to the burner is controlled on one hand by the bye-pass tap B, and on the other by the spiral s. The bath is provided with an adjustable overflow. In cold weather it is only necessary to allow an occa- sional drop of water to drip into the side tube of the bath to maintain the level ; but in summer the flow is diverted into the bath itself and greatly increased. Ideal conditions are reached when the air temperature is up to 20° C., the water temperature a few degrees below. The water circulation is maintained by means of an electric driven pump, which sucks the water out of the bath from a point near to the centre of the regulator, and draws it through the various jackets, and returns it to the bath. The temperature of the return flow can be read by means of a standard thermometer T, graduated in i-iooths, which dips into a tube of mercury round which the circulating water passes on its way back to the pump. The rubber bulb serves to take up a part of the thrust of the pump. It usually becomes flattened, but continues to pulsate when the flow of water exceeds I litre per hour. The pump is driven from an electro-motor through the gearing, which carries the propeller and is provided with several adjustments. The speed of the motor is controlled by a lamp resistance. When this is short circuited the pump pro- duces a maximum flow of 4 litres per minute. Under normal conditions a 180 v. 16 c.p. lamp resistance on a 200 v. circuit gives a flow of about i litre per minute, the temperature gradient with the bath at 208 and the | room at 15° C. is then 0.01° C. per jacket unless the apparatus where temperature is to be maintained constant can actually be immersed in the water bath, it is necessary. Whatever scheme is used to effect the regulation at a distance of a foot or two from the observation tube. In the apparatus described above, the temperature gradient in the leads and the jackets is reduced to a minimum by the rapid flow of water, which can be increased to any desired extent by speeding up the pump or by increasing its size. Price, complete with electro-motor, pump, etc., as figured Please state voltage of current available. £17 10 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 959 5286 (Fig. i) 5286 (Fig. 2) 5286 (Fig. 3) 5286s The Purification of Water by Continuous Fractional Distillation. By William Robert Bousfield, M.A., K.C. Patent No. 25699/01 The above apparatus is stated to produce by a process of continuous fractional distillation, a water equal la purity to that prepared by Stas for his atomic weight determinations. The still can be run continuously day and night, producing a total of some ten litres a day, which may be roughly divided into three qualities, and it has the advantage over Stas' method that the purification is effected in one operation instead of three. The best quality water has a conductivity of about X = ixio — °,a value which may be taken as typical of a thoroughly good sample of conductivity water. £5 5 960 BAIRD &. TATLOCK (LOM)ON) LTD. The apparatus consists of two parts — a still and condenser, see Fig. i. Fig. 2. — The Condenser consists of a box of sheet copper with a lid which has four openings with inclined sides. These support four test tubes cooled by circulating water. Through two of the tubes a rapid flow of water passes, and from these the best water is collected by means of funnels i and 2. Through the other tubes water passes very slowly and is used to feed the still, and serves also to condense a small quantity of water collected by the funnels. About one-third of the water distilled condenses on the surface of the copper box, and is collected from the copper tube. This is the lowest quality, and is good ordinary distilled water. The Water. — The conductivity of the best water produced depends to some extent on the conditions under which the still is used. The addition every two or three days of a little alkali to the still in order to retain carbon dioxide was found to be an advantage, or in the alternative, the addition of potassium hydrogen sulphate to keep back ammonia and basic impurities. Under these conditions the normal product of the coolest tube is m -in mho- water " (X = i x 10 — •), and this can be produced in any desired quantity. By storing this water in a Ian,'<' bottle in contact with air, freed from carbon dioxide by means of lime, its conductivity can be reduced to and can be further improved by boiling. No advantage is derived from condensing the purified water on platinum instead of glass tubes, provided that soft glass is not used. A very great improvement results, however, if the purified water is boiled for a few minutes in a platinum bottle. In one instance a sample of water that had an initial conductivity of 0.84 x 10 — • at 18° was reduced by boiling for two minutes to 0.48x10 — ', representing an exceptionally high degree of purification. The still can also be used for the preparation of ammonia free water and copper free water. Fig. 3. — A specially designed still to prevent spray being carried over with the steam. The copper cylinder is furnished with a branch pipe A. B is the opening into which the water is fed continuonsly, the excess escaping at F. The spray, which is driven against the baffle-plates, runs down the sides of the funnel D and back into the water below. An external covering EE serves to economise the heat of the burner. 0 OF 0 5287 (Section) 5287 5287s Bousfield's Pan Still (Patent Application No. 14223, 1912) This still produces water of a conductivity of less than i gemmho practically free from ammonia, by continuous fractional distillation from ordinary " tap-water." (See Journal Chemical Society, August, 1912.) It may be run continuously day and night, and with a yj inch pan will yield daily about 20 litres of " conductivity water " and 10 litres of ordinary good distilled water. One of these stills will thus supply all the ordinary requirements of a laboratory, and the bulk of the product is suitable for conductivity and analytical work of a high degree of accuracy without additional expense. The open pan construction is extremely convenient, as it enables the apparatus to be readily cleansed from scale or other deposit which collects in the pan. But the part which the open pan plays in purification is more essential. Feed-water is supplied in the open annulus between the pan and the cylinder. It has gradually tc make its way downwards until it passes underneath the bottom of the open cylinder into the interior. During this passage from the exterior to the interior, the organic impurity of higher boiling point, which e ordinary water, is largely decomposed before the liquid reaches the interior of the cylinder, so that the ammonia thus liberated, and also the carbon dioxide and dissolved air contained in the water, are boiled off and escap< into the open air instead of passing through the still. This feature materially contributes to the improved results which this still gives 961 £450 BAIRD &.TATLOCK (LONDON) LTD. DESCRIPTION OF THE STILL. (See Diagram.) The water to be distilled is boiled in an open pan, A, furnished with an overflow pipe, B, at the side. The main condenser consists of a double cylinder of block tin ending above in a dome, which is shown in section by . the lines c, D, E. These cylinders form a pocket, D, at their lower end, in which water condenses, and from which it is led away by the pipe G. Round the outer surface of the main condenser, at a short distance above the pocket, there is provided a series of holes, F, through which the vapour which is not condensed in the pocket passes into an annular chamber, H. This is connected at one side to an escape pipe K, which serves as an auxiliary condenser, being surrounded with a water circulation jacket, L. The main condenser is jointed by means of a water-seated joint to a copper cylinder, M, which is open at the bottom, and stands in the open pan, A. The spray arrester, N, consists of a short cylinder furnished with suitable slits, v, through which the steam issues tangentially, and within a cap, N, which deflects the steam downwards. The cyclonic action set up by the tangential flow causes spray to be deposited and to run back into the pan. The main condenser is jacketed by an outer cylinder, p, which is covered with a loose lid, Q, in order to arrest the escape of steam. Condensing water is supplied by a funnel, R. The quantity required is very small (60 to 90 c.c. per minute, according to the temperature of the supply), and it escapes by an overflow, s, and is delivered by a pipe, T, as feed-water into the pan, A. In operation the flow of condensing water into the funnel, R, is so regulated that the temperature of the main condenser varies from 100° at the top to about 95° at the bottom. Under these conditions, if the water in the pan is vigorously boiled with a suitable ring-burner supplied with gas at 2 inches water-pressure, about two-thirds of the vapour is condensed in the main condenser. The surplus one-third passes through the holes F into the annular ring H, and is condensed at K. The flow of gas and water require careful adjustment, which is soon learned by experience. If, for instance, with full gas supply, excess of condensing water is supplied through R so that the temperature at the bottom of the main condenser falls below 90°, the whole of the vapour will be condensed in the main condenser, and there •rill be little or no fractionation. If, on the other hand, too little condensing water is supplied, there will be little condensation in the main condenser, and the bulk of the water will be condensed in K. With a steady gas-pressure and water-pressure, however, the still maybe left to itself through the night without any interference. The water from the condenser L should not be used to feed the funnel R, as the temperature equilibrium then becomes unstable. 5288* Hartley s Still, for the preparation of pure distilled water for conductivity experiments, agned by Messrs. Hartley, Campbell, & Poole, Balliol College, Oxford. The still consists of copper vessel A, 10 litres capacity, lined inside with pure tin. Condenser tin throughout, with glass condensing vessel T. Price of still complete, as ngurea, with burner and stand (See Journal Chemical Society, 1908, p. 428.) 5288 £3 3 0 BAIRD & TATLOCK (LONDON) LTD. 5290 5289 5289 Retort Stand on heavy base, 12 by 6 in., with twin steel rods, 36 in. high by $ in. diameter, connected together by a sliding clamp 5290 Clamp consisting of two bossheads joined together by means of a steel rod, 3 in. long £0 £0 5291 529 11 Set of Driving Wheels, complete with motor and plug arranged on board for producing various speeds for shaking machines, stirrers, etc. ; the diameters are i J, 3, 5, 7, 10 in. ; the motor is fixed to sliding block with clamping screws so that the driving belt can be easily fitted to any diameter of pulley A52911 Set of Wheels, as above, without motor, on stand for wheels only When ordering please state voltage of current. £5 10 0 £330 _ _ BAIRD &TATLOCK (LONDON) LTD. 5292 5293 5292T Stirring Apparatus, new pattern, designed by Messrs. Dupre & Sons . . Consists of two glass stirrers with vanes rotating in opposite directions with pulley wheels mounted on double upright stand 2 ft. high, with movable cross arm and damp for carrying stirrer at any required height, glass stirrers are supplied 10 in. long, but can be had any length required, and are easily removed The mot c of the stirrers in opposite directions produce a thorough mixing of the solution, and prevent the .circular rotation produced with the ordinary stirrer. The cross arm on the upright rods render them very steady. ,at the same time carrying the stirrer to required position. 52931 Stirring Apparatus, new pattern, as above, without stand but with rod arrd bosshead for attaching to any steady upright, not over \ in. diam. . . £2 15 0 £1 18 0 ^=^ 5295s Stirrers, glass, length about 12 in., fitted with aluminium pulley wheel, metal connecting tube, and indiarubber cork. A B C D E F G Price 3/6 2/6 3/6 3/6 3/6 3/6 3/- each. Pulley wheel with tube only, 2/6 each. CROSS STREET • HATTON GARDEN, E-C BAIRD &TATLOCK (LONDON) LTD. 5296 5297 5296- Pyknometer as used by H. Hartley and W. H. Barrett, extremely light ; each pyknometer is supplied with a counterpoise. (For full particulars see Trans. Chem Soc p 1071 1911, vol. 99) .. . 'each £026 5297 Pyknometer, new design, by William Robert Bousfield, M.A., K.C. Total capacity 30 80 100 150 Price •• 3/6 4/- 5/- 6/6 250 7/6 This pyknometer consists of two tubes A and B, connected as shown by a short tube c and by a handle r> ™ S H SUSPrd the.aPParatus at a suitable height in a thermostat7 The tubes A and B L conceal at ™' ' bes E and F o£ fine bore to conical cups G and H, which can be closed by 350 C.C. 8/6 each. of ^S fnr60^^ filter PUm,P °r °ther exhaustePry Trying operations completed" Jiquid into one .of the cups, and sucking air from the other. nlefp P?thlyifil',ed Wfth Hquid Until the temPerature adjustment is attained. The'excess ut, and the last portions removed by a piece of filter paper screwed to a fine point. The ' 2. The apparatus acts as a very sensitive thermometer when the level of the liquid has been adjusted. It can then be left a minute or two longer ,n the thermostat, and an observation of the level with a magnify- !£,!?!„ ' "dl!!f S °n!! Whether the temperature of the thermostat has been attained. i of filling tends to extract some of the air dissolved in the liquid Any air bubbles that are present at any stage can be detached ' Pyknometer, and can be readily expelled by sucking some of the liquid : or the other. ..ght, is so strong that it will bear some amount of rough handling, and, in breakage" W'P y wlth.some vl?our- a£ter taking from the thermostat, without risk of As an example of the degree of accuracy of which the apparatus is capable in ordinarv use there is annpnrlpd th:iotfcnos^^^ cubic centimetres °- ' g °Ut 25° CUbiC centi™tres and of Pyknometer No. 2 about 350 Densities of Normal Nitric Acid. Densities. Difference. 5 -5 -7 "ssure6 WThP^S ^ ^ ^^ -°n^ ordinfry Precautions as to observation" of temperature and barometric decimals'. maximum, difference in the results from the two pyknometers is less than± i in the fifth place of Temperature. Pyknometer No. i. Pyknometer No. 2. 4° 1.035801 1.035796 11 1 -034336 1.034341 18° •9C° I-032435 1.032442 tEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK. (LONDON) LTD. 5298 5299 5300 5302 5303 5298s Flasks, Resistance glass, for water conductivity experiments, wide necks, fitted with ground over caps as shown, 1000 cubic centimetre capacity. (See Trans. Chem. Soc., 1908, vol. 93, p. 539.) 5299* Conductivity Cells of Borosilicate glass with ground over cap as shown. (See Trans. Chem. Soc., 1908, vol. 93, p. 539.) Price, with platinum electrodes 5300T Electrolytic Cell with vulcanite cap, complete with platinum electrodes 53011 „ „ ., I.R. cap 53021 Electrolytic Cell with vulcanite cap, as figured with platinum electrodes 53031 Kohlrausch's Cell with thermometer fixed in glass stopper, with platinum electrodes . . £020 £2 5 £3 0 £2 19 £1 12 £3 5 0 0 0 0 0 5304 5305 5308 5304T Resistance Cell with adjustable platinum electrodes 5305T Kohlrausch's Cell stoppered, with platinum electrodes, tubes graduated 5306T Glass Cells, only for Nos. 5300 and 5302 . . 5307T Stand with ring, etc., as figured under Nos. 5281 and 5282 . . 5308T Kohlrausch's Cell, with large spiral platinum electrodes 53091 Kohlrausch's Cell, with plat num electrodes ; 5 different sized glass cells for different resistances £2 2 BAIRD &TATLOCK: (LONDON) LTD. 5310 5311-5312 5313 5314 \* 5310T Resistance Cell, with platinum electrodes and 3 glass cells, the smallest holding i cubic centimetre . . . . . . . . . . . . . . . . . £1 15 0 531 1T Large Resistance Cell, with limbs divided into J divisions .. .. .. .. £1 18 0 5312T „ „ „ „ i £1 13 0 53131 Dip Electrode, for bad conductors . . . . . . . . . . ..£180 5314T Dip Electrode, for good conductors .. .. .. .. .. £100 r 5315 5316 5317 5315T Pipette Electrode, for measuring . . 5316T Dilatometer, with 5 bulbs and scale between each, divided into tenths 5317T Thermometer Magnifiers, to fit thermometers J in. diameter (Any other form of Resistance Cells can be made to order.) each £220 £0 12 6 £050 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 967 BAIRD &TATLOCK (LONDON) LTD. Electrical Measuring Instruments Used for Physico -Chemical Research Work. 5318-5320 5318s Wheatstone Bridge Boxes (Portable Form, with hinged movable cover; Battery and Galvanometer Keys), in mahogany case with polished vulcanite top, solid brass blocks with plugs ground to fit, and interchangeable. Coils, i — 50 ohms. Total resistance no ohms. Number of proportional coils 2 pairs 5319s Wheatstone Bridge Boxes as above. Coils, i — 500 ohms. Total resistance 1,100 ohms. Number of proportioned coils 3 pairs 5320s Wheatstone Bridge Boxes as above. Coils, i — 5,000 ohms. Total resistance ii.no ohms. Number of proportioned coils 3 pairs Accuracy of all Coils to within i part in 1,000. 5321-5324 5321s Series Resistance Boxes in polished mahogany cases with polished ebonite cover. The plugs are fitted with vulcanite heads, and are carefully ground to fit the brass blocks which are well undercut for clearance ; all plugs are interchangeable in each box. The coils are wound on metal bobbins, and are carefully insulated. With coils, i — 50 ohms. Total resistance no ohms 5322s Resistance Box as above, with coils, .1—50 ohms. Total resistance in ohms. 5323s Resistance Box as above 5324s Resistance Box as above 1—500 i — 5,000 „ Accuracy 1 1,110. 11,110 £600 £7 10 0 £8 10 0 £3 10 £5 0 £5 0 £6 10 in 500. BAIR.D &.TATLOCK (LONDON) LTD. 5325 5325s Resistance Box (Post Office Form) Wheatstone Bridge, comprising set of 17 coils each .1, i, 2, 2, 5, 10, 10, 20, 50, 100, 100, 200, 500, i,ooo, i.ooo, 2,000, and 5,000 ohms, total 9,900.1 ohms wound with D.S.C. Manganin wire (non-inductively). The blocks are of heavy brass, 3.5 centimetres long by 19 millimetres wide, and 16 millimetres thick, each brass block has an extra plug hole in centre to fit plug connector terminals, two of which are supplied with box, and are interchangeable with plugs. There are three pairs of proportional coils, two of i, two of 10, and two of 100 ohms. The plugs are all brass with cross pin head, and are accurately fitted into blocks. Two depression keys are fitted and lines marked on top of vulcanite to indicate paths of the wires beneath. Com- plete in mahogany case with hinged cover, adjusted to an accuracy of 0.1 per cent. £10 15 0 5326 5326s Kohlrausch Wheel Bridge. In order to obtain the advantage of a long branch wire with- out the inconvenient extension otherwise necessary, the wire in this instrument is wound with 10 turns, about 24 ohms maximum (permanent load about 6 volts), on a slate drum divided into 100 parts on a plated ring mounted on the edge. The moving contact is formed by a small traversing roller, this is also used for counting the turns in circuit, and the permanent connections are made by brush contacts of twenty wires 5327s Kohlrausch Wheel Bridge as above, but supplied with comparative resistances of 1, 10, 100, 1,000 ohms. £5 17 6 £800 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 969 Ki«fc . BAIRD &TATLOCK (LONDON) LTD. 5328-5339 Dial Rheostat, new pattern, for accurate measurements, fitted with trough for increasing the ampere capacity by insulating the coils with oil, which gives the box a greater carrying capacity. In this form the dials can be rotated in either direction, and the ends of the brushes are so bent that they do not lie tangent to the circle in which they travel, and only cause a minimum amount of wear on the blocks. No. of Dial. Range of Resistance. I .1 — I ohm I I — IO „ I 10 — 100 „ 1 100 — 1,000 „ 2 .1 — II 2 I — 110 „ 2 IO — 1,110 ,, 3 .1— in „ 3 1—1,110 „ 4 10 by .1, 10 by i, 10 by 10, 10 by 100, i,in ohms 5338s Dial Rheostat, as 5237, with five ratio coils, i, 10, 100, 100, 1,000 5339s Dial Rheostat, as 5236, with four ratio coils, i, 10, 100, 1,000 5328s Dial Rheostat 5329s Dial Rheostat 5330s Dial Rheostat 5331s Dial Rheostat 5332s Dial Rheostat 5333s Dial Rheostat 5334s Dial Rheostat 5335s Dial Rheostat 5336s Dial Rheostat 5337s Dial Rheostat Price: Without Oil Trough. With Oil Trough £4 0 0 £4 12 6 £3 16 0 £4 9 0 £3 17 6 £4 10 6 £4 0 0 £4 15 0 £7 7 6 £8 2 6 £7 2 6 £7 17 6 £7 5 0 £8 0 0 £10 5 0 £11 0 0 £10 0 0 £10 15 0 £12 10 0 £13 5 0 £16 10 0 £17 10 0 £12 15 0 £13 15 0 5340-5341 5340s Slide Metre Bridge, on polished mahogany sole, with platinoid wire and sliding platinum contact, graduated scale i metre long 5341s Slide Metre Bridge, as above but only J metre long £2 10 £1 15 0 0 CROSS STREET- HATTCnST GARDEN E-C 970 BAIRD &TATLOCK (LONDON) LTD. JB 5342 5342s Ostwald's Slide Metre Bridge, i metre long, platinum iridium wire .. £1 15 6 5343 5343s Wheatstone Bridge, wire i metre long, scale 0-50 cm. twice, mounjted on frame with jockey £0 15 0 5344 5344s Kohlrausch Universal Bridge, as illustrated 5345s Kohlrausch Universal Bridge, as illustrated, but fitted with coil This type of bridge is very convenient as the resistance can be read off on a scale in ohms direct without reference to a table of value. The Rheostat contains 5 comparative coils of o.i, I, 10, 100, 1,000, and the bridge is suitable for resistance measurements on solid conductors between about 0.05 and 20,000 ohms with sufficient accuracy for most technical purposes. By using the alternating current of the small induction coil fitted with the instrument, and substituting a suitable telephone for the galvanometer, the resistance to earth, of earth connections and the internal resistance of cells can be determined. £8 15 0 £10 15 0 ' 5346 5346s Lamp Resistance, so arranged that the lamps can either be used in parallel or series, on mahogany board, fitted with cover, with plugs for six lamps. Price, without lamps (The resistance can be varied according to the candle-power of the lamp.) £250 iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &. WLOCK (LONDON) LTD. 5347 5347s Galvanoscope, with glass scale, on foot . . 53505 Voltmeter, o-io volts 5351s Ammeter, o-io amps, (as Fig. 5350) (For complete list of Voltmeters see our Physica Apparatus list.) • '...:.,•> •• •: b- . 5352-5356 . ... - ,.;,'. .x. ' . '. '. . Ammeter, for students' use, in polished walnut case, gravity type, with accurately divided' scale — 5352s o-i amp. in T^jths 5353s 0-3 „ ^ths 5354s 0-5 „ 5355s o-io „ 5356s 0-20 „ |ths Voltmeter, as above — 5357s o-i volts in TJ0ths 5358s 0-3 „ 5359s 0-5 „ 5360s o-io „ 5361s 0-20 Jths £1 12 6 £1 12 6 £1 12 6 £1 12 6 £1 16 0 972 BAIRD &. TATLOCK (LONDON) LTD. 5362 5363 5364 5362s Plug Key Switches, on ebonite base— 2346 connections. 10/- 15/- 20/- 24/- each. 5363s Plug Key Switch, on ebonite base, with accurately fitted plugs — 123 way. 10/- 12/- 14/6 each. 5364s Plug Key Switch, on ebonite base, double, with four quadrants and two plugs . . 53t53 Plug Keys, with one plug, on mahogany base. (See Stewart & Gee, Fig. 67) 5365 £0 16 0 £060 5366 5367 A5368 5366s Lever Switches, with nickel-plated brass fittings, on ebonite base. i 2/6 3 3/6 4 way. 4/- each. 5367s Lever Switches, on round polished teak base, with, brass fittings — 123 way. 5/- 6/- 7/- each. 5368s Lever Switches, on round base, cheaper form — 123 way. 1/6 2/- , 2/6 each. A53683 Plug Key Switches, on ebonite base . . •'. . : . . £050 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 973 _ _ BAIRD &, TATLOCK. (LONDON) LTD. 5369 5370 5369s Resistance Frame of Iron, with contact studs mounted on slate, with eight coils for the resistance, of i to 18 ohms .. 5370s Resistance, on iron frame, 12 in. by 12 in., with two rows of coils and double switch with resistances to carry : — A. Resistance 100 ohms to carry i amp. Resistance in proportion. Arranged to stand on bench or to hang on wall £276 5371-5376 Electro Motor and Starter Resistance, mounted on board, arranged for continuous current. Motor Wound for 220 Volts. Horse-power. Revolutions per Minute. Price. 5371» * 1,900 £4 14 0 5372' 1 i.ooo £800 5373^ i i ,000 L350 £9 10 0 5374s 5375s 5376s Motor Wound for no Volts. Horse-power. Revolutions per Minute. Price. | 1,900 £440 £800 £9 10 0 1,000 1,350 These motors will be found very convenient for driving stirrers, shakers, etc., as they can be regulated to whatever speed required. 974 BAIRD &1XTLOCK (LONDON) LTD. 5377 5377s Portable Batteries, fitted in polished hardwood case, with lid, leather handle, and brass terminals. Portable Lithanode batteries are now universally used for traction and for actuating motors. Their lightness, freedom from disintegration and capability of abnormally high rates of discharge render them eminently useful in many directions. Their low internal resistance, constancy, and absence of local action make them unrivalled for medical and laboratory purposes, specially for X-Ray work as now adopted in all the principal hospitals throughout the United Kingdom and the Colonies. The large repeat orders from the War Office during Egyptian and South African campaigns speak for their utility and practicability in the field. Practical results in wireless telegraphy, scientific research, etc., have proved that they retain their efficiency for many months, without recharging, as illustrated. The illustration represents a 6-cell 30 A.H. battery fitted with terminals to each cell, so that 2, 4, 6, 8, 10, or 12 volts can be taken at will. STANDARD SIZES, WITH APPROXIMATE WEIGHTS PER CELL. No. of Cells. 14 AH. 21 A.H. 30 A.H. 45 A.H. 60 A.H. 90 A.H. 180 A.H. I Size 2 £0 17 6 4iX2fX7 £176 £110 4iX3^X7 £1 14 0 £150 7iX3X7| £226 £1 10 0 7*X3fX7 £2 12 0 £1 16 0 7iX4fX7j £330 £250 7jx6x7* £416 £3 18 0 Size 3 Size 4 £1 17 9 4ix6fx7 £280 £270 4ix8|x7 £300 £300 7iX7*X7j £3 17 6 £3 14 0 7iX9iX7i £4 16 0 £4 10 0 7ixxxfX7l £5 17 0 £5 17 0 Size 5 Size 6 Size £2 18 3 £3 13 0 £386 4^x12x7 £460 4j X 16 x 7 £4 15 0 ixxxfX7 £5 12 6 £5 18 0 7Jxi5fX7 £700 £740 Approx. weight per cell 3^ Ibs. with acid 51 Ibs. 7 Ibs. 10 Ibs. 12 Ibs. 21 Ibs. 40 Ibs. The prices given include extra terminals, so that 2, 4, 6, 8, 10, or 12 volts can be taken at will, according to the number of cells used. 5378 5378s Induction Coil, for determinations of conductivity, as devised by Nernst. It consists of a small coil with few windings, fitted with a light hammer made of an oscillating wire carrying a soft iron core in the centre, adjusted to vibrate very rapidly. Price, mounted on vulcanite base £1 10 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. v2?*E~ — BAIRD &TATLOCK (LONDON) LTD. 5379 5380-5381 5379s Coil, low resistance 5380s Ammeter and Voltmeter, combined, 5 volts and 5 • amperes, with first ampere divided • • •„ in 5381s Ammeter and Voltmeter, 10 volts and 10 amperes £2 10 0 £2 10 0 5382 5382s Reflecting Galvanometer. Moving coil of Ayrton-Mather type, well damped and having quick action. May be readily converted for ballistic use by disconnecting the short circuited damping winding ; coil accessible, .easily re-suspended and well insulated. Efficient clamping device, actuated externally. Fitted with mirror i meter radius ; mirror of other radius or plane substituted on request. Approximate deflection per io-B amp. on scale at i meter for coil of 5 175 14,000 ohms. J5 90 350 mm. Reflecting galvanometer, with any one of above coils . . £400 -CROSS STREET • HATTON GARDETST, E-C 976 SeerioTsr XVII. PYROMETERS FOR OF HlOH TBMPfiRXTURES B. £r T. Pyrometers Calendar's Recorders Fery Radiation Pyrometer Mercury Steel Pyrometers Thermo-Electric Pyrometers 979-990 1002-1003 1005-1006 994- 1001 SecTio>r XVIII Calorimeters Junker's Mahler's Rowland Wild's. 1007-1022 1016 1017 1011 -1012 CROSS STREET. HATTON GARDEN. EC tftr 'fi BAIRD &TATLOCK (LOM)ON) LTD. fl^ ^v*-^^^^-'" -TEP^QC^-^J-Jisii^^^FSar- -^jjEg^^gj The following are the different Sections in our Catalogue. Those marked * are also printed separately. Pages Nos. Section No. 1.* Laboratory Fittings 14-56 »i 2.* Bacteriological Apparatus 57-161 ** 3. Chemical Physiology Apparatus 162-192 99 4.* Microscopes and Microscopical Accessories 193-320 > 1 • 5.* Balances and Weights 321-382 » » 6.* Chemical Apparatus 383-816 » » 7.* Botanical Apparatus 817-842 f » 8. Gas Analysis Apparatus 843-886 » » 9.* Milk Analysis Apparatus 887-894 tt 10. Refractometers 895 - 902 f > 11." Oil Analysis Apparatus 903-926 »» 12. Water Analysis Apparatus 927-933 1 » 13. Cement Testing Apparatus 934-946 »t 14. Leather Testing Apparatus 947-949 t f 15. Paper Testing Apparatus 950-951 * » 16. Physico Chemical Apparatus 952-976 t t 17.* Pyrometers 977-1006 99 18.* Calorimeters 1007-1022 99 19.* Seed and Soil Analysis Apparatus 1023-1042 9 9 20.* Spectroscopes and Polariscopes 1043-107S 9t 21. Volumetric Apparatus 1079-1087 1* 22. Anatomical Models 1088-110 » » 23. Meteorological Apparatus 1106*1124 ., 24." Assay Apparatus 1125-117 25." Chemicals 1187-124 itt^. ll\l 14 ' CROSS STREET • HATTCTN GARDETST, ^- /«fj\ E'°' H RAIRD &1ATLOCK (LONDON) LTD. SECTION No. 17. Water and Electrical Pyrometers for the Measurement of High Temperatures. JFtgL 5383 (Section) Siemens' Water Pyrometer. The pyrometer is shown in sections in the accompanying sketches. It consists of a cylindrical copper vessel provided with a handle, and containing a second smaller copper vessel with double walls. An air space, a, separates the two vessels, and a layer of felt the two walls of the inner one, in order to retard the exchange of temperature with the surroundings. The inner vessel holds a little over one pint of water. A mercury thermometer, b, is fixed close to the wall of the inner vessel, its lower part being protected by a perforated brass tube, whilst the upper projects above the vessel and is divided as usual on the stem into degrees, Fahrenheit or Centigrade, as desired. At the side of the thermometer there is a small brass scale, c, which slides up and down, and on which the high temperatures are marked off in the same degrees into which the mercury thermometer is divided ; on a level with the zero division of the scale a small pointer is fixed to it, which passes in front of the thermometer. jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 977 BAIRD &TATLOCK (LONDON) LTD. Short cylinders, d, of either copper, iron, or platinum are supplied with the pyrometer, which are so adjusted that their heat capacity at ordinary temperature is equal to one-fiftieth part of that of the copper vessel filled with one pint of water. How- ever, as the specific heat of metals increases with the temperature, allowance is made on the brass sliding scales, which are divided according to the metal used for the pyrometer cylinders, d. It will therefore be understood that a different sliding scale is required for each kind of metal. In order to obtain accurate measurements, each sliding scale should only be used in conjunction with its own thermometer, and in case the latter breaks, a new scale must be made and graduated for the new thermometer. The water pyrometer is to be used as follows : — Exactly one pint (0.568 litre) of clean water, preferably distilled or rain water, is poured into the copper vessel, and the pyro- meter is left for a few minutes to allow the thermometer to attain the temperature of the water. The brass scale c is then set with its pointer opposite the temperature of the water as shown by the thermometer. Meanwhile one of the metal cylinders has been exposed to the high temperature which is to be measured ; and after allowing sufficient time for it to acquire that temperature, it is rapidly removed and dropped into the pyrometer vessel without splashing any of the water out. The temperature of the water will now rise, and after an interval the mercury of the thermometer will become stationary. When this is observed, the degree on the thermometer is .read off, as well as the division on the brass scale, s, opposite the top of the mercury. These two values added together give the temperature of the flue, furnace, or other heated space in which the metal cylinder had been placed. With cylinders of copper and iron, temperatures up to 1,800° F. (1,000° C.) can be measured, but with platinum cylinders the limit is 2,700° F. (1,500° C.). For ordinary furnace work either copper or wrought-iron cylinders may be used. Iron cylinders possess a higher melting point, and have less tendency to scale than those of copper, but the latter are much less affected by the corrosive action of the furnace gases ; platinum is, of course, not subject to any of Ihese disadvantages. The weight to which the different metal cylinders are adjusted is as follows : — Copper ... ... ... ... ... ... 137 grammes. Wrought-iron ... ... ... ... ... ... 112 „ Platinum ... ... ... ... .. ... 402.6 „ In course of time the copper cylinders lose weight by scaling ; the table which now follows gives for the diminished weights the factor with which the readings on the brass scale have to be multiplied in order to obtain the correct temperature. Table of Corrections for the Decrease in Weight of the Copper Cylinders. Weight of Copper Multiplier for the indications Weight of Copper Multiplier for the indications Weight of Copper Multiplier for the indications Cylinder in of the Cylinder in of the Cylinder in of the grammes. Sliding Scale. grammes. Sliding Scale. grammes. Sliding Scale. 137 I.OOO 131 1.046 125 1.096 136 1.007 130 1-054 I24 I.I05 135 1.015 I2Q 1.062 123 I.II4 134 1.022 128 1.070 122 I.I23 133 1.030 127 1.078 121 I.I32 132 1.038 126 1.087 I2O I.I42 5383s Siemens' Water Pyrometer, with thermometer 1,000° C. or 1,800° F., and seven copper cylinders, complete A53835 Siemens' Water Pyrometer, with eight cylinders of wrought-iron instead of copper . . B5383S Siemens' Water Pyrometer, with one cylinder of nickel and thermometer i 400° C or 2,550° F. . . Accessories for above. A. Spare Thermometer and scale, 1,000° C. or 1,800° F. B- •• .. ,, 1,400° C. or 2,550° F. C. Spare Sliding Scale D. Spare Copper Cylinders . . . . . . each E. Spare Wrought-iron Cylinders .. F. Spare Nickel Cylinders . . G. Platinum Cylinders (according to market prices of platinum) about When ordering spare thermometers and scales please state if required ° C, or ° F. scale, and if (or use with nickel, iron, copper, or platinum cylinders. £4 10 £4 10 £4 10 0 CROSS STREET • HATTON GARDETST, E-C BAIRD &.TATLOCK (LONDON) LTD. Fig. i. Practical Pyrometer, Wall Type Outfit. About one-tenth full size. The Indicator has Patent Spring-mounted Jewels, and is provided with a Red Adjustable Index (shown at 650°), by which the user can see from a distance if the desired temperature is maintained. PRACTICAL PYROMETERS. INTRODUCTORY. The great success attending the introduction of instruments " designed by an engineer for the use of engineers " has led to an extension of the types made to meet the widening field of use. With the adoption of the Hoskins Patent Alloys, we are able to extend the range of measurement. By virtue of the force developed by these Alloys and the use of Patent Spring Jewel-Mounting, these instruments are more powerful and more robust than can be made by any other method. " High Power " Pyrometers. — Reference to the Theoretical Notes on following pages will demonstrate the means whereby these instruments operate with a greater force than can be had in any other type. It is sufficient to say here, that the practical result is to make these pyrometers able to withstand the rough usage often unavoidable in industrial work. The user is not asked to alter his manufacturing methods to suit the pyrometer. The pyrometer has been specially designed to meet his needs and conditions. Pyrometers a Necessity. — On the general need for a pyrometer in every heat operation it is hardly necessary to dwell. There is a right heat for every operation and all other heats are wrong. The only certain way to repeat good results and avoid bad ones is to measure the temperature regularly. Simplicity.— No special skill is required to set up or use these PRACTICAL PYROMETERS. Each outfit is complete, tested and adjusted for immediate use and is provided with every detail down to the screws for fixing, and full instructions for use. The temperature can be read on the indicator or recorder as easily as the time on a clock. The divisions and figuring are bold and can be read at a distance. See Figs. 3 and 5. A pyrometer outfit comprises one or more stems, connectors and cables and either an indicator or recorder. See Figs. I, 2 and 10. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &. TATLOCK (LONDON) LTD. The Stem.— The stem which is heated contains two alloys joined together at the sensitive end. The heating of the junction generates an electric current which actuates the indicator or recorder. The more the Fig. 2. — Practical Pyrometer, Portable Outfit. About one-quarter full size. The full length of the Stem is not shown, the tip being cut off for convenience. junction is heated, the higher is the current. The Hoskins Patent Alloys enable this current to be large, thus making the whole apparatus robust. The internal construction of the stem varies with the maximum temperature it has to withstand, but in all the standard types for shop use the construction embodies a stout steel tube f in. diameter. In the type for use up to 600° C. (noo°F.) the steel tube is pierced to allow the heat to reach the sensitive junction, thus securing very rapid action. Up to 1050° C. (1900° F.) the protection is heavier, while for temperatures above this a special refractory protection is used inside the steel tube, so that the burning away of the tube does not put an end to the use of the stem. It should be noted that in none of the stems is there any platinum wire ; nor porcelain, quartz, or other fragile material. Cold End Extension. — For reasons which are explained on following page, it is desirable that the point where the alloys of the stem join the cable should be at a steady low temperature. In fixed installations this would often necessitate a very long stem. To avoid this we supply a cold end extension with fixed outfits, composed of similar alloys to the stem. This extension, which is twenty-four inches long, adds to the effective length of the stem by that amount, but does not have to be replaced in the case of renewals. Fig. 3. — Scale of Indicators. About full size. -CROSS STREET • HATTOTST GARDETST, E-C 980 BAIRD &TATLOCK (LONDON) LTD. Indicators. — Two types of indicating instruments are made, the Wall Type (see Fig. i), for fixed use, in a metal case with nickel-finished front ; and the Portable (see Fig. 2), in a polished hardwood case with a leather carrying handle. In both indicators the moving coil which carries the pointer over the scale is mounted on PATENT SPRING-MOUNTED JEWELS, thus providing a frictionless movement guarded against damage by rough usage. The Wall Type Indicator has an adjustable red index which can be set to any desired tempera- ture, and the user can then see from a distance when the black moving pointer departs from the desired temperature (see Fig. i). Recorder. — Where a permanent record of the temperature is to be kept, an automatic recorder is used. This instrument draws an ink line on a paper chart, thus showing what the temperature has been at all times. A chart of this kind is essential where regularity of work is required. The temperature may be read from the recorder at any instant without disturbing its record, and after the heating is over the record chart, showing the whole temperature history of the work, can be filed for reference with other particulars of the job in hand. Absence of Pen Friction. — In order to avoid errors due to friction of the pen upon the chart, a special design is employed (see Fig. 4). The marking pen swings freely in front of, Jsut not touching the chart. Periodi- cally the pen is pressed upon the chart by a clock-driven presser bar, thus leaving a dot which records the tempera- ture. The successive dots join into a continuous line showing the rise and fall of the temperature. The pen has Fig. 4. — Automatic Recorder. About one-seventh full size. an inking device which takes up ink from a pad on the presser bar and transmits it to the paper, the particular construction preventing excess of ink, which would make a blot, and at the same time one charge of ink on the presser bar lasts for several days. The moving coil which controls the pen is carried by PATENT SPRING- MOUNTED JEWELS, similar to those in the Indicators, and it is not liable to damage due to vibration. There is no delicate suspension to break. Charts. — The recorder charts are circular, ten inches in diameter, thus allowing the whole of a record to be seen without disturbing the recorder. They are printed for one revolution in twenty-four hours, but it is possible to allow the same chart to run two or three days, as, for instance, over Sunday, or to cover the whole firing of a pottery kiln, the line for each day being readily distinguished. The temperature scale is open, thus ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 981 - - BAIRD &TATLOCK (LONDON) LTD. c Fig. 5. — Part of Recorder Chart. About full size. allowing very accurate readings. Fig. 5 shows a portion of a chart. The great width of the chart giving fine readings, should be noted. Where desired, the recorder can be fitted with an alarm contact to ring a bell whenever the temperature reaches a pre-determined limit. Laboratory Apparatus.— The simplicity which has proved advantageous in the works is also appreciated in the laboratory, and some useful special outfits and accessories have been devised for experimental work. Recalescent Outfit.— It is generally known that each grade of steel has a critical temperature above which it must be heated before quenching will harden it. In high carbon steels the passing of this critical temperature in cooling is accompanied by what is known as " recalescence." The steel, as it gives out heat gets cooler until Fig. 7. — Recalescent Outfit. About one-sixth full size. the critical point is reached, and then, though it still continues to give out heat, there is a " halt " in the fall of the temperature. To find the " recalescent point " is therefore the first step towards laying out a hardening programme. There are several ways of doing this, but the quickest and simplest is with the outfit we have designed for the purpose. A small sample of the steel is drilled and slipped on the tip of a small Hoskins Thermo-couple. This couple has its " cold junction " immersed in an oil vessel. A portable indicator having a specially fine scale and pointer is connected to the stem by means of a flexible cable. The sample is now heated by a Bunsen gas flame till its temperature as shown on the indicator is over 850° C., the flame is then removed and the sample allowed to cool. The fall of the reading on the indicator is continuous till the critical or recalescent point is reached when the pointer will " halt " for a few seconds. Steel of this quality must be heated to certain excess above the " halt " point in order that it may be hard when quenched. Usually, for small work, not exceeding half-inch in diameter, 30° C. excess over the recalescent point will give good results. Of course, actual trial will be needed to get the best final results. A recorder may be used in place of the indicator, thus automatically recording the " halt " point. For this work the recorder is made with a specially open scale and the chart is revolved more rapidly. Special quotations will be given for outfits for this and other research work. CROSS STREET • HATTQTST GARDEN, E;C 982 BAIRD &TATLOCK (LONDON) LTD. EXPLANATION OF FIGURE 8. ©T'rTTT 1. [r^n Fig. 8 To illustrate the application of standard stems and accessories the typical examples shown in Figure 8 are chosen. The drawings are not to scale, and it will be understood that any desired combination of stems and accessories may be made to suit a particular case. Station 1. — Stem type No. 5428 with pocket No. 5441, allowing removal without interruption of pipe service. For use up to 500° C (930° F.). Dimensions. — P3, J-inch Whitworth Pipe Thread ; a, 2| inches, suitable for pipes of inside diameter 3 inches or over ; b, total length overall 10 inches. Examples.— Steam Pipes, Superheaters, Gas from Producers and Exhaust from Internal Combustion Engines. Station 2. — -Stem type No. 5419, with Clamp Flange No. 5434, to regulate depth of insertion. May be horizontal if desired. Dimensions. — K, about 5 inches diameter, clamps on stem with set-screw ; c, not less than 3 inches ; d, to give required depth e ; t, not less than 12 inches, usually balance of 36 inch stem. Diameter of stem f-inch. Examples. — Flues from Boiler Furnaces or Gas Retort Benches, High Temperature Bake Ovens. Station 3. — Stem type No. 5419, bent stem No. 5435 to keep it out of the way of work and to keep " cold junction " e cool. Clamp Hook, No. 5333, to regulate depth of insertion. Dimensions. — d, at least 3 inches in liquid ; k, enough to give required depth d ; h, enough to keep Connector C away from furnace heat, k and h are usually made each 19 inches unless otherwise ordered. J clamps on stem by set-screw and is supplied with f-inch Whitworth bolt and nut for attachment to side or lip of vessel. Examples. — Baths of Oil or Low-melting Salt- Varnish Vats. For Metal baths see Stations 6 and 8. Station 4. — Stem type No. 5419 or No. 5420, bent stem No. 5435, to take Inverted Weatherhood, No. 5446, Union Connection, No. 5445, for attachment direct to metal wall with advantage of tight joint and quick removal. If temperature is over 600° C (i 100° F.), or if it is necessary to remove stem without opening vessel to air, use also Wrought-Iron Sheath, No. 5436, and Bushing, No. 5437. I 983 BAIRD &TATLOCK (LONDON) LTD. this fitting ; N, if used, I inch Whitworth Pipe Thread. Diameter of H, il inches. Examples.— Hot Air Main and Downcomer of Blast Furnace, Carburettors and Superheaters of Water Gas Plants, Ducts from large Gas Producers. Station 5.— Stem, type Nos. 5419, 5421 or 5422, bent stem No. 5435, to keep it out of the way of work and to keep " cold junction " e cool. Clamp Flange, No. 5434, fixed to wall of furnace. If stem is inserted through the top, No. 5434 need not be fixed to furnace. For continuous work between 800° and noo°C (1470° and 2000° F), use also Wrought-lron Sheath, No. 5436 ; over 1100° C (2000° F) use Refractory Sheath, No. 5442. No. 5436 screws into No. 5434. Dimensions.— K, about 5 inches diameter, supplied with three f-inch Whitworth Screws for fixing to furnace wall t-inch and M or P5 ij inches diameter ; e, without sheath, at least 3 inches if unlined, or i| inches if brick-lined ; if with Sheath M P5, at least 5 inches or 3 inches respectively ; d, to give required depth e ; h, 18 inches unless otherwise ordered. Examples. — Small Furnaces for Tempering, Hardening, Carbonizing, High Speed Steel Treatment, and General Experimental Work. Station 6.— Stem, type No. 5420 or No. 5421, bent stem No. 5435, to keep it out of the way of work and to keep " cold junction," e, cool. Clamp Hook, No. 5433, holding stem. Alloy Sheath No. 5438 screws into No. 5433. Dimensions. — g, at least 5 inches in liquid ; d, 12 inches unless specially ordered otherwise ; h, enough to keep C away from furnace heat, usually 18 inches unless ordered otherwise ; J is supplied with f-inch Whitworth bolt and nut for attachment to side or lip of vessel. Examples. — Baths of Lead or High-Melting Salt up to iooo°C, Galvanizing, Tinning and Solder Baths, Aluminium and Low- melting Alloys. For Barium Chloride Baths above 1000° C, with Stem No. 5432 and Refractory Sheath No. 5442. Station 7. — Stem, type No. 5420, No. 5421 or No. 5422. Clamp Flange No. 5434, to regulate depth of insertion and to hold Alloy Sheath No. 5440 or Refractory Sheath No. 5442. Stem inserted in recess to shelter it from cutting action of Furnace Gases. Upright Weatherhood, No. 5447, for out of doors or dirty situations. Dimensions. — e, at least 3 inches ; m, at least 3 inches square ; d, enough to give required depth e ; P2 or P5 screw into K, which is about 5 inches in diameter ; f, not less than 12 inches, usually balance of Standard 36 inch stem. P2 or P5, ij inches in diameter. Examples. — Large Direct Fired Furnaces for Hardening, Carbonizing, Annealing and Pre-heating ; Kilns for Brick, Porcelain or Glass Enamelling ; Combustion Chambers not over 1200° C ; Gases from Regenerators of Open-hearth Furnaces. Station 8. — Special stem, type No. 5430, bent stem No. 5435, with Refractory Sheath and Clamp Socket No. 5443 and Hand-guard No. 5432. Connector and 20 ft. Flexible Cable No. 5453 with Portable Indicator. Alternatively this stem may be connected to a Wall Type Indicator. Dimensions. — g, not less than 4 inches nor more than 6 inches, unless specially ordered ; k and h each 24 inches unless ordered otherwise ; P6 clamps on stem and is adjustable to allow of repair of Stem in case of breakage of Refractory Sheath. Examples. — Molten Iron, Brass, Bronze and Gun-metal not over 1300° C. Station 9. — Stem, type No. 5420 or No. 5421, bent stem No. 5435, to keep it out of the way of work. Inserted through side and crossing outer fire space. Brick protection cutting off fire from stem is required as shown. Clamp Flange No. 5434 holding stem. For temperatures up to 9OO°C (i66o°F) use Wrought-lron Sheath No. 5436, above that use Alloy Sheath No. 5440. Either of these screws into No. 5434. The Outfit is shown with Wall Type Indicator in Dust-proof Cover No. 5436, in view of the furnace operator, and Recorder in manager's office. Dimensions. — k about 5 inches in diameter, M or P2, ijinches diameter and 18 inches long unless otherwise ordered, e, atleast 3 inches ; d, sufficient to give required depth e ; h, usually 18 inches unless ordered otherwise. Examples. — Muffle Furnaces with Outer Fire Space, for Tempering, Hardening, Carbonizing, Annealing, Re-heating, etc. The Outfit shown is particularly useful where long runs are made. Directions for Ordering. Single Outfits, both Standard and Special, are listed on pages 985-986. Accessories and Extras may be added as required. Their applications are shown in Figure 8 and the prices on pages 987 and 990. Should none of the complete outfits apply, it is advisable that information on the points indicated below should be stated, so thata suitable combination may be selected. If this is not possible a selection may be made from the separate items listed on pages 987 to 990. each single outfit comprising a Stem, Connector, Cable and Indicator or Recorder ; if for fixed installation an Extension is also needed with the Cable. Recommendations and quotations will be submitted free of charge on receipt of information on the points named below. I . — What are the processes and types of apparatus for which the Pyrometers are wanted ? 2. — Is the furnace, or other containing vessel at atmospheric pressure ? If not, state the actual maximum pressure or draught. 3. — What are the highest and lowest temperatures to be measured ? Is the scale to be Centigrade or Fahrenheit ? 4. — State whether it is intended to use a Wall Type (fixed) or Portable Indicator, or a Recorder. A combined outfit with Wall Type Indicator and Recorder is often the most useful. See Station 9, Figure 10. 5. — What are the dimensions of Stems ? What accessories are wanted ? Figure 10 shows the kind of information wanted. f in doubt, send sketches, drawing, or blue prints of apparatus. 6.— What is the average temperature where the " cold junction " e is to be placed (see Figure 10) . If no information is given on this point, it will be assumed at 30° C (90° F), but the user can alter the setting at will. 7.— What is the length of Cable needed to connect each Stem to the Indicator or Recorder ? (See Standard lengths on 585). Allow enough for bends and "up and down "wiring. Are there any long spans or other difficulties in running Cables ? Spare Parts.— It is always advisable, particularly on export orders, to order at least one spare Stem and Sheath of each kind ed. This saves delay when renewals are needed. When subsequently ordering parts for instruments already delivered, the type and serial numbers marked on those instruments should be quoted 984 es^sr BAIRD&.lArLOCK(LONDCfN)LTD. IFK3>^^r^ ^s PRICES OF SINGLE STANDARD OUTFITS. Wall Type Outfits, comprising 36-inch straight stem, f in. diameter, connector, 24-in. cold end extension, 36 feet cable with insulators and screws, and wall type indicator in metal sf^^^m case with nickel-finished front (see Fig. i, page 979), scaled as below :— 53841 Pyrometer, Range, 150° to 600° Centigrade £6 17 6 5385T Pyrometer, „ 200° „ 900° £776 5386T Pyrometer, „ 300° „ 1050° £826 53871 Pyrometer, „ 300° „ 1200° £826 5388T Pyrometer, „ 400° „ 1360° £950 5389r Pyrometer, „ 300° „ 1100° Fahrenheit £6 17 6 5390r Pyrometer, „ 300° „ 1660° £776 53911 Pyrometer, „ 600° „ 1900° £826 5392r Pyrometer, „ 600° „ 2200° £826 53931 Pyrometer, „ 800° „ 2500° £950 Portable Outfits, comprising 36-in. straight stem, f-in. diameter, connector, 20 feet flexible cable and portable indicator in polished hardwood case with carrying handle (see Fig. 2, page 980), scaled as below : — 5394T Pyrometer, Range, 150° to 600° Centigrade £800 5395r Pyrometer, ,, 200° „ 900° £8 10 0 5396T Pyrometer, ,, 300° „ 1050° £950 5397r Pyrometer, „ 300° „ 1200° £950 5398T Pyrometer, „ 400° „ 1360° £10 5 0 5399r Pyrometer, „ 300° „ 1100° Fahrenheit £800 5400T Pyrometer, „ 400° „ 1660° £8 10 0 5401T Pyrometer, „ 600° „ 1900° £950 5402r Pyrometer, „ 600° „ 2200° £950 54031 Pyrometer, „ 800° „ 2500° £10 5 0 Recording Outfits, comprising 36-in. straight stem, f in. diameter, connector, 24-in. cold end extension, 36 feet cable with insulators and screws, and recorder (see Fig. 4, page 981 ), in polished hardwood case, with lock and key and 100 charts, scaled as below. Centi- grade ranges usually in stock, Fahrenheit to order only. 5404T Pyrometer, Recording Range, 150° to 600° Centigrade £21 10 0 5405T Pyrometer, ,, „ 200° „ 900° £21 10 0 54061 Pyrometer, ,, „ 300° „ 1050° £21 12 6 54071 Pyrometer, „ „ 400° „ 1360° £22 7 6 5408T Pyrometer, „ „ 300° „ 1100° Fahrenheit £21 10 0 54091 Pyrometer, „ „ 400° „ 1660° £21 10 0 5410T Pyrometer, „ „ 600° „ 1900° £21 12 6 54111 Pyrometer, „ „ 800° „ 2500° £22 7 6 =^tf«^w» [ n CHEMICAL AND SCIEOTIFIC~APPARATUS AND PURE CHEMICALS Jf /I I/_!\ // V. *A —• i\ /*-=•• "^^ T^iiiSi^iJSiLi^ 9 **~f^-1£&£> 985 vixsfcr BAIRD &TATLOCK (LONDON) LTD. £7 13 0 £22 17 0 PRICES OF SELECTED OUTFITS FOR SPECIAL PURPOSES. 541 21 Superheater of Boiler Plant, Indicating. One No. 5427 Stem, 5 by | in. See Station i, Fig. 8. One No. 5441 Pocket, T.\ by f in. Whitworth Pipe Thread. One No. 5450 Connector, 24 in. Extension and 36 ft. Cable with Insulators and Screws. One No. 5459 Wall Type Indicator, 300° to 1100° F. 5413' Hot Air Main of Blast Furnace, Recording. One No. 5420 Stem, 36 by f in., bent at centre. See Station 4, Fig. 8. One No. 5444 Union Connection. Two No. 5436-8 Sheaths 8 in. long (one spare). One No. 5437 Bushing, i in. Whitworth Pipe Thread. One No. 5446 Inverted Weatherhood. One No. 5450 Connector, 24 in. Extension and 36 feet Cable with Insulators and Screws. One No. 5475 Recorder, 200° to 900° C. One hundred Charts. 5414T Galvanizing, Tinning or Lead Bath, Indicating. One No. 5420 Stem, 36 by f in., bent at centre. See Station 6, Fig. 8. One No. 5433 Clamp Hook. Two No. 5438 Alloy Sheaths, 12 in. long (one spare). One No. 5450 Connector, 24-in. Extension and 36 feet Cable with Insulators and Screws. One No. 5455 Wall Type Indicator, 200° to 900° C. £8 17 6 5415T Recalescent Point of Steel, Portable Indicating. One No. 5429 Small Stem, 6 in. long, with bare tip. See Fig. 7. One Stand with Shield, terminals, " cold junction " flask and thermometer. One 20 ft. length of Flexible Cable, with tangs. One Portable Indicator, o° to 900° C., with special fine scale and " knife edge " pointer. £11 0 0 5416T Small Furnace for Hardening, Tempering or Carbonizing, Indicating. One No. 5420 Stem, 36 by f in., bent at centre. See Station 5, Fig. 8. One No. 5434 Clamp Flange. Two No. 5436-6 Sheaths 6 in. long (one spare). One No. 5450 Connector, 24-in. Extension and 36 ft. Cable with Insulators and Screws. One No. 5456 Wall Type Indicator, 300° to 1050° C. £906 5417T Large Furnace for Carbonizing and Annealing, Combined Indicating and Recording. Two No. 5420 Stems, 36 by f in. See Station 7, Fig. 8 (one spare). One No. 5434 Clamp Flange. Two No. 5440 Alloy Sheaths, 18 in. long (one spare). One No. 5447 Upright Weatherhood. One No. 5450 Connector, 24-in. Extension and 36 ft. Cable with Insulators and Screws. One No. 5456 Wall Type Indicator, 300° to 1050° C. One No. 5486 Dustproof Cover for same. 72 ft. Additional Cable to Recorder, with Insulators and Screws. See Station 9, Fig. 8. One No. 5476 Recorder, 300° to 1050° C. One hundred Charts. £32 8 5418T Molten Brass, Gun-metal or Iron (not over 1300° C.). Portable Indicating. One No. 5430 Stem, 48 by f in., bent at centre. See Station 8, Fig. 8. One No. 5443 Refractory Sheath and Socket. One No. 5432 Handguard. One No. 5453 Connector and 20 ft. Flexible Cable. One No. 5468 Portable Indicator, 400° to 1360° C. £12 12 6 . 14 -CROSS STREET • HATTO^K GARDETST, E-C 986 <2^r BAIRD &. TATLOCK (LONDON) LTD. per inch, 2Jd.; base £0 15 0 i M 2Jd-: II £0 15 0 l> 3d.; »> £0 17 6 ff 8d.; tt £1 0 0 PRICES OF STEMS. Standard Stems, 36 in. long, §-in. diameter, for maximum temperatures as below. 5419T Maximum temperature, 600° C. (1100° F.) . . 5420r „ „ 1050° C. (1900° F.) . . 5421* „ „ 1200° C. (2200° F.) .. 54221 „ „ 1360° C. (2500° F.) .. Special Length Stems, similar to above, but of different length, made to order only. Up to a maximum of 120 inches the price may be calculated by adding the rate per inch, multiplied by the total length, to the base price below. For stems longer than 120 inches, special quotations will be given on receipt of particulars. 5423T Maximum Temperature, 600° C. (1100° F.) 5424T „ „ 1050° C. (1900° F.) 5425T „ „ 1200° C. (2200° F.) 54261 „ „ 1360° C. (2500° F.) Stems for Special Purposes. Those usually in stock are illustrated in the body of the catalogue, at the pages referred to below. Other stems made to order on receipt of particulars. 5427T 6 in. long, f-in. diameter, with Union Connection, f-in. Whitworth Pipe Thread for attach- ment to Steam Pipe or other metal vessel 5428T 6 in. long, f-in. diameter, with Pocket, f-in. Whitworth Pipe Thread, for insertion in Steam Pipe, etc. See Station i, Fig. 8 54291 6 in. long, f-in. diameter, with bare junction at tip and flexible wires from cold junction. For Recalescent Outfit or other experimental work, see Fig. 7 5430T 48 in. long, f-in. diameter, bent at centre, with bare junction at tip for use with Refractory Sheath No. 5443 in molten metals. See No. 5000, Station 8, Fig. 8 PRICES OF ACCESSORIES. 5431T Alarm Contact, fitted to Recorder with Bell, Battery, and 36 ft. Cable with Insulators and Screws . . 5432T Handguard, to clamp on Stem. See Station 8, Figure 8 . . . . . . . . 5433r Clamp Hook, with screw and nut. See Stations 3 and 6, Fig. 8 5434T Clamp Flange, with three screws. See Stations 2, 5, 7, and 9, Fig. 8 5435T Extra for Bending Stem, unless otherwise ordered, bent 90 degrees at centre of Stem. See Stations 3, 4, 5, 6, and 8, Fig. 8 5436T Wrought Iron Closed Sheath, screwed for attachment to No. 5433 or No. 5434. Stock length for 17^ in. below flange or hook. See Stations 4, 5, and 9, Fig. 8. Shorter lengths same price, longer pro rata, to order only Bushing for attaching No. 5436 to metal shell, i-in. Whitworth Pipe Thread. See Station 4. Fig. 8 Alloy Sheath, screwed for attachment to No. 5433 or No. 5434, for continuous use in baths or furnaces. See Station 6, Fig. 8. Stock length for 12 in. below hook £0 17 6 £0 17 6 £100 £1 12 6 £176 £1 10 0 £0 10 0 £2 15 0 £400 £0 10 0 £076 £076 £026 £040 £010 £086 £060 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- ^s 987 BAIRD &.TXTLOCK (LONDON) LTD. 5440T Alloy Sheath as No. 5439, fitted with Socket and Wrought-Iron Pipe Extension screwed for attachment to No. 5434 to give 17! in. below flange 54411 Pocket, with Dustcap for Stem No. 5428, screwed |-in. Whitworth Pipe Thread for Attach- ment to Steam Pipe or other metal vessel. See Station i, Fig. 8 . . 5442* Refractory Sheath, 7 in. long, used as renewal on No. 5443 below, also for direct attach- ment in small furnaces. See Station 5, Fig. 8 5443T Refractory Sheath, as No. 5442, fitted with Socket, sleeve and clamping screw for use in molten metals. See Station 8, Fig. 8 . . 54441 Union Connection, f-in. Whitworth Pipe Thread for attachment to metal vessel. See Station 4, Fig. 8 5445T Union Connection, f-in. Whitworth Pipe Thread for use with Stem No. 5428. See Station i, Fig. 8 5446T Inverted Weatherhood. See Station 4, Fig. 8 54471 Upright Weatherhood. See Station 7, Fig. 8 PRICES OF CABLES AND SWITCHBOARDS. 5448T Connector, to screw on Stem, alone 5449T Cold End Extension, 24 in. long, alone Special length Extensions, to order only at special prices. 5450T Connector, 24 in. Cold End Extension and 36 feet Cable for fixed installation, with Insulators and Screws . . 545 1T Ditto, but with 72 feet cable 5452T Ditto, but with 100 feet cable 5453T Connector with 20 feet Flexible Cable as used in Portable Outfits For cables of different lengths from the above, quotations will be given on receipt of particulars. The standard lengths are recommended ; any extra may be looped up. The cables must not be cut. PRICES OF INDICATORS. Wall Typ^e Indicator, with patent spring-mounted jewels, in metal case, with nickel- finished front, for use with Standard Stems and Cables, scaled as below : — 5454T Wall Type Indicator, range, 150° to 600° Centigrade 5455T Wall Type Indicator „ 200° 5456T Wall Type Indicator „ 300° 54571 Wall Type Indicator „ 300° 54581 Wall Type Indicator „ 400° 5459* Wall Type Indicator „ 300° 54601 Wall Type Indicator „ 400° 5461* Wall Type Indicator „ 600° 54621 Wall Type Indicator „ 600° 5463T Wall Type Indicator 800° , 900° „ 1050° „ 1200° I3600 „ 1100° Fahrenheit 1660° „ 1900° „ 2200° 2500° 988 BAIRD &. TATLOCKL (LONDON) LTD. Portable Indicator, with patent spring-mounted jewels, in polished hardwood case, with carrying handle, for use with Standard Stems and Cables, scaled as below : — 5464T Range, 150° to 600° Centigrade . . . . . . . . . . . . ..£650 900° „ .. £6 15 0 1050° „ .. .. .. .. .. .. .. £7 10 0 1200° „ .. .. .. .. .. .. £7 10 0 1360° „ .. .. .. .. .. .. .. £7 17 6 1100° Fahrenheit . . . . . . . . . . £650 1660° „ . . . . . . . . . . . . ..£6150 1900° „ .. .. .. .. .. .. .. £7 10 0 2200° „ .. .. .. .. .. .. .. £7 10 0 2500° .... £7 17 6 5465' „ 200° 5466' „ 300° 5467' „ 300° 5468* „ 400° 5469' „ 300° 5470' „ 400° 547 1T „ 600° 5472' „ 600° 5473' „ 800° PRICES OF RECORDERS AND CHARTS. Recorder, with Patent Spring-mounted Jewel Movement, in polished hardwood case with 3-ply back, for use on wall (see page 6), with chart speed one revolution in 24 hours, cali- brated for use with Standard Stems and Cables, over one of the ranges below . . . . £19 0 0 Charts, any Standard range ; . . . per 100 £0 12 6 Centigrade ranges usually in stock, Fahrenheit to order only. 5474' Range, 150° to 600° C. For use with Stem No. 5419 type. Chart No. 690. 5475' „ 200° „ 900° c. „ No. 5420 „ 990. 5476' „ 300° „ 1050° C. „ No. 5420 „ 1190. 5477' „ 400° „ 1360° C. „ No. 5422 „ 1390. 5478' „ 300° „ 1100° F. „ No. 5419 „ 690 F. 5479' „ 400° „ 1660° F. „ No. 5420 „ 990 F. 5480' „ 600° „ 1900° F. „ No. 5420 ,, 1190 F. 5481' „ 800° „ 2500° F. No. 5422 „ 1390 F. 5482' „ 700° „ 1400° C. Fixed Focus Pyrometer. Chart No. 1490. 5483' „ 900° „ 1800° C. ., i. 1890. 5484' „ 1300° „ 2560° F. tr I* 1490 F. 5485' „ 1600° ,, 3300° F. )« it 1890 F. ^CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 989 v£X*fe BAIRD &TATLOCK (LONDON) LTD. Extras on Recorders. 54881 Alarm Contact, fitted to Recorder, with Bell, Battery, and 36 ft. Cable with Insulators and Screws 54891 Dustproof Lock-up Cover for Recorder £100 Extras on Indicators. 5486T Dustproof Lock-up Cover for Wall Type Indicator only, in hard wood, see Station 9, Fig. 8 5487* Extra for Wall Type Indicator, with specially bold 7 in. scale for reading at a long distance, il . . db X V V to order only Indicators can be supplied to order to meet all conditions, amongst other varieties :— Double Scales, Centigrade and Fahrenheit. Two Ranges. Special Ranges. Special Calibrations.. Knife-edge Pointers for specially fine readings. Illuminated Scales for dark positions. Quotations will be given on receipt of particulars. £400 £1 10 0 90 / 80 ,. / / *2 z. 70 // t. t £&U / 60 CO > ^ _J 0 &L 50 13 n^ V £ f '^ $. .'' +0 z / / •^' u. / & * ^ fS 30 £ / ,*tl ff .^•', 'V LJ A f 0^ k- s r 20 / + f S ^^ ^ ^ / ,* / s~ |Q / /s ^ n M N0« wM I\\J1^ /-:- ^ ^f \ ^} AUW. 0 A _-- — — — .— -— ' TEI 1PER/ TD(RE •c' 0 1 00 2 00 4 08 4 00 5 00 6 00 1 00 8 00 9 00 10 00 II 00 12 00 Fig. 12.— Thermo-electro-motive forces. CROSS STREET • HATTCTN GARDEN, E-C 990 ess? BAIRD &TATLOCK (LONDON) LTD. 5492 Cones protected in furnace. 5492 5492T Seger Cones, for use up to 2000° C. . . . . . . . . per 100 Seger Cones or Pyroscopes have melting points which range from 590° C. to the melting point of platinum. A full list of these cones with their melting points is given below. The following table shows which cones are most adapted for use with various classes of goods :— Porcelain colours and lustres, Nos. 022 to oio. Goods manufactured from clays containing a considerable amount of lime and iron oxide (e.g., o.o., stove tiles), Nos. oisa to oia. Goods manufactured from clays poor in lime and iron (e.g., o.o., floor tiles), Nos. la to 10. Stoneware with salt or loam glaze, Nos. 5a to 10. White stoneware, etc. (hard burnt), Nos. 3a to 10. White stoneware, etc. (mild burnt), Nos. oio to oia. Cement and porcelain, Nos. 10 to 20. Refractory glazes, Nos. 20 to 25. For determining the fire-resisting power of refractory earths, etc., Nos. 26 to 42. MELTING POINTS OF SEGER CONES. Price, any No., IS/- per 100. £0 15 0 Cone No. Cent. Fahr. Cone No. Cent. Fair. Cone No. Cent. Fahr. Cone No. Cent. Fahr. O22 OOO III2 07a 960 1760 9 1280 2336 29 1650 3O02 O2I 650 1202 o6a 980 1796 IO 1300 2372 30 1670 3038 02O 670 I238 osa 1000 1832 II 1320 2408 31 1690 3074 Dig 690 1274 04a IO2O 1868 12 1350 2462 32 1710 3110 018 7IO 1310 O3a 1040 1904 13 1380 2516 33 1730 3146 Oiy 730 1346 O2a 1000 1940 14 1410 2570 34 1750 3182 016 750 1382 oia I08O 1976 15 1435 2615 35 1770 32l8 oisa 790 1454 la IIOO 2012 16 1460 2660 36 1790 3254 oi4a 815 1499 2a 1120 2048 17 1480 2696 37 1825 3317 oi3a 835 1535 3a 1140 2084 18 1500 2732 38 1850 3302 oi2a 855 1571 4a IIOO 2I2O 19 1520 2768 39 iSSo 3416 ona 880 1616 5a 1180 2156 20 1530 2786 40 1920 3488 oioa 900 1652 6a 1200 2192 26 1580 2876 4i 1960 3560 oga. 920 1688 7 1230 2246 27 1610 2930 42 200O 3632 o8a 940 1724 8 1250 2282 28 1630 2966 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 991 BAIRD &TATLOCK (LONDON) LTD. ~ -D — WATKINS HEAT RECORDER 5494 5493T Mercury Steel Thermometer for temperature up to 950° C. Length of L . , 20 30 40 50 60 70 ' 80 in. Price .. 80/- 82/- 84/- 88/- 92/- 98/- 105/- each. 5494T Watkin's Heat Recorders. Consists of a small block of very refractory ware, having circular recesses sunk into its top face, into which are placed little pellets of fusible materials of definite composition and melting point. The fusion point of each mixture has been carefully and accurately determined by comparison with a Standard Electrical Pyrometer. Place the Recorders in the Oven or Kiln in such parts as desired while setting in, taking care to mark the ends in under-glaze colour in such a manner as to indicate that position. I A. B. I A arch, B bottom, L left quarter. When fired examine carefully what alteration has taken place '•£'• | L. | in the form of the test pieces. It has been found from extensive experience that a range of 200 degrees C. will usually include the extremes of temperatures which can be allowed in any well conducted firing operations. For this reason the Recorders have been arranged in the following series, and opposite to each will be found an industrial firing operation for which that particular one has already been found suitable : Series of Recorders most Suitable for different Glasses of Ovens and Kilns. A * j- 3 5 7 9 Enamel Kiln. 3 5 7 9 ii „ „ *5 7 9 ii 13 Hard Kiln for Maroons, etc. 7 9 ii 13 15 »» » »» 9 ii 13 15 17 Soft Glaze Kiln for Tiles , etc. B *n 13 15 17 19 Hard Glaze ,, ,, 13 15 17 19 21 Rockingham and Easy Glost Ovens. 15 X7 19 21 23 Glost Oven (Hard). *i; 19 21 23 25 Earthenware Biscuit Oven. •19 21 23 25 27 „ (Hard). •"""MBtfTf'.sr-r- irym°» ^, >Js. £?tJ\Ym Mj| 14 • CROSS STREET • HATTOTST ^L^IR-.^^frsSSssy^^— GARDEN, E- C- M W- 992 BAIRD &TATLOCK (LOM3ON) LTD.! D E *2I 23 25 27 29 23 25 27 29 3i *25 27 29 3i 33 27 29 3i 33 35 29 3i 33 35 37 *3i 33 35 37 39 33 35 37 39 4i 35 37 39 4i 43 37 39 4i 43 45 39 4i 43 45 47- *4r 43 45 47 49\ 43 45 47 49 51 45 47 49 5i 53 47 49 5i 53 55 49 5i 53 55 57J 5i 53 55 57 59 Tile Biscuit and Granite Biscuit. Parian Biscuit and Glazed Bricks. China Biscuit and Salt Glaze. " n Hard Paste Porcelain. Hard Paste Porcelain. Refractory Products. Research Work. Research Work. The Series marked * can be supplied promptly, but others can only be had by.ordering a quantity of say five gross. 1-29 II_39 3I_59 590—1270° C. 890—1470° C. 1310—1870° C. 1094—2318° F. 1634—2678° F. 2390—3398° F. 3/- 3/- 3/9 each. 5496 5495- Pyrometers or Heat Indicators, for flues, stoves, etc. Dial 7 in. diam., tube 3 ft lone indicated to 2000°, 1500°, or 700° F., as required . . . . . . 3 °a?h 54%T PSS7tari£,I%h In?fic1at°r8' ** !?dicatine the temperature of bakers' ovens, etc. IJial 4 in. diam., tube 3 ft. long, marked up to 700° F. .. each i497- Pyrometers or Heat Indicators, as No. 5396, but dial 7 in. diam each 54981 P CTS % flHCat I?dif tors.' <* No- 5396, but screwed | gas, and fitted with lock nut instead of flange, for fixing in oven front . . . . each 5499- Pyrometers or Heat Indicators, as No. 5398, but dial 7 in. diam. 500- Iron Box and Tube for protecting Pyrometer Stem, for use with Fig. No. 5496 5501- Iron Box and Tube for No. 5497 '~^11 pyrometers are tested and adjusted in furnace, which has been specially made lor this purpose. £3 10 0 £1 10 £2 5 £1 15 £2 10 £0 5 £0 7 0 0 0 0 0 6 ^MICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. Thermo-Electric Pyrometers. couple." *In practice they must frequently *yw» way to the galvanometer. i&iSS^SS^^ the galvanometer to the thermo- ^In industrial work the galvanometer is of a robust type ge nerall> -ailed I the " indicator " or - recorder/- the scale of which is arranged to read or record directly in degrees of temper. Micator A thermo-electric pyrometer outfit therefore usually ^$^%g^i?$g$£Sg& or recorder, (2) the thermo-couple, (3) the connecting ^-^^^^/^ below detailed information about relation to the particular use for which the pyrometer is euired ana our instruments under these three headings. 5502 5503 5502* Portable Thermo-Electric Pyrometer. This type is supplied with scale graduated for three different temperatures. (!) o — 10000 C. for use with platinum and platinum iridium couple. (2) o — 1400° C. „ platinum and platinum rhodium couple. (3) o — 500° C. „ copper constantin couple. In this instrument the moving coil is pivoted and thus the instrument is robust and requires no skill to use and does not require careful levelling. The Indicator has a high internal resistance, and therefore the length of the leads used has within wide limits no effect on the reading. The scales are unusually clear and are divided in 10 degrees throughout their entire length. A mirror is fitted behind the pointer to enable the observer to avoid errors due to parallox (either range can be supplied). Price, without couple or couple wire 5503T Wall Type Thermo-Electric Pyrometer or millivoltmeter, made exactly similar to the above, but recommended for permanent installations. Price, without couple or couple wire If either of the above instruments are fitted with double scales so that they can be used with either a platinum, platinum-rhodium or iridium couple and the Fery radiation pyrometer, the extra charge will be JEa. £9 18 CROSS STREET • HATTCHSr GARDE1ST, E- 994 BAIRD &TATLOCK (LONDON) LTD. 5504-55C5 Pyrometer for giving continuous records of temperature. iis instrument consists of a moving coil galvanometer in which the • This instrument consists of a moving coil galvanometer in which the pointer is automatically depressed by clockwork every minute. This forces an inked thread on to the chart and thus gives a permanent record of the temperature in the form of a dot on the chart. As the pointer is depressed every r minute (or 30 seconds if preferred) and the drum carrying the chart is slowly rotating, these dots merge into one continuous line. Usually the drum is arranged to make one revolution in 25 hours, though by means of a simple change-speed arrangement it can also be made to revolve once in 2 hours 5 minutes. The usual temperature ranges are o — 1000° C. when used with platinum, platinum-indium couples, and o — 1400° C. when used with platinum, platinum-rhodium couples. The record sheet reproduced illustrates the former of these two sheets and shows the type of record obtained with a Thread Recorder under Works conditions. The instrument is fitted with a glass front so that at any moment the actual temperature at the time, and for the past few hours, can be seen at a glance. We also make a " Double Thread Recorder," so called because it can be used with two thermo-couples to give two records on the same chart. In the double instrument two galvanometers are arranged side by side in the one case and the chart is of double the usual width so that two entirely independent and continuous records are obtained. Where a customer intends to install two or more thermo-couples it is cheaper to install double recorders than single ones. 5504T Single Thread Recorder adjusted for any standard range and complete with 100 charts. Drum rotates once in 25 hours or by a simple change-speed arrangement once in 2 hours 5 minutes. Price without couple £29 0 0 5505T Double Thread Recorder giving two independent records on a single chart of double width, 100 standard charts included. Drum rotates once in 25 hours or 2 hours 5 minutes. * Price without couple . . . . . . . . . . . . . . . . £42 0 0 5506T Spare Charts for use with Single Thread Recorder . . . . . . per 100 £040 55071 „ „ „ Double Thread Recorder .. .. .. „ £050 Please specify the range of chart required when ordering. in CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 995 3 s I 52?^" _ BAIRD &TATLOCK (LONDON) LTD. 5508 Peake's Patent Control Boards (Peake's Patent). Specially recommended for use with the recorder above, as by means of this instrument the zero can be set at any temperature up to 500" C., and the range made 250° C. across the scale. This makes for a far more open scale and renders the record far more accurate as the smallest differences are easily shown on the open scale. The combination of the Control Board with the recording pyrometer give readings accurate to within 3 or 4° C. at 1000* C A small 6- volt accumulator most be used with the Control Board, which is practically a very special form of potentiometer, but the connections of this with the standard cell contained within the board are such that variations in the voltage of the accumulator do not affect the accuracy of the readings. Bulges. The Control Boards are made to give a range of 25O°C. across the recorder chart in the case of platinum, platinum-indium, and 300° C. in the case of platinum, platinum-rhodium couples. In either case the «ero can be made any value desired by simply changing the " Range Coil." Several of these coils giving difierent ranges across the scale, for example 500 — 750° C, 600 — 850° C., 700 — 950° C., may be supplied with one Scale Control Board. 55081 Peake's Patent Scale Control Board for use with Single Thread Recorder and adjusted for any one standard temperature range . . 5509* Extra Range Coil to give an additional standard range 55101 Peake's Patent Scale Control Board for use with Double Thread Recorder and adjusted for any standard range on either side of the recorder N.B. — Extra Range Coils can be supplied as listed under No. 5509 it being understood that one is required for each side of the double recorder. 551 11 Smal. 6-volt Accumulator. Suitable for use with the above boards. (Only one is required for a double or for a single board) SAMPLE THERMO-ELECTRIC PYROMETER OUTFITS. 5512* Portable Outfit, for general test work. One Portable Pyrometer, range o — 1000° C. (No. 5502) One platinum, platinum-indium thermo-couple, in porcelain tube 25 in lone with removable steel sheath (No. 5518) Four yards of Peake's Patent Compensating Leads (No. 5562) protected by flexible steel sheathing and fitted with tangs at both ends £13 3 0 £1 10 0 £18 8 0 £2 12 6 £8 16 0 £6 16 0 £0 14 0 £16 6 0 14 • CROSS STREET - HATTOIST GARDEN E-C ? BAIRD &TATLOCK: (LONDON) LTD. 5513T Permanent Indicating Outfit for use with six annealing or other furnaces. (By means of the switchboard any one of a number of couples may be switched on to the indicator.) One Wall Type Pyrometer, range o — 1000° C. (No. 5503) .. .. £918 0 One Standard lo-way thermo-couple switchboard (No. 5571) .. .. .. £2 12 6 Six platinum, platinum-iridium thermo-couples, commercial pattern (No. 5516) each, £3 19 0 ; £23 14 0 Say 60 yards of Peake's Patent Compensating Leads, either No. 5561 or No. 596 I, per yard, 1/9 ; £550 £41 9 6 Approximate weight of outfit 80 Ibs. if supplied with leads No. 5563. 50 Ibs. „ „ No. 5561. Short lengths of asbestos-covered leads and junction boxes may be included in this outfit as indicated in outfit No. 5514. 5514r Continuous Recording Outfit for use with two furnaces. One Recording Pyrometer, range of each side o — 1000° C., 100 charts of this range included. No. 5505 . . ..... . . . . . . . . £42 0 0 Two platinum, platinum-iridium thermo-couples, commercial pattern (No. 5518) "HeadB" .. .. .. .. .. each, £6 16 0; £1312 0 Two wall type junction boxes . . each, 9/6; £0 19 0 £0 16 0 £200 £59 7 0 Two lengths of Peake's Patent Compensating Lead, asbestos-covered and protected by flexible steel sheathing (No. 5564). Each length 2 yards long for connecting from couple to junction box Say 20 yards of Peake's Patent Compensating Leads, either No. 5561 or No. 5563, per yard, 2/- ; Approximate weight of outfit no Ibs. if supplied with leads No. 5563. „ „ 100 Ibs. „ „ No. 5561. >15T Continuous Recording Outfit for use with two furnaces, the records to be on a very open scale and to a high degree of accuracy. Complete outfit as already listed above . . . . . . . . . . £59 7 0 One Peake's Patent Scale Control Board, double pattern, say to make range of each side of recorder 500 — 750° C. (No. 5510) . . . . . . . . . . £18 8 0 Two spare Range Coils to make range of each side of recorder 700 — 950° C. (No. 5509) £300 One small 6-volt accumulator (No. 5511) . . . . . . . . ..£2126 Two yards of flexible connecting leads to connect accumulator to board. Fitted with tangs at both ends . . . . . . . . . . ..£050 £83 12 6 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. Boxwood Head FWelain Tub* Porcelain Hetd .FbrcelainTube 3 30 to ,1650m. Fig. A. Laboratory Fig. B. Thermo-couple pattern thermo-couple. in porcelain tube. Fig. c. A method of in- stalling thermo-couples. Fig. D. Commercial pattern thermo-couple. Fig. E. Bent thermo-couple in steam-pipe. (In this illustration the cast- iron cap which covers and protects the terminals is shown removed.) Thermo-Electric Couples. For temperatures below 500° C. copper, constantan generally employed and these are usually protected by steel tubes. For higher temperatures it is advisable to use one of the platinum series of thermo-couples which are always protected by porcelain tubes glazed on the outside to prevent gases from coming into contact with and deteriorating the platinum wires. For laboratory work, and in all cases where the temperature is greater than about 750° C., this porcelain tube is the only protection, but for commercial work when the temperature is below about 750° C., a steel protecting sheath is often used outside the porcelain tube. (Prices liable to alteration according to market price of platinum.) CROSS STREET • HATTOTST GARDEN, 998 BAIRD &.TATLOCK (LONDON) LTD. Length of Platinum, Platinum- Platinum, Platinum- porcelain tube. Iridium. Rhodium. Type. Spare inches. mm. Catalogue No. Price. Catalogue No. Price. Steel Sheath. Commercial Pattern, with re- / {. s. d. £ S. d. S. d. movable steel sheath. II 280 5516* 3 19 0 5529* 440 8 0 See Fig. D. 16 410 5517* 500 5530* 570 9 0 N.B. The length of porcelain tube is I 25 630 5518' 6 16 0 5531* 720 9 6 measured from below the bottom flange "\ on the metal head. Please state whether " Head A " (See 37 49 940 1240 5519* 5520* 8 16 0 11 6 0 5532* 5533* 9 11 0 12 2 0 11 0 12 6 Figure of Portable Pyrometer) or 57 1450 5521* 13 5 0 5534* 14 14 0 14 0 " Head B " (Fig. D) is wanted. \ In Porcelain Tubes only. Com- 13 330 5522* 380 5535* 3 14 0 plete with terminal heads as 27 690 5523* 6-00 5536* 6 11 0 illustrated by Fig. B. 39 IOOO 5524* 840 5537* 8 18 0 5i 1300 5525* 10 10 0 5538* 11 6 0 V 59 1500 5526* 12 8 0 5539* 13 7 0 Laboratory Pattern. See Fig. C. 12 300 5527* 330 5540* 360 Bare Thermo-couples, threaded with small porce- lain insulators and mica washers but no terminals or protecting tubes. Wire 0.5 mm. diam. Price is per foot run of the complete couple 5528* 1 8 0 5541* 1 11 0 Intermediate sizes charged for at a slightly higher rate. 5542* Adjustable Stop -flange for use on the steel sheaths of commercial pattern couples, for altering the depth of immersion in the furnace . . . . . . . . each Spare Porcelain Tubes (closed at one end). (The dimensions given are approximate only.) £030 Length of tube. Diameter in mm. Catalogue No. Price. inches. mm. Internal. External. £ s. d.. 5543* 12 30O 4 7 5 0 5544* 13 330 ii 14 7 0 5545* 13 330 16 20 8 0 5546* 18 450 16 20 10 6 5547* 27 700 16 20 17 6 5548* 39 IOOO 16 2O 1 1 0 5549* 5i 1300 16 2O 190 5550* 59 1500 16 2O 1 14 0 5551* 67 1700 16 2O 1 17 0 5552* Small Porcelain Sleeve Insulators, single bore, for threading on to thermo-couple wires. From 65 to 75 mm. long, 3 mm. diam., i mm. bore . . . . . . per doz. £016 5553* Mica Washers for threading on to the thermo-couple leads. Please state for what size of tube required . . . . . . . . per box £026 5554* Cement for fixing porcelain tubes in position . . . . . . . . per Ib. £006 ICHEMICAL, AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- =g3ft5 999 BAIRD &L TATLOCK (LONDON) LTD. £220 Thermo -Electric Couples, copper constantan. In steel tubes with terminal heads. For use up to 500° C. (Exactly similar to Fig. B but with steel instead of porcelain tubes.) 5555T Length of steel tube, 13 inches (330 millimetres) . . 5556T „ ,, 27 ,, (690 „ ) . . 5557r „ „ 39 „ (1000 „ ) . . 5558T „ ,, 51 ,, (1300 ,/ ) .. 5559T „ „ 66 „ (1680 „ ) .. 5560T Steam-pipe pattern copper, constantan thermo-couple. With bent stem as in Fig. 9, screwed with a J in. gas-thread for screwing directly into steam-pipes, boilers, etc. The stem projects about 3 in. into the main so that it can be used with any pipe over 4 in. internal diameter Connecting Leads. General. — For connecting from the thermo-couple to the millivoltmeter two connecting wires or " leads " are necessary, and lor this purpose it has been customary to use a single " twin-core " cable containing two insulated copper wires. With a thermo-electric pyrometer as already described and using such leads the temperature actually indicated is the difference in temperature between the hot end and the cold end or terminal head of the thermo-couple. Therefore, as the temperature at the cold end of the couple varies, the readings will vary, although the temperature of the hot end may remain constant. This makes it necessary either (i) to make provision for keeping the temperature at the cold end of the couple constant, or (2) to apply corrections to the readings as this temperature varies, or (3) to neglect the point and put up with the inaccuracy thus introduced into the readings. To get over all these difficulties we have introduced our Peake's Patent Compensating Leads. Peake's Patent Compensating Leads. — These leads are intended for use with the platinum series of thermo- couples and are made up in the form of a " twin-core " cable, one wire of which is copper and the other a special low resistance alloy. By their use the " cold-junction " of the thermo-couple is transferred from the couple to the indicator or recorder and changes in temperature at the terminals of the couple do not affect the readings in the slightest degree. The reason for this is that the thermal electromotive-force given by copper against the special alloy is the same as that given by platinum against the platinum alloy used in the thermo-couple. Experiments show that this compensation is correct for any temperature of the thermo-couple terminals up to 300° C. The usefulness of these leads is at once apparent. The fact that the temperature of the head of the pyro- meter itself — within the limit of 300° C. — does not affect the readings of the pyrometer at once obviates the necessity of water-cooled heads with all their attendant disadvantages and also allows of the employment of shorter pyrometers. Another very real advantage is the fact that pyrometers may now be inserted vertically through the roof of a furnace when formerly they had to be used horizontally because, in the vertical position, the heads would have been overheated and thus serious errors would have been introduced. The leads used with couples of platinum, platinuhi 10% indium, are, of course, slightly different from those used with platinum, platinum 10% rhodium, and, when ordering leads only, customers should state with what type of couple they are to be used. The leads have the same resistance per yard as our ordinary copper leads and can therefore be installed to replace existing leads, the only point to be noticed being that the alloy wire which is the thicker of the two must be connected to the platinum or — terminal of the thermo-couple, whilst the copper wire, which is the thinner one and is covered with red insulation, must be connected to the platinum alloy or + terminal. Peake's Compensating Leads. 5561T Flexible braided pattern, for general use . . . . 2/- 5562T „ „ „ but enclosed in flexible steel sheathing, to stand rough usage .. .. .. .. 3/- 5563T Lead-covered pattern, for permanent installations where moisture may be present . . . . . . . . 2/- 5564T Asbestos covered pattern, in flexible steel sheathing, for use in hot positions . . . . . . . . . . 4;. For fitting coloured tangs on both ends of any of the above leads add 3/-, or on one end only, 1/6. Ordinary Copper Leads. 55651 Braided and compounded pattern, twin core . . . . . . per yard £008 5566T Lead-covered pattern, twin core .... £008 1000 BAIRD &TATLOCK (LONDON) LTD. Copper, Constantan Leads. These leads are made up as a twin-core cable, one wire being copper and the other constantan. When used with copper, constantan thermo-couples they transfer the " cold-junction " from the thermo-couple to the indicator, just as the compensating leads already described do in the case of platinum thermo-couples. 5567T Flexible braided pattern, twin-core copper, constantan cable . . . . . . per yard 5568T „ „ „ but enclosed in flexible steel sheathing, to stand rough usage per yard 5569T Lead covered twin-core copper, constantan cable . . . . . . „ Switch Boards, intended for installations where more than one thermo-couple is used on the one indicator. 5570T For four thermo-couples . . . . 5571* „ ten PLATINUM RESISTANCE PYROMETERS (2). Platinum Resistance Pyrometers are the most accurate form of instrument for recording temperatures between o — 1000° C., the readings being very open, so that temperatures can easily be read to i° C. A complete platinum resistance pyrometer outfit consists of a suitable indicating or recording instrument connected by leads to the pyrometer itself. The essential part of this latter is a coil of fine platinum wire — generally called the bulb — which must be protected from damage by a suitable protecting tube. This tube may consist of brass or steel for moderate temperatures but must be of porcelain or quartz for high tempera- tures. The coil of wire varies in electrical resistance with its temperature, and therefore the indicator, which is simply a resistance measuring instrument, can be calibrated to read directly in terms of the temperature of the platinum coil. The bulb measures about J in. diameter by 2 in. long in our standard instrument, and is connected by platinum lead wires to the terminals at the top of the protecting tube. When the protecting tube or stem will not be subjected to any considerable temperature copper lead wires may be used inside it instead of platinum. ' • 5572-5573 5572T Whipple Temperature Indicator, - 10 to 1+200° C., graduated every i° C. In teak case without couple or leads 5573T Ditto, range o° to 2200° Fahrenheit, graduated each i° F., without couple or leads This instrument must be connected to the couple by means of 4-way leads, which may be of any length desired. To take a reading with it the key F is pressed and the movement of the pointer B observed. The pointer will be deflected one way or the other but by turning the handle H in the corresponding direction the pointer can be brought back to its zero position in the centre of the window. When this is the case the temperature can be read off directly from the scale in the window A. The scale is extremely open, being divided every t° C. on the standard temperature scale from - 10 to + 1200° C. The necessary current is obtained from the two dry cells c, so that the instrument is entirely self contained. £0 1 3 £0 £0 £2 £2 7 12 £21 £21 0 0 1001 BAIRD &. TATLOCK (LONDON) LTD. 5574-5583 Callendar's Recording Pyrometer. This instrument is based on the Wheatstone's bridge principle, but instead of the bridge having to be balanced by hand adjustments, it is done automatically by the recorder itself. The contact which slides to and fro on the bridge wire BW carries a pen which writes on a drum. The movement of the pen is controlled by two clocks which in turn are controlled by electro-magnets. The galvanometer pointer carries two insulated wires which can make contact on one side or the other of a platinum tipped contact wheel. When the pen is indicating the correct temperature these contacts do not touch the-wheel, but if the temperature changes one or other of the contacts is made causing one electro-magnet to release its clock and draw the pen carriage along the bridge wire until the balanced condition is again restored. A 4-volt accumulator is necessary to operate the recorder. 5574r Price, adjusted for one particular range of temperature. Drum rotating once in 25 hours also 2 hours 5 minutes. Including 100 standard charts . . . . . . . . £37 15 0 5575T Ditto, but with Wayne's Continuous Paper Movement to give a record extending over one week . . . . . . . . . . . . . . . . . . £41 0 0 5576T Zero Coil, to enable the zero of the above recorders to be raised (e.g. a coil may be supplied to alter the range 0—1000° F. to 700—1800° F.) . . . . . . . . . . £0156 5577r Gallendar Recorder with range across scale 100 or 200° C. Fitted with switchboard to enable the zero value to be made any temperature desired in steps of 50° C. Drum rotating in 25 hours or 2 hours 5 minutes .. .. .. .. .. .. £40 10 0 5578T Ditto, but with drum rotating once in 12 hours or once in i hour . . . . . . £40 10 0 5579T Ditto, but with Wayne's Continuous Paper Movement to give a record extending over one week . . . . . . . . . . . . £43 10 0 Dust-tight cupboard for recorder. Fitted with glass door . . . . . . . . £2 18 0 Spare 25-hour Charts. Almost any range . . . . . . . . . . per 100 £050 Spare 7-day Charts for recorders 1071 and iogt . . . . . . . . per 25 £050 £0 11 0 5580T 5581* 5582* 5583T Repair Outfit for any of the above recorders, including soldering iron, solder, phosphor-bronze strip, and fine silver wire, also camel's-hair brush . . 14 • CROSS STREET • HATTOTST GARDETST, E-C 1002 0 BAIRD &.TATLOCK (LONDON) LTD. •««^» ., £990 £0 13 0 £31 2 0 £37 15 0 £5 15 0 SAMPLE RESISTANCE PYROMETER OUTFITS. The following are given as samples of some usual resistance pyrometer outfits. It will be understood that many different combinations can be made, and we are always pleased to submit detailed quotations for outfits to suit inquirers' special conditions. 5584T Portable Indicating Outfit, for general test work such as measurement of temperatures in furnaces, flues, etc. Extremely useful as a standard of reference. One Whipple Temperature Indicator, -10 to + 1200° C., in case complete (No. 5572) £21 00 One Platinum Resistance Pyrometer, commercial pattern, 25 in. long (No. 5594), Type " A " ...... Four yards of 4-way leads in flexible steel sheathing and fitted with tangs at both ends Approximate weight of outfit 33 Ibs. 5585T Recording Outfit for use with Annealing Oven. One Callendar Recorder, almost any range, including 100 charts. No. 5574 One Platinum Resistance Pyrometer, commercial pattern, n in. long, No. 5594, Type "B" .. .. .. .. .. : Two yards of asbestos-covered cable in flexible steel sheathing, to connect from the pyrometer to a junction box. No. 5599 at 3/- per yard One wall type junction box Twenty yards of lead-covered cable to connect from the junction box to recorder, No. 5597 at lOd. per yard Approximate weight of outfit 90 Ibs. 5586T Recording Outfit for Laboratory Use, taking recalescence curves, etc. One Callendar Recorder with range adjustable, No. 5577 One Laboratory Pattern Resistance Pyrometer, No. 5591 . . ... Four yards of flexible cable with tangs at both ends, No. 5596 Approximate weight of outfit 58 Ibs. 5587r Accessories for Outfits Nos. 5585 and 5586. Two Four-volt Accumulators, for use with recorder (one to be re-charged whilst the other is in use) . . . . . . . . . . . . each, £2 12 6 ; One Small Voltmeter, o — 5 volts, for use with accumulators, in case complete One Special Hydrometer for testing the acid of the closed accumulators Two yards of flexible lead with tangs at both ends for connecting the recorder to the accumulator . . . . . . . . Approximate weight of outfit 65 Ibs. £0 6 6 £0 9 6 £0 16 8 £45 2 8 £4) 10 0 £6 16 0 £0 9 0 £47 15 0 £5 5 0 £1 2 0 £0 11 0 £0 4 6 £7 2 6 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. He»d 1r Porcelain Head ^/PorcelainTuba -4PlahrmmLeads /Mica Discs -Platinum Coil £2 12 6 £2 15 0 £550 £6 16 0 Fig. A. Fig. B. Fig. C. Resistance Thermometer Larger size Resistance Commercial pattern in glass tube. Pyrometer in steel tute. Resistance Pyrometer. Platinum Resistance Couples for use with Whiffle Indicator or Callendar Recorder. All prices are subject to market fluctuation in the price of platinum. 5588T Laboratory Pattern in Glass Tube. See Fig. A. For use up to 300° C. Length 13 inches (330 mm.) 5589T Laboratory Pattern in Porcelain Tube. Otherwise similar to Fig. A. For use up to 500° C. Length 13 inches (330 mm.) 5590T Ditto, but with platinum leads. For use up to 1200° C. 5591T Ditto, as in Fig. A, but fitted with porcelain tube 16 inches (400 mm.) long 5592T Steel Tube Pattern with leads of copper for temperatures up to 500° C. See Fig. B. Length . . 13 27 39 51 60 Price . . £270 £2 10 6 £2 15 0 £2 19 0 £330 each. 5593T Porcelain Tube Pattern, as Fig. B, but with porcelain tube and platinum leads. Length . . 13 27 39 51 59 inches. Price .. £5 5 0 £8 18 0 £12 2 0 £15 10 0 £17 12 0 each. 55941 Commercial Pattern in Porcelain Tubes with steel sheaths and platinum leads, supplied in two patterns. Type A or type C as above at the same price. Length below flange . . . . n Price .. .. .. £5 15 0 £7 Length below flange . . . . 37 Price £12 18 0 £16 55951 Spare Flanged Steel Sheaths for above couples. Price .. 8/- 9/- 9/6 inches. 0 0 £9 £18 0 0 inches, each, inches, each. ll/- 12/6 14/. each. Spare Porcelain Tubes, etc., for above, see page 999, under Accessories for Thermo-Electric Pyrometers. CROSS STREET • HATTOTST GARDEN, E-C 1004 BAIBD &TMXOCK. (LONDON) LTD. Connecting Leads for use with Platinum Resistance Pyrometers. 5596T Flexible Cable (4-way), indiarubber and double cotton-covered . . . . per yard 5597T Lead -covered Cable (4-way), for permanent installations per yard, lOd. ; per 100 yards 5598T Asbestos -covered Cable in Flexible Steel Sheathing (4-way). Has an inner insulation of rubber . . . . . . . . . . . . . . . . per yard 5599* Asbestos -covered Cable in Flexible Copper Sheathing . . . . . . ,, 5600r Stout Insulated Cable in Flexible Steel Sheathing (4-way) 5601T Spirally-armoured Cable (4-way). Is protected by an open-wound spiral of steel wire per yard 5602r Heavy Armoured Cable (4-way). Insulated with pure and vulcanised rubber, lead- covered, braided, armoured with galvanised iron wire, braided and compounded per yard, 2/4 ; per 100 yards Any of the above can be fitted with tangs at both ends for an extra charge of 5/- ; or at one end only, 2/6. FERY RADIATION PYROMETERS. The Fery Radiation Pyrometers are made in two patterns, both of which are operated by radiant heat. The sensitive element in the instrument varies, however, being in the one case a small thermo-couple and in the other case a small bi-metallic spiral. To distinguish clearly between the two types we have designated them as follows : (1) The Fery Radiation Pyrometer. (2) The Fery Spiral Pyrometer. The first of these is the more accurate instrument and has the advantage that it can be used with a recorder if desired, whilst the Spiral Pyrometer is cheaper and more compact. These instruments are made in three standard ranges : 500 — 1100° C. 600 — 1400° C. 800 — 1700° C. This Pyrometer consists of a telescope mounted on a tripod and connected by leads to one of our standard pivoted coil millivoltmeters (see Nos. i and 2). The heat rays from the furnace are received on a concave mirror and brought to a focus. Looking through the eyepiece the observer sees this image of the furnace in the small mirror, and by means of a special device, is able to point the telescope on the exact spot whose temperature is required and to focus it on that spot. The small sensitive thermo-couple, which is situated just behind a small hole in the mirror, is therefore heated and delivers current to the millivoltmeter, which may be calibrated to read directly the temperature of the body at which the telescope is pointing. £0 £3 £0 £0 £0 0 0 3 3 £0 0 10 £10 0 0 Taking the temperature of a gas retort with a Fery Radiation, Pyrometer. 5603 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. 5603' Fery Radiation Pyrometer, complete with National Portable outfit consisting of Fery telescope wooden tripod, 4 steel sheathing, portable millivoltmeter calibrated 600 to 1400 ., and The above Pyrometers are specially suited for temperature measurements in connection with the heat treatment of iron and steel. The Fery Radiation Pyrometer is also suitable for use in conjunction with the Recorder No. 3, which is substituted in place of the millivoltmeter. 5604' Recording Fery Pyrometer Outfit, as used in connection with malleable iron or case-hardening furnaces. Fery Radiation Pyrometer, telescope only, No. 5603 Protecting Cover for above, fitted with lock and key, and including two clamps and horizontal supporting bar . . Single Thread Recorder with drum rotating once in 25 hours. Range across chart o — 1050° C. 100 charts included. No. 5504 Thirty yards of 2 -way spirally armoured leads for connecting from telescope to recorder, at 8d. per yard plus 4/- for fitting tangs at both ends . . Blind Fireclay Tube 4^ in. internal diameter and 4 ft. long. For building into the furnace wall Outfit complete 56051 Outfit as above but with millivoltmeter, wall type instead of recorder . . £26 5 0 £12 12 0 £300 £29 0 0 £140 £0 16 0 £46 12 0 £27 10 0 Fig. A. Front view of the Fery Spiral Pyrometer showing scale and pointer. 5606 Fig. B. The Fery Spiral Pyrometer on its tripod. 5606T Fery Spiral Pyrometer, complete with National Physical Laboratory Certificate. Tripod and travelling case included. Range 600 to 1400° C. . . . . . . £18 The Fery Spiral Pyrometer is a simple and more compact instrument, though less accurate than the radiation type. The method of receiving and focussing the radiant heat is, however, the same. The difference consists in the sensitive element, as instead of using a thermo-couple which must be connected to a millivoltmeter, a small trimetallic spiral is used, and this controls the movement of a pointer, which move across a dial calibrated in temperature degrees. The instrument is thus entirely self-contained. This pyrometer is most suited for taking the temperature of gas retorts, pottery kilns, glass furnaces, etc., where the highest accuracy is not required. 8 0 CROSS STREET • HATTOTST GARDETST, E-C 1006 BAIRD &TATLOCK (LONDON) LTD. SECTION No. 18. 5607-5608 5607' Simmance-Abady Calorimeter (patent) is the English Standard Gas Calorimeter, and can be used with equal convenience and accuracy with any kind of gas. Constancy of water flow is ensured. Constancy of gas flow is ensured. Loss by radiation absolutely safe- guarded. The reduction of the products to proper temperature is made an easy matter. The flame is visible throughout a test. A test of absolute accuracy is made in less than one minute. Very moderate in price. Specification. — Apparatus to right of line in illustration, consisting of calorimeter, in sheet copper and brass, with water level tube, adjustable shutter for regulating products of combustion, water jacket — -asbestos covering and wood lagging absolutely prevent absorption or radiation. Filling bucket for transfer of water from waste to measure without affecting its flow ; thermometers placed side by side. Improved stand with spout for condenser products. Composite air burner fitted with mirror by which flame is visible throughout test. Three open scale thermometers in Centigrade degrees divided into tenths, two graduated glass measures, set of printed instructions. Price as above £10 18 6 5608T Apparatus as above, together with special accurate wet meter, governor of the balance type and connection mounted on convenient stand, the whole as illustrated. Price complete Instructions on page 1008. £19 17 6 1007 BAIRD &TATLOCK (LONDON) LTD. Brief Instructions for Simmance-Abady Calorimeters, No. 5607-5608. Let water flow and gas burn, regulate outlet shutter until the temperature indicated on outlet products thermometer shows that all the heat has been extracted, the water meanwhile running to waste. Observe the thermometers, which after a few minutes will become steady, then observe pointer of gas meter, and when it passes any marked point, direct the water (by means of the tilting bucket) into the empty measuring vessel : wait until the pointer of meter passes another marked point, and then release bucket. Observe difference between the cold and warm water thermometers, note quantity of gas passed and water measured, then if gas «« n, water — m, and difference in thermometers t the calorific power equals — t. If the measurement of gas has been in litres, result = calories per litre. If the measurement of gas has been in cubic feet, result — calories per cubic foot; To convert this latter to B.Th.U.'s, multiply by 3.97. A list of gas companies, technical schools, scientists, manufacturers, and Governments using the calorimeter sent on application. A certificate of accuracy signed by Simmance & Abady accompanies each instrument. 5609 5609' The Simmance-Abady Patent Calorimeter for testing the calorific power of light oils spirits, etc. By means of the apparatus provided, this can be carried out as a very exact test The balance used is extremely sens,tive, and the number of B.Th. units which can be developed from each sample of oU are ascertained with facility, and thus information obtained in a department in which practicaUy n TworThas hiSierto been done. The results are actual and absolute, and are not theoretical. The principle of the calorimeter is the same as that used for gas purposes (see No. 5607) The arransement as shown makes the method used in oil testing sufficiently clear, but instructions are furnished with each Tapp^tus The results are obtained in B.Th.U.'s or calories per grain, gramme, or litre of oil. * "^ f°r g&S W°rk> " the laboratory is Provi<^ with the necessary gas Price complete as illustrated £21 0 0 1008 BAIRD &TATLOCK. (LONDON) LTD. I 5 5610-5611 5610* Boy's Calorimeter. This Calorimeter is the one specified by the Metropolitan Gas Referees in testing London gas, and while it is not recommended for use where an experimentalist might be called upon to test Producer Gas or Water Gas, j well as Coal Gas, it has the advantage that the portion exposed to products of combustion can be placed in a sssel and neutralised by an alkaline solution. It consists of Combustion and Absorption Chamber with burner, verflow funnel for attachment to wall, change over bucket, two normal thermometers reading to 50° C. in jVtns. and one thermometer for outlet products, one large measuring vessel, one small measuring vessel, two reading lenses for thermometers ; in fact all the apparatus to the left of line A in Fig. 5610-5611. Price complete 561 1T Boy's Calorimeter, as above, but with special wet meter, balances, governor, and all con- nections arranged on convenient stand. The whole as the complete illustration above. Price complete £12 10 0 £21 9 0 I 1009 BAIRD &.TATLOCK (LONDON) LTD. 5612 Simmance & Abady's Patent Recording Calorimeter (Calor-graph). This instrument (Fig. 5612) automatically records on a chart the calorific power of any gas in heat units. The gas passes through a pressure governor and then through a governor which is actuated by changes in specific gravity. It therefore maintains a gas flame consuming the same volume of gas per hour whatever the change in composition. The heat of combustion of this constant flame varies according to the calorific power and operates a recording thermometer (differential), the pen of which marks on a chart graduating in B.T.U., per cubic foot or calories per cubic metre, said chart being made to revolve by clockwork. The Differential Thermometer is com- posed of opposing diaphragms lined throughout with a plating of palladium hermetrically sealed and containing air under pressure. They are made differential so as to set up an automatic correction for changes in atmospheric temperature and pressure. The Calorimeter thus possesses the following advantages. (a) It is made in ranges suitable for any gas. (6) It requires no water nor dees it utilise any uncertain expansion of metal or other principles which involve empirical adjustment. Its results are automatically reduced to N.T.P. (c) No meter, pendulum or other devices used ; there are no water levels to adjust. It is absolutely simple, small in bulk, and it can be set up and started just as it is taken out of the packing case. (d) It has practically no moving parts, nothing to get out of order and is incorrodible. 5612* Simmance & Abady Patent Calor-graph, 80 to 300 B.Th.U.'s . . 5613T Simmance & Abady Patent Calor-graph, 380 — 600 „ 5614r Simmance & Abady Patent Calor-graph, 450 — 700 56151 Simmance & Abady Patent Calor-graph, 0—2500 cals. per cubic metre 5616T Simmance & Abady Patent Calor-graph, 2500 — 5500 „ £30 £30 £30 £30 £30 0 0 0 0 0 0 0 0 0 0! CROSS STREET • HATTOTST GARDETST, E- C BAIRD &TATLOCK (LONDON) LTD. 5617 5619 561?T Roland Wild Calorimeter, complete as illustrated, Fig. 5617, with sensitive Fahrenheit Thermometer (40 to 100° F. in ^ths) nickel wire, certificate of water value and instructions £2 17 6 5618T Roland Wild Calorimeter as No. 5617 but with electrical ignition . . . . . . £3 15 0 5619r Roland Wild Calorimeter as Fig. 5618, electrical ignition and mechanical stirrer, actuated by clockwork motor, it is fired by means of dry cells or accumulator . . . . . . £550 It may happen that the intending user has no apparatus for crushing and drying the coal and weighing the amount of coal and sodium peroxide it is necessary to place in the Calorimeter and for measuring the water to ba placed in water vessel. We therefore provide :— 5620T Roland Wild Calorimeter No. 5617 together with balance of novel design in case and made with two special weights, one for the coal and one for sodium peroxide. For drying the fuel a well-made copper oven with gas burner or spirit lamp is provided. In addition there are mortar and pestle, carrel hair brush, tweezers, watch glass, sieve, scoop, and 1,000 cubic centimetre glass water measuring vessel . . . . . . . . £600 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. 562V Set No. 5620 but with Calorimeter No. 5618, arranged for electrical firing 5622* Set No. 5620 but with Calorimeter No. 5619, arranged for electrical firing and mechanical stirring COAL TESTING SETS INCLUDING CALORIMETERS. The sets of apparatus we offer are simple, practical, accurate, and complete. 5623* Roland Wild Calorimeter with thermometer ; one sensitive balance reading to i milli- i with knife edges and planes, pan arrestment and beam support ; m glass case with levelling screws and box of weights in velvet-lined case with forceps, one Bunsen burner, one desiccator two porcelain crucibles and lid, pair crucible tongs, three watch glasses, two sieves wire for supporting crucible, copper oven with thermometer stand and burner, mortar and pestle, camel hair brush, tweezers, scoop and glass measuring vessel of 1,000 cubic centimetres capacity, complete with instructions 5624T Roland Wild Calorimeter as above, but arranged for electrical firing . . 5625T Roland Wild Calorimeter as above, but arranged for electrical firing and mechanical stirring, complete with instructions 5626T Sodium Peroxide in i Ib. tins (enough for about 36 tests) . . . . per Ib. 56271 Sodium Peroxide put up in sealed tubes each containing sufficient for i test . . Brief Description of Instructions lor Roland Wild Calorimeters. The apparatus consists (see Fig. 5617) of a combustion chamber suspended from the cover by conduit which is furnished with a valve There is a well-made copper water vessel inside an outer vessel, heavily mckelled, forming an air jacket which effectually prevents radiation and absorption, thus rendering the rise in temperature ol the water an absolutely true guide to the heat given off by the fuel. There is also provided a first quality Fahrenheit thermometer the scale being divided into ^ths, and easily read in .frtto, and an agitating paddle or stirrer. (a) Place stated amount of water into water vessel, and of dried fuel, with proper amount of sodium peroxide into the crucible, which screws firmly home. (b) Stir water until temperature is constant, and note same. Ic) Heat to redness a small piece of nickel wire, drop same through valve opening, and draw valve home ; agitate water by stirrer. (If electrically fired, this is not necessary.) Note highest temperature. The rise in temperature multiplied by 1,000 = calorific value in B.Th.U. s of the coal. The calorific value + 967 = evaporative power per Ib. of the coal. Example.— Water, 51 ; rise, 13.15 ; coal value, 13,150 B.Th.U. ; evaporative power per Ib., 13.6 (^i^). Successive tests can be made with rapidity, thus enabling good average results of a. bulk of coal to be obtained. £6 17 6 £876 £12 6 6 £13 4 0 £14 14 0 £036 £050 5628 5628* Calorimeter, designed by Wm. Thomson, F.R.S. (See Journal of the Society of Chemical Industry, 29th November, 1886.) Price with platinum crucible and delicate thermometer £4 15 0 (Price subject to alteration in price of platinum.) 5629s Glass Jar for above, marked at 2,000 grammes . . . . . . . . each £066 CROSS STREET • HATTOTST GARDEN, 1012 BAIRD &TXTLOCK (LONDON) LTD. 5630 5630' Calorimeter, Fischer's improved new form, with silver vessel, lining of platinum and silver, platinum gauze basket, steel mortar, normal thermometer o to 50° C in Whs ordinary thermometer .. (Subject to market price of platinum). Price about £15 5 0 THE APPARATUS COMPRISES— 1. The calorimeter vessel, packed in eider down, and enclosed in an oak case 2. Cover for the same carrying the stirrer and thermometer. 3 Silver combustion chamber fitted with tight cover, carrying an inlet tube D, the upper part of which ends •n a g ass T tube. The outlet is either a spiral tube or a flat second chamber with a tube^unnW parallel to ?he body from its base to the top of the apparatus, and, like the inlet, ending in a glass T tube through whtch a ther mometer is inserted to control the temperature of the escaping gas. ^ sma1' PIatinum wire basket for holding the sample to be tested is carried in a thin sheet platinum cylindrical ;ssel wl i fits on to the inlet tube of the combustion chamber by means of a tube attached to its silver cover. The sample is pressed into a cylindrical shape by means of the small steel mortar supplied, and placed in the atmum basket. The carrier is fitted to the top of combustion chamber, and the cover made air and water-tight by luting it with grease, and the chamber fastened to the base of the calorimeter by its tripod feet. The calorimeter is filled with 1,500 cubic centimetres of water, and the cover placed in position. The stirrer is now worked until the thermometer (which is divided into tenths or twentieths of a degree is also fastened to the cover) remains stationary. During this time a slow current of oxygen has been palsing he combustion chamber, and as soon as the temperature is constant, the sample is ignited either bv elec- :ity or by means of a small particle of incandescent charcoal. The current of oxygen is now increased to 2 to 4. pW per nitrate. As the combustion approaches the finish, the amount is reduced to i§ litres per minute. This three minutes, and about thirty seconds later the thermometer will be" at its maximum reading, particulars vide Zeitschrift fur Angewandte Chemie, 1892, p. 542, and Fischer 1 - xxi., 2nd edition, 1893, P- 63. ^CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1013 BAIRD &TATLOCK (LONDON) LTD. 5631 5631 Thompson's Ca'orimeter, or fuel tester. Apparatus complete, comprising ^ an iron pestle and mortar, fine mesh sieve, scales with gramme weights, box to contain " oxygen mixture," spatula, cylindrical copper furnaces, spring clutch base to carry a furna.ce, copper combustion cylinder, fitting the springs of the base, delicate thermometer, clearing wire, and graduated glass cylinder. The whole fitted into a French polished, cloth lined, mahogany case, with lock and key, and instructions Prices of Separate Parts. 5632 Jars for above . . . . . . . . . . . . . . . . each 5633 Clutch base . . . . . . . . . . . . . . . . ,, 5634 Copper furnace tubes, brazed . . . . . . . . . . . . „ 5635 „ combustion cylinder with stopcock . . . . . . . . . . ,, 5636 Thermometer, o to 35° C., in metal protecting case DR. LEWIS THOMPSON'S SOLID FUEL CALORIMETER. Solid fuels are reduced to fine powder, and two grammes of the powder are intimately mixed with nitrate and chlorate of potassium. The whole is placed in a cylindrical vessel of copper (called a furnace), and the latter placed in the socket of a metal plate, which is furnished with springs which are capable of clutching the bottom of a cylindrical copper bell, from the upper part of which extends a long pipe, closed by a cock. A fuse being applied to the top of the material in the furnace and lighted, the bell is forced down upon the springs of the base plate, and the whole immersed in a specific quantity of water which is contained in a long glass jar. Combustion presently ensues ; and the whole of the heat evolved from the burning fuel is absorbed by the water and by the apparatus. Temperatures are carefully taken before and after combustion, and the heating power of the fuel deduced from the rise in temperature. The operations are not difficult ; and, when due care is taken, the results are accurate. This apparatus is extensively employed by governmental authorities, and by some railway companies, for the purpose of ascertaining the relative commercial values of the coaJs for which they contract. £5 £0 £0 £0 1 £0 12 £0 12 CROSS STREET- HATTOIST GARDETST E-C 1014 BAIRD &.TATLOCK (LOM)ON) LTD. 5637 Rosenhain's Improved Form of Thompson Calorimeter. The advantages claimed for the Rosenhain Calorimeter are : Accuracy. — Practically complete combustion is secured, less than J % of the sample escaping combustion. I When combustion is properly regulated no carbon monoxide is formed. When burning oils the saturated pellets I burn completely and rapidly, thus avoiding the risk of some of the oil remaining unburnt in the absorbent pellet. Quickness. — A determination of the calorific value can be made in little more than half-an-hour. The com- bustion of 2 grammes of coal occupies about ten minutes. Safety. — No parts of the apparatus are exposed to high pressure, and the risk of breakage is small. Small Cost of experiment. — A comparatively small quantity of oxygen is required, and the only breakable part is a glass chimney, which can be replaced by an incandescent gas-light chimney for a few pence. Ease of observation. — As the sample burns under observation its behaviour as regards caking and clinkering can be studied. No stirring required.— The water is agitated by the gas bubbling through it. 5637T Rosenhain's Calorimeter with accessories and simple thermometer Accessories. 5638r Calorimeter with ball valve and brass vessel 5639r Coal Compressing Mortar 5640T Glass Measure, 1,000 cubic centimetres in 10 cubic centimetres 5641T Thermometer, 0-25° C. in TV C. . . 5642T Thermometer, 0-50° C. in f C. 5643T Silica Tray .... ...... £9 14 3 £6 16 6 £0 13 0 £063 £0 13 0 £029 £039 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1015 BAIRD &TATLOCK (LONDON) LTD. 5644 5644s Junker's Calorimeter, for determining the calorific power of combustible gases, fitted in travelling case with fittings, with directions Meter for above Governor „ Measure ,, Price, complete as illustrated The Junker's patent calorimeter has been in use for a large number of years in all the principal gas works in this country and abroad, and is largely used by professors in technical colleges for demonstrative work, thus proving its value. Combined with the usefulness of this instrument, one of the most important points is its simplicity. The apparatus is set up as shown in Figure herewith, and an unskilled operator can simultaneously observe thermometers, the index of the gas meter, and the measuring glasses at one time. The principle on which the apparatus acts is that the heat generated by a flame is transmitted to a current of water flowing at a constant rate, and measure- ments are taken — 1. Of the quantity of gas burned. 2. Of the quantity of water passing through the apparatus. 3. The difference in temperature of the water on entering and leaving the apparatus. The water inlet is connected to the nipple a to the centre of the upper container. This water must be kept continually flowing, and is therefore arranged accordingly so that continuous readings may be taken. After this water has passed through the calorimeter, it leaves the nipple c, and is gathered in a glass measure. In order to collect any condensed water which may take place inside the calorimeter, a drain a.td is provided. The calorimeter should be filled with water by opening the diaphragm e, and when the calorimeter is filled it will be observed to discharge at c. With the thermometers then in position the apparatus is ready for taking tests. Full description and method of working sent with each apparatus. £23 10 0 £3 10 0 £4 15 0 £0 15 0 £32 10 0 CROSS STREET • HATTCTNT GARDEN E-C 1016 BAIRD &IATLOCK. (LONDON) LTD. 5645 5645T Mahler's Bomb Calorimeter, for determining the calorific values of solids, liquids, and gases. The apparatus consists of — • Insulated outer vessel. Combustion bomb of steel, enamelled inside. Platinum capsule. Platinum electrodes. Iron wire for ignition. Stirring arrangement. Battery. Set of thermometers : 8 to 19° C. in ^°, 18 to 20° C. in -^°, 14 to 25° C. 40 ft. cylinder of oxygen, with pressure gauge and connections to bomb. The combustion takes place in a closed bomb or cylinder of steel. The substance, if solid, is placed on a small platinum capsule, and the bomb is filled with oxygen at 25 atmospheres' pressure. Ignition is produced by passing an electric current through an iron wire lying in contact with the substance. The bomb is nickel- plated outside, and is lined inside with enamel to resist the corrosive action of the nitric acid formed during the combustion. The distinguishing feature of Mahler's bomb is this layer of enamel, which replaces the more expensive platinum lining of Berthelot's apparatus. Price complete as specified above (approximately) £55 0 0 Full working instructions sent with each apparatus. Price fluctuates according to the market price of platinum. See Chemical Trade Journal, January, 1904, pp. 63-66. ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &WLOCK (LONDON) LTD. 5646 Fig. I. — The Complete Calorimeter, with Pressure Gauge, Oxygen Connections, Battery, Acid, etc. (Lid of Bomb removed, showing Crucible Holder.) 5646s Calorimeter, " The Sarco " (Mahler-Donkin Bomb System), suitable for the deter- mination of the calorific values of coal, coke, peat, liquid fuels, oils, etc., and producer gas. Go'd-plated bomb, with oxygen valve, crucible holder, and platinum wire, the outer and inner containers, together with stirring apparatus, special thermometer divided in fiftieths of a degree, the pressure gauge with valve, oxygen connections, batteries, acid, spare crucibles, and spanners £35 0 Description on page 1019. 14 • CROSS STREET • HATTCnST GARDETST, E- C 1018 RAIRD &TATLOCK (LONDON) LTD. 5646 A5646 Fig. 2. — Showing various parts in position. DESCRIPTION. of the fueSrtst is then' S^'MooS^?"8 ^ Watef "I"™'61* °f *e aPParatus- the -lorific value If w H Calculation of Results (no corrections). = weight of fuel tested in pounds, •• calorific value of fuel in British Thermal Units 'psr pound i - weight of water in calorimetric vessel in pounds, W, = water equivalent of calorimeter in pounds, t0 temperature of water in calorimeter before combustion, -A. /«r I"axlmum temperature of water in calorimeter after combustion, inen (W, + Ws) x (t, - 10) =heat received by water and instrument wH = heat evolved by combustion of fuel sample. I = (W,+W.) x (t,-t0) in British Thermal Units per pound, w ot subject to wear, it has no delicate parts likely to get out of order, ar Press, for making coal pastilles, for testing in calorimeters . . is therefore each £300 1019 BAIRD &TATLOCK (LONDON) LTD. Reg. No. (applied for). (A. SA. =>*• • ft • <2 B. Fig. 3. — Shomng Constancy oi Shape and Character of Coke obtained from each Coal. •Ill 1 IB m m is. l& 17 18 Fig. 2. — Cokes obtained from Twenty different Coals. Dr. R. Lessing's Electric Furnace for the determination of the cooking properties of coal. For description and prices see page 1021. CROSS STREET • HATTCTN GARDETST, E- C 1020 BAIRD &TATLOCK (LONDON) LTD. Electric Furnace. of coal. Fig 4. — Complete Set of Research Apparatus. 5647-5656 By Dr. R. Lessing. For the determination of the coking properties This furnace has been designed by Dr. R. Lessing to compare the Coking properties of Coal and to study carbonisation phenomena, using as a standard quantity one gramme of coal ; it consists of a silica furnace with the outer tube wound with a coil of thin platinum wire, and fitted with an inner tube of siliea or platinum into which the sample is placed ; a further tube is used as a weight to prevent the coal being blown out of the tube. The swelling properties of coal are very clearly shown by this method and it is found that coals differ very widely in the extent to which they expand during various periods of the test and after complete coking. The coke specimens, as will be seen from Fig. 2, vary in size and structure. Fig. 3 will show the constancy of shape and character of a coke obtained from each coal, and if the results are compared with those of the old crucible method, they will be found to be very striking. 5647T Electric Furnace, with resistance fitted to base for cutting down the current and for regu- lating the temperature, arranged for 220 volts direct current . . . . . . £660 5648r Electric Furnace, with resistance, etc., but arranged for no volts direct current . . £600 At the same time it is quite simple to extend the process — to observe the quantity, etc., of the tarry vapours (gases evolved during various periods of each test) — by closing the retort tube and connecting to a gas collecting system, as shown in illustration No. 4. The ammeter and millivoltmeter being simply used in standardising, the instruments are not as a rule required. For carrying out experiments in connecting the tar products the following extras may be required : — 5649T Retort Tube, with addition as shown in illustration, made in silica, with glass gauge tube £076 5650r Tar Scrubber and Purifier . . . . . . . . . . . . ..£016 5651T Gas Measuring Tube (nitrometer) and Aspirator with I.R. tubing . . . . . . £0136 5652T Millivoltmeter, 0-120 . . . . . . . . . . . . . . ..£4100 5653T Ammeter, 0-5 in ^th . . . . . . . . . . . . . . . . £1 12 6 5654T Kipp Apparatus, 4 in. . . . . . . . . . . . . ..£096 5655T Wash Bottle, 16 oz. . . . . . . . . . . . . . . ..£026 5656* Stand with Clamps, etc. . . . . . . . . . . . . . . . . £0 12 6 For detailed description of procedure, see Journ. Soc. Chem, Ind., 1912, vol. xxxi., p. 465 ; and Journ. o/ Gas Lighting, 1912, vol. cxviii., p. 855. 1021 K^IST - — BAIRD &TATLOCK. (LONDON) LTD. 5658 5658T Hempel's Calorimeter, consisting of iron autoclave with cover and valve, platinum wire with hook, terminal and four fireclay dishes, one spanner, three keys, cast-iron cylindrical base with four wood screws, one manometer with connecting tube, one retort with connecting tube for the preparation of oxygen, one nickel-plated brass cylinder with lid in two pieces, one oak outer case, one press with three divisions for making cylinders, and one thermometer— 10° to +50° C. in tenths. Price complete .. .. .. £19 15 Accessories. 5659* One Small Press .. .. '.. .. .. .. .. £1 10 56601 Extra Screwed Connection if oxygen cylinder is used . . . . . . . . £0 10 5661T Seamless Steel Cylinder filled with 20 ft. oxygen . . . . . . . . £1 17 CROSS STREET • HATTCTN GARDETST, E- C 1022 BAIRD &TATLOCK. (LONDON) LTD. XIX. ANALYSIS Balances Collections Earth Borers Germinating Apparatus, Incubators Shakers Pages. 1024- 1025 1040- 1042 1039 1028-1030 1038 sieves Soil Testing Apparatus 1024, 1037, and 1038 1035-1038 Any new form of Apparatus we shall be pleased to make to order or obtain from the Manufacturers. 14. CROSS STREET HXTTON GARDEN EC BAIRD &. TATLOCK (LONDON) LTD. The following are the different Sections in our Catalogue. Those marked * are also printed separately. Section No. 2.* 3. 4.* 5.* 6.* 7." 8. 9.* 10. 11.* 12. 13. 14. 15. 16. 17.* 18.* 19.* 20.* 21. 22. 23. 24.* Laboratory Fittings Bacteriological Apparatus Chemical Physiology Apparatus Microscopes and Microscopical Accessories Balances and Weights Chemical Apparatus Botanical Apparatus Gas Analysis Apparatus Milk Analysis Apparatus Refractometers Oil Analysis Apparatus Water Analysis Apparatus Cement Testing Apparatus Leather Testing Apparatus Paper Testing Apparatus Physico Chemical Apparatus Pyrometers Calorimeters Seed and Soil Analysis Apparatus Spectroscopes and Polariscopes Volumetric Apparatus Anatomical Models Meteorological Apparatus Assay Apparatus 25.* Chemicals Pages Nos. 14-56 57-161 162^192 193-320 321-382 383-816 817-842 843-886 887-894 895-902 903-926 927-933 934-946 947-949 950-951 952-976 977-1006 1007-1022 1023-1042 1043-1078 1079-1087 1088-1105 1106-1124 1125-1172 1187-1246 14 -CROSS STREET- HATTON GARDEN £• C BAIRD &L TATLOCK. (LONDON) LTD. SECTION No. 19. Apparatus for Seed Testing and Soil Analysis. BAIRD ft T AT LOCK LONDON 5662 5663 5664 5662s Stoneware Pots, 10 by 10 in. inside, with tubulure as used for plant cultivation at Royal Agricultural Society's Experimental Station, Woburn Sands each, 6/- ; per doz. 5663s Diaphanoscope, Dr. Vogel's. Price, without lamp DESCRIPTION. The apparatus consists of a cube-shaped metal case provided with a door. Inside, a mirror is so arranged that, on being slightly moved, rays from a given source of light are thrown in a perpendicular and upward direction on to a perforated copper plate, p, holding about 100 grains of the seeds. The test is conducted as follows : — -Throw a handful of seeds on to the copper plate, and shake gently until the holes are filled, then allow the excess to roll off. By placing the " dull " plate underneath the copper plate a better means of differentiation is obtained. On the passing of the light, it will be found that the floury grains completely prevent the penetration of the rays, whereas the vitreous grains, according to their density, are more or less illumined. Among the latter, those of a dark yellow colour generally predominate, and with a little practice a speedy conclusion may be arrived at regarding the quality of the seeds. Seeds which allow light to pass through their entire length are highly vitreous, and therefore difficult to dissolve. 5664s Diaphanoscope, Lenarcie's, for the investigation of grass seeds, barley, and wheat, for their farinaceousness and hardness. Price, with instructions for use £360 £1 10 0 £2 10 0 1023 BAIRD &TATLOCK (LONDON) LTD. 5665 5669' 5670 5665s Set of Sieves, for beetroot seeds, as used in the laboratory of the German Sugar Industry Association, of stout brass, drilled exact with \, i, i \, 2, 3, and 5 millimetre holes, diameter 125 millimetres •• per set £5 10 0 5666s Set of Sieves for mangel-beetroot seeds, with holes of i, ij, 3^ millimetres, diameter of sieve 10 centimetres .. .. .. .. per set £0 10 6 5667s Universal Clover Sieves for dodder, set consisting of f , i, i£ and ij millimetre holes, diameter of sieves 8 centimetres . . . . . . • • • • • • ..£086 5668s Set of Sieves after D. V. Weinzierl, three sieves 12 centimetres diameter, with holes 1.5, \, J millimetres diameter . . . . . . • • • • . . . . £0 17 6 5669s Farination Apparatus, Grobecker's, with self -filling arrangement to estimate the number of grains, glazed inside, to test 150 grains at a time .. .. .. .. £130 5670s Nobbe's Separator, modified by D. V. Weinzierl, for use by air blast . . . . £0176 5671 5672 5671s Dissecting Set of finest Sheffield manufacture, specially arranged for botanical work, etc., in pol shed mahogany case. Price per set . . List of Contents. One scalpel, 2.\ in. blade. Two needles in handles. Two razors. One magnifier in handle. 5672s Balance, for weighing corn, with set of weights of brass and accessories as per illustration Price fitted in case £1 1 One pair large scissors. One pair small scissors. One pair large forceps. One scalpel, i|-in. blade. £276 CROSS STREET- HATTOTST GARDEIST E-C 1024 BAIRD &12JXOCK (LONDON) LTD. 5673 5674 ! 5673s Balance, after Prof. V. Sulhorst, for weighing corn and ears of corn, as illustrated. This balance can also be used for weighing plants and roots, measuring transpiration, etc. . . 5674s Westfield Granometer for quickly counting exactly 100 seeds of corn 5675s Glass Cylinder, 100 cubic centimetres graduated in cubic centimetres, for observing the amount of moisture absorbed by a given quantity of seeds . . . . . . each kj-1 ut in 5675 £330 £250 £013 5676 5677 5676s Rubber Stamps, for marking filter paper in squares for seed testing. A. 8 by 8 centimetres in £ centimetre squares . . ..£050 B. 8 by 8 „ i , ..£050 S6773 Simple Seed Testing Apparatus, after D. V. Weinzierl, consisting of a wooden case 15 by 12 in., with five hurdles with glass strip for the paper seed beds, with thermometer and zinc tray, for use at room temperature without burner . . ..£176 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1025 633? BAIRD &TATLOCK (LONDON) LTD. 5678s Seed Testing Incubator or Thermostat, after D. V. Weinzierl, with double walls, size 20 by 16 by 16 in., with glass door with ventilating arrangement and exterior wooden door. The inside of the incubator is fitted with eight hurdles of oak, on which rest twenty glass strips for carrying the paper seed beds, and two zinc trays for earth testing beds, and one tin tray for water. Price, with thermometer, burner, and two regulators, for tem- peratures of 22° C. and 50° C. . . 5679s Seed Testing Incubator as above, 16 by 14 by 14 in. back to front, with six hurdles and with two regulators for 20° C. and 50° C. . . £16 16 0 £13 15 0 5680 56803 Separator, Weinzierl's, for the quantitative estimation of chaff in seeds and feeding stuff, works exact and with great rapidity . . . . . . . . . . £12 10 0 14 -CROSS STREET • HATTCHSr GARDETST, E-C 1026 BAIRD &TATLOCK (LOM)ON) LTD. 5681 5682 5683-5685 5681s Soxhlet's Autoclave, for a number of tests under pressure in lieu of pressure bottles ; for determination of starch in grains, and diastastic power of malt. The copper boiler is iyj centimetres inside diameter, 25 centimetres inside depth, brass cover, bridge clamp and screw, safety lever with sliding weight, blow-off valve, pressure gauge, spanner, tested to 15 atmospheres. With tray support and 10 metal beakers with covers and burners (Konig's Untersuchung landwirtschaftlich und gewerblich wichtiger Stoffe, Fig. 25, p. 231, or Wiley's " Principles and Practice of Agricultural Analysis ") . . . . . . £12 5 0 5682s Potometer, simple form, improved, designed by G. H. Pethybridge, Esq., Ph.D., B.Sc. each £076 As described in Scientific Proceedings of Royal Dublin Society, published I3th February, 1904. 56835 Grain Tester, by Brauer ; the space required by a weight unit of any kind of grain serves as a measure in ascertaining the quality. Apparatus, for testing heavy grains, such as wheat, rye, barley, and oil seeds . . . . . . . . . . ..£300 )684S Apparatus, for testing light grains, such as spelt, emmer, etc. . . . . . . £300 >685S Apparatus, for testing very light grains . . . . . . . . . . ..£400 A comparison table mounted on linen is supplied with each apparatus. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1027 BAIRD &TATLOCK (LONDON) LTD. 5686 5686 (top view) 5686s Seed Germinating Apparatus, Schonjahn's, consisting of glass vessel with porcelain sieve, cover, and thermometer . . . . . . . . • • • • each £016 5688 5689 5690 5688s Seed Germinating Apparatus, for all kinds of seeds depending upon a continual equal evaporation of water, without thermometer. 14 by 21 28 by 28 42 by 42 centimetres. 18/6 £1 10 0 £250 5689' Clover Sampler, nickelled with steel point, in case . . 5690' Clover Sampler, Nobbe's, to take average samples of clover and similar seeds, consisting of a metal vessel and tube, tube having a bore of 6 millimetres and notch at end £010 £0 4 5691 569 19 Corn Sampler, brass, Nobbe's . . £0 CROSS STREET • HATTCTrST GARDEN, E 1028 BAIRD &TATLOCK (LONDON) LTD. 5692 5692s Germinating Apparatus, for germinating seedlings for botanical work and for seed testing, size 36 in. long by 18 in. wide, top glazed, made of zinc. Price, complete with burner, draining tube, and Reichert's regulator . . . . . . . . . . £6100 See article by H. Rodewald, Kiel, in pamphlet " Die Landwirtschaflichen Versuchs Station," published by Paul Parey, Berlin, band xlix., heft iv. and v., 1897, pp. 278-282. 5693-5694 5695 Accessories for No. 5692. Porous trays, 2§ by 2§ in., with rim for seeds 2 by 2 in., Porous pots, 3 in. high by z\ in. diameter at top, for seedlings, 5696 per gross £140 £130 per doz., 3/6 ; per gross £1 15 0 blocks, 4! in. diameter by ~i\ in. thick, with depression \ in. deep .. per doz. £0 11 0 1029 BAIRD &.TATLOCK (LONDON) LTD. 5697-5698 Seed Germinating Apparatus, consisting of dish with slotted edge and glass plate with slots to correspond with the slots in dish. The seeds are germinated in sand, and a wooden disc with projections is used for making 100 depressions in the sand. A glass cover fits over all to keep out the dust. This pattern is used by Dr. Deyer of Budapest. each, 4/- ; per doz. 5697s Price of dish with cover 5698s „ moulding disc each - 5699 5700 5701 5702 5701s Seed Testing Apparatus after Stainer, with glass bell jar . . 5702s Clover Testing Machine, after Robes, length 90 centimetres, width 45 centimetres, height 65 centimetres . . £2 £0 5 3 5699s Barley Germinating Box, of teak, with perforated zinc bottom, with thermometer (see W. Frew's article inf.S.C.L, March 1901, pp. 221, 222) . . . . each £0 10 5700s Germinating Apparatus, of nickel-plated brass, by Professor 0. Reinke . . . . £0 12 £0 11 0 £5 15 CROSS STREET • HATTOTST GARDETST, E-C 103C BAIRD &TATLOCK (LONDON) LTD. 5703T Moisture Testing Apparatus, complete with set of glass flasks, graduated measuring cylinders for moisture, thermometer, measuring cylinders for oil, rubber stoppers, test tube brushes, etc., and fitted with burners for gas, or lamps for denatured alcohol : A. Two-compartment Tester . . . . . . . . . . . . . . £12 5 0 B. Four-compartment Tester . . . . . . . . . . . . £18 5 0 C. Six-Compartment Tester .. .. .. .. .. .. .. £23 5 0 MOISTURE TESTER— Brown and Duvel Patent. The apparatus described is the standard used by the United States Department of Agriculture, and the South African Depart- ment of Agriculture, for determining the moisture content of whole grain. It is similarly used in the United States by the State Agricultural Colleges and Experiment Stations ; the Grain and Inspection Departments in Baltimore, Philadelphia, New York, Boston, Mobile, New Orleans, Galveston, Chicago, St. Louis, Kansas City, Omaha, Peoria, Minneapolis, Duluth, Toledo, Detroit, and many of the smaller markets, private grain firms, and operators of grain elevators in the terminal markets, and at country shipping points, brewers, distillers, millers, etc. These testers are now being installed by the Quartermaster-General of the United States Army at nineteen of the principal army posts, so that all oats and maize can be purchased on the basis of its true feeding value, i.e., on a moisture test, . Fig i. — Exterior View of a Six-Compartment Tester. 1031 BAIRD &TATLOCK: (LONDON) LTD. GENERAL DESCRIPTION OF METHOD AND APPARATUS. The method consists in boiling the whole grain in a mineral oil having a flash-point much above the boiling point of water, condensing the water which distils off, and collecting and measuring it in a suitable graduate. A single moisture determination can be made in twenty-five to thirty minutes, and with a standard six-compartment machim an equal number of tests can be made in approximately the same time. 'By the use of three six-compartment machines, one mln a" d a helper can readilv make two hundred tests in a day of eight hours, or an average of approximately two and a haH mfnutes for each test. Making moisture determinations by this method does not reqmre a tramed chemist. The tests can be made satisfactorily by any careful worker who is honest and able to follow simple instructions. • A Two-Compartment Machine is also made. I NM RUBBER STOPPED - Fig 2. — Sectional View, showing the various parts properly connected _for use. A. Distillation Flask in position, f in. above the wire gauze, B. Distillation Flask in wooden rack, used only during filling. Rules for Making Tests. Carefully weigh the desired quantity of the substance to be tested, and empty immediately into the special distillation flask, to which add 150 cubic centimetres of oil and shake slightly so that the two become well mixed. Insert the thermometer, which should be adjusted in the No. 5 rubber stopper, so that when the latter is firmly in place the mercury bulb of the thermometer will be four-fifths immersed in the oil (see Fig. 3). If the mercury bulb of the thermometer is near the bottom of the flask the percentage of moisture will be too low. Place the flask in its proper compartment, and by means of the No. 3 rubber stopper connect the side tube of the flask with the thimble of the glass condenser tube, which extends down through the cold water tank, so that the moisture which is liberated frcm the grain or other substance will be condensed an.d collected in the graduated cylinder beneath the tank. Cover the flask, then ignite the gas, adjusting the flame so that it will require about twenty minutes to reach the desired temperature. When the desired temperature is reached, which varies with different grains, extinguish the flame quickly. As soon as the water stops dropping from the condenser tube, which usually requires from four to six minutes, the test is complete. CROSS STREET • HATTOTST GARDE1ST, E-C 1032 BAIRD &TATLOCK (LONDON) LTD. Fig. 3. — Distillation Flask. Showing the correct adjustment of the thermometer. Oil for the Moisture Test. The oil used for making the test must be free from water, and should have a flash-point of from 200° to 205° C. (open cup) to avoid danger from fire, and a viscosity of 10 or 15 at 20° C. (Engler) so that it will run freely at normal room temperature. Oils of this character are found among many grades of lubricating oils, especially those known as " engine oils," and can be purchased from most local dealers. Cylinder Oils should not be used. They are too heavy and will not give satisfactory results. After the test is completed and while the oil is still hot, empty the contents of the flask into a strainer in order to recover the oil, which can be used repeatedly. How to Test Different Substances. Detailed instructions have been worked out for making moisture determinations of a limited number of substances, as follows : Barley. — Use 100 grammes of grain, 150 cubic centimetres of oil, and extinguish the flame when the thermometer registers 190° C. Corn (Maize). — Use 100 grammes of grain, 150 cubic centimetres of oil, and extinguish the flame when the thermometer registers 190° C. This method, however, cannot be used with the pop corns. Corn cob. Use 50 grammes of cob cut in pieces that can be easily removed from the flask, 150 cubic centimetres of oil, and extinguish the flame when the thermometer registers 190° C. Cotton seed. — Use 50 grammes of seed, 150 cubic centimetres of oil, and extinguish the flame when the thermometer regis- ters 190° C. Flax seed. — Use 100 grammes of seed, 150 cubic centimetres of oil, and extinguish the flame when the thermometer regis- ters 175° C. Kaffir. — Use 100 grammes of grain, 150 cubic centimetres of oil, and extinguish the flame when the thermometer registers 190° C. Oats. — Use 50 grammes of grain, 150 cubic centimetres of oil, and extinguish the flame when the thermometer registers 195° C. In oats that are light and chaffy, special care should be taken to insure the thorough mixing of the oil and grain, and to heat with a slower flame in order to reduce the foaming to a minimum. In extreme cases it may be necessary to add an extra 50 cen- timetres of oil. Rice (unhulled). — Use 100 grammes of grain, 150 cubic centimetres of oil, and extinguish the flame when the thermometer registers 190° C. Rye. — Use 100 grammes of grain, 150 cubic centimetres of oil, and extinguish the flame when the thermometer registers 175° C. Soya Beans. — Use 100 grammes of beans and 150 cubic centimetres of oil, and extinguish the flame when the thermometer registers 170° C. Wheat. — Use 100 grammes of grain, 150 cubic centimetres of oil, and extinguish the flame when the thermometer registers 1 80° C. 1033 BAIRD &TATLOCK (LONDON) LTD. Reading the Percentage of Moisture. The small graduated cylinders for measuring the moisture should have a capacity of at least twenty-five ^centimetres. They should bewrefully graduated in fifths, so that the readings can readily be made m tenths ^f mo^ture^ridnaHv con for the test, the number of cubic centimetres of water in the graduate corresponds ^^^^^S^. 3metres of tained in the sample. If only 50 grammes are used, as is necessary with some substances, the number water in the graduate is equivalent to one-half of the moisture percentage. Fig. 4. Graduated Measuring Cylinder, showing 20 per cent, of moisture. Graduated Measuring Cylinders. The standard cylinders for measuring the moisture have a capacity of twenty-five cubic centimetres (see Fig. 4), and; carefully graduated in fifths so that the reading can readily be made to tenths, all readings being made directly in per cent., unless other than 100 grammes are used for the test. In making the moisture determinations a small quantity of the oil is carried over into the measuring cylinder and collects on the surface of the water, so that the reading should be made at the bottom of the meniscus between the oil and water, as shown in Fig. 4. Should the oil and water not separate readily, whirl the graduated cylinder by rolling quickly between the two hands. After each test the graduated cylinders should be cleaned, for which purpose we recommend swabs with sponge tips and rattan handles, as shown in Fig. 5. HBBtfiS Fig. 5. — Swab or Test Tube Cleaner. Thermometers. — Graduated in degrees to 200° C., 13 in. long by 9.32 in. diameter. Balance. — While not a part of the apparatus a balance is necessary for weighing the samples. Nineteen Important Points. In making tests special attention should be given to the following points : — 1. The moisture tester should be installed in a place where it will not be exposed to strong air currents. 2. The testers can be equipped for burning alcohol or gasoline, but gas is to be preferred whenever available. 3. The wire gauze, with asbestos centre, should be kept in good condition, so that the flame does not play directly on the bottom of the flask. 4. The bottom of the flask should be not less than § of an inch above the wire gauze. 5. See that the column of mercury in the thermometer is continuous ; if broken, it should be shaken down. 6. Adjust the thermometers in the rubber stoppers so that the bulbs of the thermometers will be approximately four- fifths immersed in the oil. CROSS STREET • HATTOTST GARDETST, E-C 1034 7. Keep a good supply of cold water running through the condenser tank. 8. Adjust the flame so that about 20 minutes are required to reach the prescribed temperature. 9. If the moisture content of the sample is high so that there is a tendency to boil over, lower the flame until a consider- able portion of the water is distilled over. 10. When the thermometers register the prescribed temperature extinguish the flame promptly. n. After the flame is extinguished, a slight gradual increase in temperature is to be expected. A sudden increase or a sudden decrease of several degrees in temperature indicates that the flame was too intense during the latter part of the heating, and the test should be repeated. 12. See that there is no water in the graduated cylinder before starting the test. 13. Read the percentage of moisture in the graduated cylinder beneath the layer of oil on top of the water. 14. If the water which distils over is discoloured, the substance has evidently been burned, and the test should b3 repsated. 15. When not in use keep the flasks in position in the compartments, and all connections made as for making a test. 16. Before making a test in a new flask, run a preliminary sample so that all of the flasks will be in uniform condition. 17. Draw all samples carefully and keep them in air-tight containers until ready to make the test. They lose moisture rapidly when exposed to the air. 18. Place the scales on a firm support and see that they are in balance before making a weighing. 19. The specific instructions for making tests, as given, do not apply to modified forms of testers. Size Two-Compartment Six-Compartment Approximate Shipping M'ment. Cubic ft. 20 40 Approximate Nett Weight. Ibs. 55 215 Approximate Gross Weight. Ibs. 185 370 5704 5705 A5705 5704 Experimental Malt Kiln, of iron, as devised by W. Frew, Esq. (see/.S.C. /., soth March, 1901, p. 223). Price without burners 5705 Schultze's Elutriating Apparatus, with metal cap and glass funnel . . A5705 Soil Washing Apparatus, on stand, with water reservoir £3 10 £0 5 £1 10 1035 BAIRD &TATLOCK (LOM>ON) LTD. 5706 5707 5706 Heinrich's Apparatus, for the determination of permeability in the open field, bottles of 10 litres capacity, with strong iron box and indiarubber tubing, etc. . . . . £150 5707s Apparatus, for estimating the capillary attraction of soils, tubes graduated in millimetre3, with enamelled back, on teak stand with zinc trough, complete for ten estimations . . £3 10 (Fig. 19, Wiley's " Chemistry.") 570S 5709 5710 5711 5712 5708 Benningsen's Soil Testing Apparatus, flask with graduated neck, 10 cubic centimetres in TVths. Capacity of bulb about 150 cubic centimetres 5709 Knop's Soil Testing Apparatus, jar with three taps, 3, 4, and 5 millimetres bore 5710 Soil Testing Apparatus, Broegger-Harada's separators, bore of upper stopcock 15 milli- metres 5711 Soil Testing Apparatus (Thoulet's separator) 5712* Hilgard's Churn Elutriator, for soil analysis (Fig. 35, Wiley's " Chemistry," vol. i.) £030 £150 £150 £0 16 0 £5 10 0 CROSS STREET • HATTCTNT GARDEKT, E'C BAIRD &TXTLOCK (LONDON) LTD. 5713 5713s Flugge's Cylinder, for determining the volume of pores in soil £0 17 6 5714 5715 5716 5714s Standard Sieve, with brass frame, 20 centimetres diameter, for testing basic slag, with ' top and bottom, 100 by 100 mesh with cover and receiver 5715 Sieves, brass wire, japanned tin frame. Diameter . . . , . . Mesh 30 ... „ 60 „ 90 .. 5716 Sieves, brass wire, japanned tin frame, with cover and bottom. In sets of four, 30, 60, 90, and 100 mesh. Diameter . . . . . . . . 3 4 6 . 9 in. Price per set .. .. .. 4/3 5/3 7/- 11/6 £150 3 4 6 9 in. I/- 1/2 1/6 21- 1/2 1/4 1/9 3/- 1/4 1/8 21- 3/6 5717 >717 Sieves, wooden frame, 5J by 3$ by ij in. deep. Mesh . . 10 20 30 40 Price .. 1/6 1/6 1/9 2/- 2/3 60 80 100 2/4 2/6 3/- I2O 3/6 each. jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1037 BAIRD &TATLOCK (LONDON) LTD. 5718 5720-5727 i 5 2.O 2.5 3-o 3-5 4 5 mm 6/- 61- 61- 61- 61- 61- 6/- each 91- 91- 91- 91- 91- 91- Q /- / ~ *f 12/- 121- 121- 121- 121- 121- 121- „ . . 4 6 8 in. .. 4/6 5/6 6/6 each. bove sieves. i. g 2.0 2-5 3-0 3-5 4 5 mm. 4/- 4(- 3/9 3/6 5718 Sieves for soil analysis, etc., bottom of perforated brass sheet, rims of spun brass, polished. Holes 0.5 i Diam. 4 in. 6/6 61- „ 6 in. 10/- 91- „ 8 in. 15/- 121- Cover and receiver for above Price 5719 Perforated Brass Sheet as used for above sieves. Holes 0.5 i Per sq. ft. 7/6 4/- Largest size sheet supplied, 4 ft. by 2 ft. WAGNER'S SHAKING APPARATUS for the estimation of phosphoric and phosphates soluble in citrate solutions. The holder for neck of bottle is adjustable to suit bottles of varying heights. The apparatus is arranged for rotating by hand or motor. (Described in Wiley's " Principles and Practice of Agricultural Analysis," vol. ii.) 5720 Wagner's Shaking Apparatus with six bottles, plain, 500 cubic cm. capacity £3 3 5721 Wagner's Shaking Apparatus „ ten ,, ,, 500 „ „ £3 10 5722 Wagner's Shaking Apparatus „ six ,, „ 1,000 „ „ £4 0 5723 Wagner's Shaking Apparatus „ ten „ „ 1,000 „ „ £4 17 5724 Extra bottles, plain, 500 cubic centimetres capacity . . . . each, 1/2 ; per doz. 5725 „ „ 1,000 „ „ „ 1/9; 5726 Extra bottles, graduated, with mark on neck, 500 cubic centimetres capacity each, 1/6 ; per doz. 5727 Extra bottles, graduated, with mark on neck, 1,000 cubic centimetres capacity each, 2/3 ; per doz. Hot-air motor and guide pulley (as illustrated), extra. (See Nos. 908-909 for Motors for driving above.) acid in slags Price without Motor. £0 £1 13 0 £0 17 £16 0 0 0 0 CROSS STREET- HATTCTNr GARDEN E-C 1038 BAIRD &TATLOCK (LONDON) LTD. 5728 5729 5730 5731 5728 Earth Borer, Frankel's pattern, for taking samples of earth from a depth. i 2 metres long. 32/- 38/- each. 5729 Earth Borer, Gruner's pattern, with wood handle. 123 metres long. 25/- 30/- 35/- each. 5730 Earth Borer, Orth's pattern, in hollow brass shield, rod marked every 10 centimetres. 80 100 centimetres. 21 1- 23 /- each. 5731 Earth Borer, American pattern, i metre long, with handle. Diameter of blades . . . . 50 80 105 150 millimetres. Price .. .. 17J- 19/' 21/' 25/- each. Longer metal rod supplied if required, extra price 4/- per metre. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. AipctuU /i. t- t- - 5732 5732r Collection of Weed Seeds as found in commercial samples of grass and clover seeds, mounted and arranged by Professor T. Percival, M.A., University College, Reading. Each set contains 200 species in two cases complete . . . . . . ..£50 (See pages 1041-1042.) Seeds of Weeds found in commercial samples of Grass and Clover Seeds. 1. The determination of the amount of the impurities in samples of grass and clover seeds is of considerable importance seedsmen and fanners since the worthless impurities have to be paid for at the same rate as the good seed. 2. In addition to the financial question involved in thus buying useless material there is another and more serious questio connected with seed impurities, namely, the distribution of weeds. It is practically impossible to harvest the seeds of any crop without obtaining weed seeds with them, and even it samples, which are usually collected by hand from wild plants, the seeds of weeds are always found. Troublesome pests of cultivated land have been, and are being, spread continually in all parts of the world through the use of impure samples. Some of them, such as dodder, thistles, and charlock are more dangerous than others on account of the great difficulty of completely eradicating them when once established, but all are objectionable. The present collection has been made and issued with a view of providing seedsmen, farmers, and students in colleges and schools of agriculture with specimens of the chief weed seeds found in commercial samples of grass and clover seeds, both of British and foreign origin. 3. The various species of weeds present in commercial samples of farm seeds very frequently give a clue to the country of origin of the samples. The collection is intended to be of service also from this point of view. A number of common European weeds, such as Ranunculus acris, Neslea paniculata, Thlaspi arvense, Camelina saliva, Matricaria inodora, Rumex crispus, Sonchus oleraceus, and many others have been transported and established among the clover and grass crops of the colonies and many parts of the American continent ; a few native American weeds also have found a home in Southern Europe. On account of these facts the presence of such species in samples cannot be used as evidence of the source of origin of the latter. . Certain species, however, may be considered as characteristic of certain countries only, being rarely or never found except in samples of seeds grown in those countries. For example : (a) In North American samples these seeds are characteristic — Nos. 25, 82, 83, 122, 130, 131, 145, 146, 169, 170, 192, 195- (fc) Nos. 124, 126, are indicative of South America. (c) Characteristic of Russian and Eastern European samples are Nos. 6, 7, 15, 21, 31, 45, 56, 75, 86, 101, 156. (d) Mid-European samples usually contain Nos. 7, 10, 14, 19, 23, 30, 33, 52, 64, 65, 70, 87, 97, 99, 152, 153, 154, 167- (e) Nos. I, 59, 76, in, 155, are found chiefly in samples from Southern Europe. CROSS STREET • HATTOTST GARDE1ST, E-C 1040 BAIRD &TATLOCK. (LONDON) LTD. Ranunculaceae. 1. Thalictrum acquilegifoliura L. 2. Ranunculus sceleratus L. 3. Ranunculus acris L, 4. Ranunculus repens L. 5. Ranunculus arvensis L. 6. Nigella arvensis L. 7. Delphinium consolida L. Papaveraceae. 8. Papaver dubium L. 9. Papaver Rhoeas L. 10. Glaucium corniculatum Curt. Fumariaceae. 11. Fumaria officinalis L. Cruciferae. 12. Barbarea vulgaris R. Br. 13. Sisymbrium officinale scop. 14. Erysimum cheiranthoides L. 15. Erysimum orientale R. B. 16. Brassica nigra Koch. 17. Sinapis arvenis L. 18. Eruca sativa Lmk. 19. Berteroa incana D. C. 20. Camelina sativa Crnlz. 21. Camelina dentata Pers. 22. Capsella Bursa-pastoris Mnch. 23. Lepidium campestre R.Br. 24. Lepidium apetalum Willd. 25. Lepidium virginicum L. 26. Thlaspi arvense L. 27. Neslea paniculata Desv. Resedacese. 28. Reseda lutea L Violaceae. 29. Viola tricolor L. Caryophyllaceae. 30. Saponaria officinalis L. 31. Saponaria Vaccaria L. 32. Sileneinflata Sm. 33. Silene dichotoma Ehrh. 34. Silene noctiflora L. 35. Lychnis Flos-cuculi L. 36. Lychnis vespertina L. 37. Agrostemma Githago L. 38 Cerastium triviale Link. 39. Stellaria media Vill. 40. Stellaria graminea L. 41. Spergula arvensis L. Portulacaceae. 42. Portulaca oleracea /.. Hypericaceae. 43. Hypericum perforatum L. Malvaceae. 44. Malva sylvestris L. 45. Hibiscus Trionum L. Geraniaceae. 46. Geranium pratense L. 47. Geranium pusillum L. 48. Geranium dissectum L Leguminosae. 49. Ononis repens L. 50. Melilotus officinalis Desr. 51. Melilotus alba Desr. 52. Melilotus r.oeruleus Desr. 53. Trifolium arvense L. 54. Trifolium procumbens L. 55. Trifolium minus Sm. 56. Trifolium suaveolens, Willd. 57. Lotus corniculatus L. 58. Lotus uliginosus Schk. 59. Arthrolobium scorpioides Ztec;. 60. Vicia hirsuta Koch. 61. Vicia tetrasperma Mnch. 62. Lathyris pratensis L. Rosaceae. 63. Potentilla monspeliensis L. Umbelliferae. 64. Conium maculatum L. 65. Bupleurum rotundifolium L. - 66. Carum Carui L. 67. Petroselinum sativum Hotfm. 68. Pimpinella Anisum /-. 69. Aethusa Cynapium L. 70. Meum athamanticum Jacq. 71. , DaucusCarota L. 72. Torilis Anthriscus Gmel. < Rubiaeeae. 73. Galium Mollugo L. 74. Galium Aparine L. 75. Asperula azurea Jb. and Spch. 76. Asperula cynanchica L. 77. Sherardia arvensis L. Valerianacere. 78. Valeriana dioica L. 79. Valeriana officinalis L. Dipsaceae. 80. Knautia arvensis Coult. Compositre. 81. Iva xanthifolia Null. 82. Ambrosia artemisiaefolia L. 83. Rudbeckia hirta L. 84. Achillea Ptarmica L. 85. Achillea Millefolium L. 86. Anthemis tinctoria L. 87. Anthemis austriaca Jacq. 88. Anthemis arvensis /.. 89. Anthemis Cotula L. go. Matricaria Chamomilla L. 91. Matricaria inodora L. 92. Chrysanthemum segetum L. 93. Chrysanthemum Leucanthemum L. 94. Tanacetum vulgare L. 95. Senecio vulgaris L. 96. Senacio Jacobea L. 97. Centaurea Jacea L. 98. Centaurea Cyanus L 99. Centaurea maculosa Lmk. 100. Centaurea nigra L. 101. Carduus acanthoides L. 102. Cnicus lanceolatus Haftm. 103. Cnicus arvensis Hoftm. 104. Cichorium Intybus L. 105. Lapsana communis L. 106. Crepis vireus L, 107. Hieracium Pilosella L. 108. Hieracium aurantiacum /.. 109. Hypochaeris radicata L. no. Leontodon autumnalis L. 111. Helminthia echioides Gart. 112. Taraxacum officinale Web. 113. Lactuca virosa L. 114. Lactuca Scariola £.. 115. Sonchus arvensis L. 116. Sonchus oleraceus L. 117. Sonchus asper Hoffm. Primulaceae. 118. Anagallis arvensis L. Boraglnaceae. 119. Lappula myosotis Mnch. 120. Echium vulgare L. 121. Lithospermum arvense L. 122. Phacelia tanacetifolia Benth. Convolvulaceae. 123. Cuscuta Trifolii Bab. 124. Cuscuta racemosa Mart. 125. Cuscuta epilinum Westn. Solanaceae. 126. Nicandra physaloides Garln. 127. Hyoscyamus niger L. Plantagunacece. 128. Plantago major L. 129. Plantago lanceolata L. 130. Plantago Rugelii Dec. 131. Plantago aristata Mich. 132. Plantago Psyllium L. Scrophulariaceae. 133. Verbascum Thapsus L. 134. Linaria spuria Mill. 135. Linaria vulgaris Mill. 136. Linaria minor L. 137. Scrophularia nodosa L. 138. Veronica agrestis L. 139. Veronica arvensis L. 140. Veronica officinalis L. 141. Veronica Chamaedrys L. 142. Bartsia Odontites Huds. 143. Euphrasia officinalis /.. Verbenaceae. 144. Verbena officinalis L. 145. Verbena urticaefolia L. 146. Verbena stricta Vent. 147. Verbena hastata L. Labiatae. 148. Mentha aquatica L. 149. Lycopus europae'js L. 150. Origanum vulgare L. 151. Calamintha Clinopodium Benth. 152. Salvia officinalis i. 153. Salvia pratensis L. 154. Salvia sylvestris L. 155. Salvia verticillata L. 156. Salvia turkestanica Regel. 157. Nepeta Cataria L. 158. Dracocephalumparviflorum.Vii/i 159. Prunella vulgaris L. 160. Scutellaria galericulata L. 161. Stachys palustris L. > 162. Stachys betonica Benth. 163. Galeopsis Tetrahit L. \ CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1041 BAIR-D &.TATLOCK (LONDON) LTD. Labiatae — contd. 164. Teucrium Botrys L. 165. Ajuga reptans i. 166. Leonurus Cardiaca L. 167. Chaiturus Marrubiastrum Rclib. Amaranthacese. 168. Amaranthus retroflexus L. 169. Amaranthus albus L. 170. Amaranthus blitoides Wats. Chenapodiaceae. 171. Chenopodium album L. 172. Atriplex hastata L. 173. Salsola Tragus L. 174. Axyris amarantoides L. Polygonaceae. 175. Polygonum Persicaria L. 176. Polygonum aviculare L. 177. Polygonum Convolvulus L. 178. Rumex crispus L. 179. Rumex Acetosa L. 180. Rumex Acetosella L. EuphorbiaceaD. 181. Euphoriba Helioscopia L. 182. Euphoriba Pelplus L. 183. Euphorbia Cyparissias L. Urticacere. 184. Urtica dioica L. Juncaceae. 185. Juncus bufonius L. Alismaceae. 1 86. Alisma Plantago L. Cyperaceae. 187. Scirpus sylvaticus L. 188. Carex muricata L. Gramineae. 189. Panicum sanguinale L. 190. Panicum lineare Kr. 191. Panicum Crus-Galli L. 192. Panicum capillare L. 193. Paspalum stoloniferum Base. 194. Paspalum dilatatum Michx 195. Paspalum laeve Michx. 196. Setaria viridis Beauv. 197. Setaria glauca Beauv. 198. Alopecurus agrestis L. 199. Milium effusum L. 200. Deschampsia flexuosa Tiin A5732T Collection of Cereals, specified below. Issued by Prof. John Percival, M.A., F.L.S., University College, Reading. Price in case complete £200 WHEATS. Small Spelt Wheat. (Triticum monococcum L.) Engrain commun. „ double. Emmer. (Trilicum dicoccum Schr.) White Emmer. Red Black Common Spelt Wheat. (Trilicum Spelta L.) Ordinary beardless. Red Ordinary bearded. Black " „ Polish Wheat. (Triticum Polonicum L.) Macaroni Wheat : " Hard " Wheat. ( Trilicum durum Desf.) Kubanka. Madona. Medeah. Rivet or Cone Wheat. ( Triticum turgidum L.) Poulard Taganrog. Blue Cone. Rivet. Mummy ; Miracle of Egyptian Wheat. (Trilicum compositum L.) Dwarf or Club Wheat. (Triticum compactum Host.) Sicilian Red. Beardless Herisson : Binkel. (T. imberbe Desr.) Beardless Rough Chaff. Bearded Herisson : Igel. (T. hystrix Ser.) Common Wheat. ( Triticum vulgare Vill.) White Chaff, Beardless. Talavera. Fife. Windsor Forest. Squarehead. Rough Chaff. Red Chaff, Beardless. Red Lammas. Golden Drop. Standard Red. Squareheads' Master. While Chaff. Bearded. Bearded Summer. Shirreff's Bearded. Red Chaff Bearded. Bearded Winter Red. Fox. Black Chaff Bearded, Persian Black. BARLEYS. Six-rowed Barley. (Hordeum hexaslichon L.) Bere or Bigg. (Hordeum vulgare L.) Winter Bere. Black Naked Guymalaye. Nepal " Wheat." (H. tri/urcatum Jacq.) Two-rowed Barleys. Peacock, Battledore, Fan or Sprat Barley. (Hordeum Zeocriton L.) Ordinary Two-rowed Barleys. (Hordeum distichon L.) a. Erect-eared. Goldthorpe. b. Bent-eared. Old common. Large naked. Black. Chevalier. RYE. Common Rye. (Secale cereale L.) St. John's Day or Midsummer Rye. Spring Rye. Winter Giant. Schlanstedt. Wasa. Common Oat. (Avena saliva L.) Potato. White Canadian. Abundance. Black Winter. Large naked Oat. (Avena chinensis Metz.) Small naked Oat. (Avena nuda L.) OATS. Tartarean Oat. (Avena orientalis Schreb.) White Tartar. Yellow Black CROSS STREET • HATTCTSr GARDEN, E-C XX Spectroscopes, Browning Hilger Reichert • Schmidt and Haensch Student Thorpe Polariscopes, Laurent Schmidt and Haensch Polarising Set, Educational 1043, 1044. 1048, and 1049 1045, 1049, 1050, and 1053 1044 1043, 1045, 1050, 1052 1046- 1048 1047 1073- 1078 1054-1073 1078 14. CROSS STREET. HXTTON GARDEN. EC BA1RD & TXTLOCK (LOM)ON) LTD. The following are the different Sections in oui Catalogue. Those marked * are also printec separately. Pages NOE. Section No. 1.* Laboratory Fittings 14*5 ti 2.* Bacteriological Apparatus . 57-16 i* 3. Chemical Physiology Apparatus 162.lt i » 4.* Microscopes and Microscopical Accessories 193-321 i » 5.* Balances and Weights 321-38: *» 6.* Chemical Apparatus 383*81i t» 7.* Botanical Apparatus 817-84! » » 8. Gas Analysis Apparatus 843-88i 99 9." Milk Analysis Apparatus 887-89' it 10. Refractometers 895-90! » » 11." Oil Analysis Apparatus 903 -92< t* 12. Wa^er Analysis Apparatus 927-93! ** 13. Cement Testing Apparatus 934 -94> t » 14. Leather Testing Apparatus 947-94' * » 15. Paper Testing Apparatus 950-95 »» 16. Physico Chemical Apparatus 952-97 i » 17.* Pyrometers 977-100 n 18." Calorimeters 1007-102 * 9 19.* Seed and Soil Analysis Apparatus 1023-104 9 9 20.* Spectroscopes and Polariscopes 1043-107; ,9 21. Volumetric Apparatus 1079-108 t* 22. Anatomical Models 1088-110 t * 23. Meteorological Apparatus 1106-112 91 24.* Assay Apparatus 1125-117 99 25.* Chemicals 1187-124 /?>*»-. JG 14 CROSS STREET HATTO>J GARDEN, CTBH F • C • r 111 BAIRD &.TATLOCK (LONDON) LTD. SECTION No. 20. Spectroscopes and Polariscopes. 5733-5734 5733T Browning's Pocket Spectroscope, with plain slit, in case . . 57341 Browning's Pocket Spectroscope, with adjustable slit, in case The above instruments will show many of Fraunhofer's lines, the bright lines of the metals and gases, and the absorption bands in coloured gases, crystals, or liquids. £156 £1 13 0 5735-5736 5735T Spectroscope, pocket, Schmidt & Haensch, with three prisms and plain slit, in case . . £140 5736T Spectroscope, pocket, Schmidt & Haensch, with three prisms and adjustable slit, in case £1 10 0 5737 737T Spectroscope, Schmidt & Haensch's, as above, with right-angled prism and reflecting mirror for showing two spectra in comparison, in case . . . . . . . . £250 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1043 BAIRD &TXTLOCK (LONDON) LTD. 5738 5738T Browning's New Miniature Spectroscope, with micrometer, adjustable slit, achromatic lens, and right-angled prism for showing two spectra in comparison. Complete, in case £3 10 0 This portable and complete instrument may be used for showing any of the leading experiments in spectrum analysis, the Fraunhofer lines, the lines in the spectra of the metals, and the alkaline earths and alkalies, the spectra of gases, and absorption bands. Applied to a telescope, it may be used for viewing th I lines of the solar prominences. It can also be used as a micro-spectroscope. The position of the bands in any spectrum may be measured with the attached micrometer. 5739 5739T Direct-Vision Spectroscope, Browning's, with five prisms, fitted in mahogany case . . £5150 This spectroscope is a most powerful and portable direct-vision instrument, easily separating the D lines in the solar spectrum. A57391 Direct Vision Spectro'scope, as above, on brass tripod stand with clips . . . . £7 17 0 5741 5740* Pocket Spectroscope, for clinical purposes, showing the Fraunhofer lines distinctly when held to the sky, with adjustable slit, comparison prism, and side mirror, in case. . £1 18 0 5741* Pocket Spectroscope as above, with wave-length scale, which is projected upon the spectrum, as a means of measuring the latter . . . . £3 10 0 5742' Coyer Glass Gauge, for quickly and easily measuring the exact thickness of cover Its range of measurement extends from o-oi mm. to o'8 mm. . . £1 10 0 CROSS STREET • HATTON GARDETST, E-C 1044 BAIRD &TATLOCK (LONDON) LTD. 5743 5743T Spectroscope, Schmidt & Haensch, with lenses, disc, and scale, in case 57441 Spectroscope, as above, fitted with waves length scale £4 10 0 £500 5745 5746 745T Spectroscope, Hilger's Direct Vision, Pocket, in brass case 3^ in. long, with adjustable slit £200 746T Student's Spectroscope, on wood stand . . . . . . . . ..£150 iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1045 BAIRD &TmOCK. (LONDON) LTD. 5^47-5748 5747T Student's Spectrometer, No. 2 pattern, as specified below, in case . . . . . . £600 This instrument was designed to meet the requirements of the Department of Agricultural and Technical Instruction for Ireland, for a cheap, yet reliable Spectrometer. It has a protected 5-inch circle, read by vernier to i minute. The circle and telescope are attached to the outer centre and move together. The telescope is counterpoised and provided with cross-wires, rack-motion focussing arrangement, clamp and fine adjustment. The collimator has a protected adjustable slit and clamping ring, so that it caa be set for verticality and focal distance once for all. The prism table is adjustable by means of three levelling screws, and can be raised or lowered to any convenient height ; it can be clamped to the inner centre which carries the vernier, and which is provided with clamp and fine adjustment. The object glasses of both telescope and collimator are about 7 inches in focal length, and have a clear aperture of $ inch. Adjustments are provided for setting the optical axes of telescope and colhmator at right angles to the vertical axis of the Instru- ment. One eyepiece, grating holder, prism clamp and reader are supplied with the Instrument. 5748r Student's Spectrometer, as above, without rack motion and fine adjustments . . £500 ACCESSORIES FOR SPECTROMETERS, Nos. 5747-5748. 57491 with two verniers . . . . . . . . . . . . . . extra £076 5750T Rack motion to collimator . . . . . . . . . . . . ' . . £0100 575 1T With g-inch telescope and collimator . . . . . . . . . . extra £0 5 57521 Comparison prism attached to slit .. . . . . . . . . . . . . £07 5753T Extra dense flint glass prism . . . . . . . . . . . . £0 10 5754T Ordinary dense flint glass prism . . . . . . . . . . £09 5755T Crown glass prism . . . . . . . . . . £090 5756T Hollow prism, with f-inch hole . . . . . . . . £0106 5757T Copy of Roland's grating . . . . . . . . £0 15 0 5758T Illuminating attachment to eyepiece .... £076 5759T Plane parallel mirror, silvered both sides . . . . . . £0100 5760T Large ordinary dense flint glass prism, suitable for the g-inch telescopes . . . . £0160 57611 Ditto, crown glass ...... £0 16 0 57621 „ extra dense flint glass .... £0170 1046 BAIRD &TATLOCK (LONDON) LTD. . f*n~. Beck-Thorp Diffraction Spectroscopes. This series of high-class spectroscopes may be said to be the first serious attempt to apply the advantages of Diffraction Grating to the whole field of spectroscopic research. The list includes small instruments to be carried in the pocket by those who are connected with colour printing, or any chemical or colour industry, while the price of the simplest form is so small that every physiology student, every chemical student, every engineer should have one. From this form the list proceeds to the more perfect instrument with accurate scales of measurement, following on with a Chemical Spectroscope of great dispersion, a Sun Prominence Spectroscope, and finally a Wave Length Spectroscope of such accuracy that the wave length of light may be determined with accuracy. 5763 5763T Beck-Thorp " Minimum " Pocket Diffraction Spectroscope ... This instrument gives a dispersion of about 20°, or about double that of the ordinary direct vision prismatic instrument. It will readily show the more prominent Frauenhofer lines and will distinctly show the rainband lines. It has been supplied largely to the Universities in England for the use of students, and is suitable as a pocket instrument for all classes of colour work and chemical industries. £0 10 0 5764 5764T Beck -Thorp " Regular " Pocket Diffraction Spectroscope This instrument has a dispersion of about 30°, and shows hundreds of lines in the Solar Spectrum, the D line being well separated. The B group is admirably shown. It has a finely made adjustable platinoid slit and a sliding focussing adjustment. It is suitable for the same class of work as No. 5763. £276 5765 5765T Beck-Thorp Patent Reading Pocket Diffraction Spectroscope This instrument has the same optical qualities as No. 5764 last described, but has a most important addition. Upon looking through the instrument the spectrum will be seen, and above the top will be seen an illuminated arrow point. A graduated revolving milled head moves this point along the spectrum, and the position of any line can thus be registered. The gradations of the revolving drum are observed through the lens by a slight shift of the eye, and in this way the positions of numbers of lines can be rapidly recorded during even a short observation. One of the minor advantages of this system of reading is that the pointer is illuminated by the actual source of light that gives rise to the spectrum, and therefore, if the spectrum is brilliant, the pointer will be brilliant ; if the spectrum is dim, the pointer will be dim, and the brightness of one will not overpower the other, but the great advantage of this method of reading is that the readings correspond to the wave-lengths of light. The whole spectrum is divided into 500 divisions, and a glance at the sun, reading two or three important and easily recognised lines, at once gives the ratio that the scale bears to the actual wave length. This instrument has been supplied to physical laboratories. It is being used by the medical profession for blood research, and is specially suitable for the processes of steel manufacture, which depend for their success oa spectrum analysis. £440 BAIRD & TXTLOCK. (LONDON) LTD. 5766-5767 5766T Spectroscope, after Kirchhoff and Bunsen, »vith micrometer scale, and illuminating lamp, adjustable slit arranged for two spectra. Price, without accessories . . Accessories — 5767r Two gas lamps, adjustable, with chimneys 5768T Twelve glass tubes, with two stands 57691 Two tables with illustrations and five lithographed millimetre scales . . £550 £0 10 £0 4 £0 2 5770 5770T Browning's Student's Spectroscope, in stained cabinet This instrument has a prism of extremely dense glass, of superior workmanship. The circle is divided and reads with a vernier, thus dispensing with the inconvenience of an illuminated scale. This arrangement possesses the very great advantage of giving angular measures in place of a perfectly arbitrary scale. The slit is also furnished with a reflecting prism, by means of which two spectra can be shown in the field of view at the same time with ij in. prism divided arc to 360° vernier, etc. £8 0 I 5771 57711 Browning's " Universal " Spectroscope, in cabinet This instrument is of new design and can be used as a spectroscope or spectrometer. It has a I J-in. dense flint prism, achromatic object glasses of about 9 in. focal length, and high-power eyepiece giving a high dispersion. It reads by means of the vernier to i minute, and has clamping screws for fixing in any position. The prism table rotates and may be raised or lowered and levelled by means of levelling screws. The collimator has an adjustable slit, to which is attached a right-angled reflecting prism, so that two spectra may be seen in the field of view and easily compared. £700 1P4.R BAIRD &TATLOCK (LONDON) LTD. 5772 5772T Browning's New Model Spectroscope, " College." Price, complete with ij-in. dense flint prism, comparison prism, magnifier for reading verniers, in cabinet . . . . £8150 This instrument is similar to the new model " Universal " (Fig. 5771), but is fitted with rack-work focussing to telescope, fine screw adjustment to telescope and to verniers. It is also fitted with twa verniers for greater ease and accuracy in reading. 5773* Browning's New Model Spectroscope, " Analyst's," in cabinet . . . . £950 This instrument is exactly similar to the new model "College," No. 5772, but is also provided with rack-work motion to collimator, as well as telescope. 5774 57741 Table Spectroscope, by Hilger, No. 1, "South Kensington Type." The divided circle is 6 in. in diameter, divided all round to read by vernier to one minute of arc. The prism 1 table rotates, has a clamp for the prism, and a division for setting the same. The prism can be of either light i or dense flint as desired. The collimator has a well-made adjustable slit, with non-corrosive jaws, wedge for reducing the aperture, comparison prism, and protective cap. Screw adjustment is also provided for correcting the parallelism of the jaws should this at any time require correction. The telescope has rack and pinion focussing, high and low power eyepieces with spider-webs for measurement, and tangent screw for slow motion. i The objectives of both telescope and collimator are good achromatics of n J in. focal length and ij in. clear i aperture. The above is mounted on a strong iron tripod stand. Price .. .. .. .. .. .. .. .. .. .. £10 10 0 ACCESSORIES FOR ABOVE. 1 5775T Levelling screws to above . . . . . . . . . . . . . . - £1 0 0 5776T Photographic scale adapted on a third tube uniform in design with telescope and collimator £2 15 0 5777T Camera attachment to above . . . . . . . . . . . . ..£776 5778T Screw adjustment to photographic scale . . . . . . . . . . . . £0 12 6 57791 Well-made case, with lock and key . . . . . . . . . . . . £1 15 0 1049 BAIRD &TATLOCK CONDON) LTD. 5787 57871 Ultra-violet Glass Spectrograph, Hilger's, with two prisms and lenses of the most transparent ultra-violet glass, the lenses of 8 in. (203 millimetres) focus, the spectrum from W.L. 8,000 to W.L. 3,000, occupying about 40 millimetres long. Size of plate, 4l by 3i in- The slit is our No. i. This instrument is very suitable for photographs of blood absorption bands, etc. . . 5788T Ultra-violet Glass Spectrograph, as above, same optical design, but lenses of 24 in. (610 millimetres) focus, giving a spectrum from W.L. 8,000 to W.L. 3,000 of about 120 millimetres long. Size of plate, 6J by 4f in. The slit of this instrument is our No. 2 . . £18 10 0 £46 10 0 57891 Quartz Spectrograph, Hilger's, dispersing system one Cornu prism, same design and size as the ultra-violet glass Spectrograph above, giving a spectrum from W.L. 8,000 to W.L. 2,000 of about 65 millimetres long. Size of plate, 4j by 3^ in. . . . . £24 0 0 L 5790 5791 5790T Spectroscope, by Schmidt & Haensch, Kirchhoff-Bunsen pattern, fitted with movable telescope, protecting prism box and millimetre scale, with slit, flint glass prism and oculars Nos. 8a and loa £8 15 5791T Spectroscope, by Schmidt & Haensch, Kirchhoff-Bunsen pattern, with fixed protecting box, telescope with adjusting movement and millimetre scale, fitted with slit, flint glass prism, oculars Nos. 8a and xoa, scale illuminating mirror, etc. . . . . . . £12 CROSS STREET • HATTCW GARDEN, E-C 1050 BAIRD &.TATLOCK (LONDON) LTD. 5792 5792T Spectrometer, with circle of brass 6 in. diameter, divided to half-degrees, reading to one minute by means of a vernier, movable prism table, with vernier divided to half- degrees, collimator, and observing telescope of I in. aperture and 9 in. focal length ; the former is provided with adjustable slit, micrometer screw, and comparison prism ; the observing telescope has a micrometer in addition to rack and pinion movement and illuminating eyepiece 5793T Spectrometer, as above, but smaller in size, with two prisms £12 10 £7 0 57941 Spectroscope, by Schmidt & Hasnsch, direct-vision, Hoffmann's pattern, large model, with micrometer screw-measuring arrangement, prism slit, one each oculars Nos. 78 and QB, tube with millimetre scale, illuminating mirror, small incandescent lamp, etc. . . £19 10 I CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD ^TATLOCK: (LONDON) LTD. 5795-5798 5799 5795T Spectroscope, as suggested by Hoffman, reconstructed model ; with wave-lengths scale, and illuminating mirror for the latter. The telescope is actuated by means of a micrometer-screw for the fine-movement, the latter, however, without measuring drum. Scale-telescope with wave-lengths scale and illuminating mirror . . 5796T Ditto, without scale-telescope 57971 Rack and pinion to the collimator . . . . . . . . . . extra 5798T Stand, with brass pillar on cast-iron tripod, very solid, and elegantly finished with universal joint 57991 Spectroscope, by Schmidt & Haensch, Kirchhoff-Bunsen pattern, large model with micrometer screw measuring arrangement, slit, flint glass prism, ocular No. gb with cross wires and millimetre scale £8 £7 £1 £1 10 £20 15 5801 5801T Spectroscope Stand, mahogany, with burner, suitable for small spectroscopes Nos 5734-5737 • • ..£09 See Halliburton's " Essentials of Chemical Physiology," p. 78. CROSS STREET- HATTCTNT GARDETST, E-.C 1052 BAIRD ^TXTLOCK (LONDON) LTD. THE HILGER WAVE-LENGTH SPECTROSCOPE, 1907 MODEL. The latest form of this spectroscope is shown in Figs. 5802-5807. The telescope and collimator are of II \ in. focal length and i J in. aperture. The prism is of a special form, and may be best considered as built up of two 30° prisms and one right-angled prism from the hypotenuse of which the light is internally reflected, as in Fig. 2. The prism is, however, actually made in one piece. The table on which the prism stands is rotated by means of a fine steel screw, the point of which pushes against a projecting arm on the prism table. To the screw is fixed a helical drum (see Fig. 3} , on which the wave-lengths of the line under observation are read off direct as indicated by the index, which runs in a helical slot. The point of the micrometer screw is of hardened steel, which is finally fixed before the turning of the screw thread is done, to avoid risk of periodic errors ; the cutting of the screw thread being done on this point as one of the centres. This hardened steel point presses against a steel plug in the above-mentioned projecting arm of the prism table and this steel plug is flint hard, and is optically polished. The telescope and collimator are both very rigidly fixed to the cast-iron base, and the whole is screwed to a strong cast-iron tripod. It will be seen that the design is extremely strong and simple ; and the accuracy is as great as that obtainable by the use of the very highest class of divided circle spectroscope (unless recourse is had to careful line-to-line measuiements with a micrometer eyepiece or some similarly laborious process, while in ease, speed, and convenience the " Wave-length " form is vastly superior. Fig. I Fig. 4 Fig. 2 Fig. 5 Fig. 3 5802-5807 5802T Wave-length Spectroscope, prism of 1.65 refractive index for D, accurately calibrated throughout the whole visible spectrum 5803T With denser prism, 1.74 refractive index for D, and correspondingly increased accuracy of calibration Accessories for Use with the above Spectroscopes. 5804T Protective cover to prism table 5805T Camera, with 21 in. focus lens, and tilting for accurately focussing the whole spectrum (shown in position in Fig. 4) 5806T Reading telescope for reading off the drum (by means of a double reflecting prism the figures are not reversed) on raising and lowering stand 5807T Shutter eyepiece with lateral adjustment to bright pointer (see Fig. 5, and description below) NOTE. — The above eyepiece is of very great assistance in the mapping of spectra. By the aid of two shutters, vhich can be shifted in from either side at will in the focal plane to cover any desired part of the field, any bright Bines which by their proximity to feebler lines obscure the latter can be hidden from view. The metal pointer, Evhose point is ground exceedingly fine and polished bright with the greatest care, is illuminated from above with 111 mirror. This bright pointer is adjustable laterally by the two milled head screws below, so that one can always ( eturn to the standard reading by setting the bright pointer on a reference line. £27 10 0 £30 10 0 £0 13 0 £776 £400 £4 12 6 1 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1053 BAIRD &. TATLOCK (LONDON) LTD. Polariscopes, by Schmidt & Haensch. Agents : BAIRD & TATLOCK (LONDON) LTD. DESCRIPTION OF THE POLARISCOPE. In an ordinary ray of light the vibrations of the particles of ether take place simultaneously in all directions perpendicular to its axis. By certain means it is possible to restrict the vibration to any one particular direction. It is then called a linear This conversion of ordinary into polarised light may be brought about first by reflection, which need hardly be considered here, and secondly by repeated single refractions or by double refraction in certain crystals— notably calc spar. In a natural crystal of Iceland spar (Fig. i) the principal axis lies in the line joining the points d and /, where three obtuse angles meet. Suppose a plane to pass through the shorter diagonals of two opposite faces of the rhomb, i.e., either d g, a f, or d b, h f, or d e, c /, it will always contain the principal axis d f. Any such plane, and all planes parallel thereto, are called principal sections of the prism. If a ray of light m n (Fig. 2) falls on one face, as a b dc (of which d b h f represents the principal section), it will, on entering the crystal, divide into two refracted rays unequally bent. Both are polarised, and it will be found that the plane of polarisation (or plane of vibration) of the less refracted or extraordinary ray n q is perpendicular to the principal section d b h /, while that of the more highly refracted or ordinary ray n p coincides with the plane of the section. For polariscopic purposes it is best to give exit to one of the two polarised rays, namely, that one in the direction of the incident light, and to eliminate the other ray. This can be done by converting the calc spar into a Nicol prism. To this end a piece of calc spar is split into an elongated rhombohedron, as in Fig. 3, in which the plane passing through the points abed represents a principal section. The natural ends of the prism a f b e and d g c h, the former of which is inclined to a d and the latter to c b at an angle of 1 7 degrees, are ground so as to reduce their angles to 68 degrees (see Fig. 4). The prism is then divided in the direction b' d', which is perpendicular to a b' and c d', and the halves — after polishing the faces of the section — are united with Canada balsam. The sides are then blackened, and the Nicol is fixed with cork or other suitable material into a brass case. The principal section of the prism passes through the shorter diagonals of the two rhombic ends. If a ray of light / m (Fig. 5) parallel to the edges of the longer side falls on the face a b', it is divided into rwo rays. The less refracted (or extraordinary) ray m p q traverses the film of balsam at p, and emerges in the direction q s parallel to I m. The more refracted (or ordinary) ray m o meets the balsam at o, which, from its being a medium of so much feebler refractive power, causes total reflection of the ray in the direction o r, whereby it becomes absorbed by the case of the prism. The other ray emerges in the direction of the incident ray, but possesses only half of its luminous power. The plane of polarisation (and vibration) of this ray is at right angles to the principal section, and therefore passes through the longer diagonals of the end faces of the prism. Suppose now two Nicol prisms be taken, the one fixed and directed towards a source of light, the other so arranged that it has a movement of rotation about its longitudinal axis. The first prism may be called the polariser ; the second, the analyser. Between the Nicols is placed an empty tube or one filled with water. On looking through the system while revolving the analyser a position will be found in which light no longer passes through. On continuing the rotation of the analyser through half a com- plete revolution another maximum of darkness will be found. For purposes of observation, the points of greatest darkness are to be preferred for reference, since at these points the least movement of the Nicol produces a perceptible change in the appearance of the field of vision. If now the tube be filled with a solution of some substance capable of rotating polarised light such as cane sugar, the analyser having been previously set to darkness, it will be found that the field of vision appears bright, and to obtain the maximum of darkness again the analyser must be turned to the right through a certain angle. Since no rays could pass through when the plane of polarisation of the analyser was at right angles to that of the polariser, it must be concluded that after the introduction of the tube containing the sugar solution the rays have experienced a certain deflection of their plane of vibration. The angle through which the analyser has to be turned to bring about a recurrence of darkness is termed the angle o/ rotation, and is the measure of the deflection experienced by the plane of polarisation. The rotation of the plane of polarisation is called circular polarisation. Substances which exhibit this phenomenon are said to be circular polarising or optically active, and are distinguished as dextro-rotary or laevo-rotary in accordance as to whether they turn the plane of polarised light to the right or left, whilst those substances which do not possess this power are said to be optically inactive. CROSS STREET • HATTQTST GARDEK, E-C 1054 BAIRD &TATLOCK (LONDON) LTD. Light and shade instruments are not, however, sufficiently sensitive for practical purposes, and of recent years a great impetus has been given to polarimetry by the introduction of the half-shadow instruments. In these the mechanism for sensitiveness is arranged so as to produce a field divided into two halves, which in certain positions of the analyser are unequally illuminated, but in one position — capable of being fixed with great accuracy — they exhibit a uniformly faint shade. This position is taken as the zero or point of reference. The half shade is brought about by using as a polariser a half-shade prism of particular construc- tion, or by a semi-disc of quartz as in the Laurent instrument. SPECIFIC ROTATORY POWER. To determine the specific rotatory power of an active substance it is necessary to know— a, The observed angle of rotation in angular degrees. c. The concentration of the solution in grammes per loo cubic centimetres. L, The length of the column of the solution in millimetres. The specific rotation [a] can be expressed by the formula — 10*. a [a]= L. c The value of a varies with the refrangibility of the polarised ray, and it is necessary to state the position in the spectrum of the particular ray employed. There are two systems of expressing the rotation of a substance in general use. In the one it is referred to the D line of the solar spectrum, the rotation being then expressed by [a]D ; in the other it is referred to the " medium yellow ray " (jaune moyen), the colour complementary to Biot's " transition tint," in which case the specific rotation is expressed by [a]j. For the determinations of [a]o the sodium light is employed with aWild, Mitscherlich, Jellet-Cornu, or Laurent instrument, and the direct rotation is found in degrees of arc. The determinations of [alj are made with neutral tint or half-shade polari- meters, such as the Ventzke-Scheibler. The scale divisions in these instruments are arbitary, and require to be converted into angular degrees before the specific rotation can be calculated. Since the readings obtained with such instruments are based on the rotation of a quartz plate, they must of necessity be in terms of the rotation of a quartz plate of definite thickness. Attention may be here called to the fact that the rotatory dispersions of quartz and cane sugar solutions are practically identical. The quartz compensating instrument it will be seen, cannot be used for the comparison of the rotation of substances, having a different power of rotatory dispersion to that of quartz, unless the relation of the rotatory dispersion of the substance under examination to that of quartz is known. The wave length of this mean yellow light is less than that of the ray D, which lies on the border between orange and yellow, so that the numerical value of [n]j is always greater than that of [a]D. Broch has found with a quartz plate I millimetre thick that [a]D = 21.67 degrees and [aj = 24.5 degrees, so that to express one in terms of the other — 24-5 9 [ajj = [a]D = 1.1306 [a]D or approximately = -[a]D 21.67 8 21.67 8 [a]o tz [a]j = 0.8845 [a]j or approximately— -[a]j 24.5 9 The proportion between [a]j and [a]D varies in different substances according to their different rotatory dispersions. Thus for quartz .. .. .. .. .. .. .. [a]D : [a]j =1:1.131 „ solutions of sugar .. .. .. .. .. .. .. [a]D : [ajj =1:1.129 „ alcholic solutions of camphor .. .. .. .. .. .. 1:1.198 „ oil of turpentine . . . . . . . . . . . . . . . . I : 1.243 PRECAUTIONS TO BE OBSERVED IN USING THE POLARISCOPE. Before filling the tube it must either be thoroughly dried by pushing a plug of filter paper or some other soft material through it, or it should be rinsed several times with the solution itself. The cover glasses must also be clean and dry and without serious defects or scratches. Unnecessary warming of the tube by the hand during filling should be avoided : it is closed at one end by the screw or spring cap and cover glass, and grasped by the other end with the thumb and finger. The solution is poured into it until the meniscus projects slightly above the opening, the air bubbles allowed time to rise, and the cover glass pushed hori- zontally over the end of tube in such a manner that the excess of liquid is carried over the side, leaving the cover glass exactly closing the tube with no air bubbles beneath it, and with no portion of the liquid upon its upper surface. The cover glass being in position, the tube is closed by screwing or clamping on the cap as the case may be. The greatest care must be taken in screw- ing down the caps that they do not press too tightly on the cover glasses : by such pressure the glasses themselves may become optically active, and cause erroneous readings when placed in the instrument. It should therefore be ascertained that the rubber washers are in position over the cover glasses, and the caps should be screwed on lightly. Before taking the actual reading, observations are made of the zero and with a standard quartz plate of known rotation. The mean of several readings is taken and corrected for any deviation of the zero. In the polarisation of the quartz plates and colourless solutions, difficulty may be experienced on obtaining a complete correspondence of both halves of the field. This may be overcome and the neutral point found, but when it cannot, the ordinary I eyepiece of the instrument may be replaced by another which is supplied with the polariscope, and which carries a section of a crystal of bichromate of potassium. This removes the difficulty and renders it possible to obtain a field of exact neutrality. The instrument claiming most attention at present, and which on account of its increased accuracy over the half-shadow ; arrangement has a great future before it, is the one in which the optical field is divided into three parts. It gives the greatest satis- faction to those who use it, and the zero point remains constant after many months of continual usage. For those who intend purchasing an instrument for general sugar work, or, in fact, for all work in which substances are examined which have a rotatory dispersive power equivalent to that of quartz, we strongly recommend this new polariscope. Messrs. Schmidt & Haensch have also made certain improvements in instruments which are to be used in tropical climates, i whereby the prisms are protected from excessive weathering. With ordinary care, however, any polariscope should be able to withstand a tropical climate. The new form of tube which allows the presence of a small bubble without interfering with the reading, will be found very useful for volatile liquids. It is a decided improvement on the tube which had an enlargement in the centre. The modified form of polarimeter described by H. Landolt (Ber., 1895, 28, 3102-3104) is admirably adapted for scientific purposes. Its construction is similar in principle to the instrument described in 4230 ; it is, however, much cheaper. It also .facilitates the examination of rotatory liquids at temperatures extending over a wide range. ^; 1 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1055 BAIBD &WLOCK. (LONDON) LTD. 5808-5809 5808* with one £11 £11 15 15 Polariscope, half-shadow, Mitscherlich, with divided circle reading to o.ic each patent tubes 100 and 200 millimetres long, and gas lamp 5809T Polariscope, as above, with two tubes 94.7 and 189.4 millimetres long This is a cheap form of polariscope which has been specially designed for the estimation of sugar and albumen in urine. Behind the analyser is a small telescope, and behind the polariser a semicircular plate of quartz. The telescope is focusse on to this plate, and the field of vision appears as a circle divided into two halves as shown in the figure above. A pointer i attached to the analyser, which moves to the right or left on a metal disc divided into angular degrees. A vernier upon whic ten divisions correspond to nine divisions of the disc enables the observer to read tenths of an angular degree estimate twentieths. In the annexed figure the zero point of the vernier is not quite at 3° on the scale of the disc, and the eighth division of 1 vernier is the only one which coincides with a division of the scale — consequently the reading is 2.8°. The instrument is constructed for homogeneous light. A sodium lamp must therefore be used as the source of illumination The zero point, as in other half-shadow instruments, is found when both halves of the field are of the same tint. The tube filled with the liquid to be examined is placed in the instrument, and after having focussed the plate by means i the telescope, the pointer is turned to the right or left according to whether the solution is dextro or laevo rotatory, until both halves of the disc are again equally tinted. If the instrument is to be used for general work, a tube of the length of 200 millimetres is supplied, and another of too milli- metres for dark coloured solutions, but when used exclusively for urine it is more convenient to have one of 189.4 millimetres, and another of half that length. These tubes give at once the percentage by volume of sugar and albumen, each degree being equal to i gramme in 100 cubic centimetres. Albumen polarises to the left to the same extent as glucose does to the right. The estimation of sugar and albumen in urine is effected in the following manner : — -The urine, if necessary, is filtered. Should it be too dark coloured to be read in the long tube, the short one is tried, and if still too dark, some extracted animal charcoal is added, and the whole well shaken. In the event of this not effecting decolorisation, 100 cubic centimetres of the urine is intro- duced into a flask graduated to contain 100 and no cubic centimetres, basic acetate of lead is added to the no cubic centimetre mark, the mixture is then shaken and filtered, and the reading multiplied by o.i i to correct for dilution. The temperature should be 15° to 20° C. If the urine is free from albumen the reading corresponds to the percentage of sugar. Should it contain albumen, a few drops of acetic acid are added to 100 cubic centimetres boiled, cooled, filtered, and made up again to volume at 15° to 20° C. EXAMPLES. 1. A clear urine free of albumen read 3.1° in the 189.4 millimetre tube. Sugar = 3.i per cent. 2. A clear urine free of albumen read 1.6° in the 94.7 millimetre tube. Sugar = 1.6x2 = 3.2 per cent. 3. Urine brown, no albumen, taken 100 cubic centimetres+io cubic centimetres lead solution, tube 189.4 millimetres. Reading 2. 8, sugar 2.8x0.11 = 3.08 percent. 4. Urine brown, no albumen, taken 100 cubic centimetres+io cubic centimetres lead solution, tube 94.7 millimetres. Reading 1.4, sugar 1.4x2 xo.n = 3.o8 per cent. 5. Urine slightly coloured with albumen — tube 189.4 millimetres. (a) Direct reading 0.6° (b) After removal of albumen reading o°. Therefore sugar o per cent., albumen 0.6 per cent. 6. Urine clear, slightly coloured, containing albumen — tube 189.4 millimetres (a) Direct reading 2.6°. (b) After removal of albumen 3.1. Therefore sugar 3.1 per cent. Albumen 3.1—2.6 = 0.5 per cent. CROSS STREET • HATTON GARDEN, E- C 1056 BAIRD &TATLOCK (LONDON) LTD. 5810r Polariscope with simple quartz wedge compensation and reduced scale of 0-35° Ventzke, for direct reading of beet sugar percentages, without dust protector, with two glass tubes of 200 millimetres, in wooden case .. .. .. .. .. .. £16 15 0 5811T Polariscope as above for 400 millimetre tubes, with two glass tubes of' 400 millimetres, in wooden case .. \. .. .. ".. .. .. .. £18 10 0 Lamps for above extra, see Nos. 5855 to 5862. 5812 5812T Polariscope, Schmidt & Haensch, with wedge compensation and Jellet-Cornu polariser, with dust protector and illuminating mirror for scale, for direct reading of sugar in urine, etc., with one each tubes 50, 100, and 200 millimetres. Price, on tripod base, with mahogany case £18 18 0 Lamp ior above extra, see Nos. 5855 to 5862. I CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1057 I \2?!&^ v*«-^i,' BAIRD &TATLOCK (LOM)ON) LTD. 5813 5813' Polariscope with quartz wedge compensation and Jellet-Cornu polanser, without dust protector for the quartz wedge compensation, with scale for direct reading of sugar in urine to o.i per cent., with one each observation tubes, 50, 100, and 200 millimetres, and mahogany case £16 17 Lamps for above, see Nos. 5855-5862. 5814-5815 5814T Polariscope with simple quartz wedge compensation and reduced scale of 0-35° Ventzke, for direct reading of beet sugar percentages, with dust protector and two glass tubes of 200 millimetres, in wooden case . . . . . . . . . . . . £19 17 6 581 5T Polariscope as above, for 400 millimetre tubes, with two glass tubes of 400 millimetres, in wooden case . . . . . . . . . . . . • . . . . £20 17 6 Lamps for above, see Nos. 5855-5862. CROSS STREET • HATTOTST GARDE1ST, E-C 1058 BAIRD &TATLOCK (LONDON) LTD. Fig. I. 5816 5816' Polariscope, Schmidt & Haensch, Lippich's model half-shadow, with divided circle, reading by magnification to 0.01°, mounted on pillar with iron tripod base, with one each tubes 100, 200, and 220 millimetres, with gas burner for sodium flame, in case £32 15 0 INSTRUCTIONS FOR THE USE OF THE HALF-SHADOW POLARISCOPE, LIPPICH'S SYSTEM (Fig. 5816). In the above illustration p indicates the telescope, II the magnifying glasses, with protection cap and reflecting mirrors, K the graduated dial, St the analysing Nicol prism, which is fixed to the revolving graduated dial and to the telescope, and h the movable polariser, with the graduated segment A of a circle fixed to it, and B a little tube for bichromate solutions. The apparatus can only be used with a sodium flame, and a suitable sodium lamp is supplied with it. The latter is placed at a distance of 22 centimetres from the apparatus. It consists of a Bunsen burner (or a Barthel's spirit burner) supplied with a platinum ring on which some pulverised sodium chloride is placed, and made intensely incandescent by means of the non- luminous flame from the burner ; then the apparatus is pointed towards the brightest part of the yellow flame, which can easily be accomplished by means of the adjuster provided with the lamp. The graduated dial, which is made to revolve by means of St with hand or by the micrometer screw m, after the pinch k has been fixed, is as a rule graduated all the way round. In addition to whole degrees, half and quarter degrees are indicated on the dial ; 24 such quarter degrees are divided on the two verniers into 25 divisions, therefore a scale mark on the vernier coinciding with any one scale mark on the dial would indicate 0.01°. Fig. I shows the inner revolving dial and the exterior vernier ; the zero line of the vernier is now between the 13.50 and the 13.75° line of the dial ; the 0.16 of the vernier coincides with some line on the dial, therefore the total reading is 13.50+0.16 = 13.66°. If desired, a second scale can be provided on the dial to show directly grape or beet sugar percentages. This is done by dividing the dial into whole percentages ; nine such are divided on the vernier into ten divisions, so that the vernier reads to one- tenth per cent. The reading is done in the same manner as described above ; the beet sugar scale is based on the standard weight of 26.048 grammes. The 100 line (100 per cent.) corresponds with a solution of 26.048 grammes of chemically pure sugar in a 100 cubic centimetre flask, examined with the 200 millimetre tube. The grape sugar scale is now rarely used, but if a tube of a certain length (according to the most recent researches 189.4 millimetres) is used in connection with the degree scale, the grape .sugar percentages can also be found directly, one degree in this case corresponding exactly to one per cent, of grape sugar. The Adjustment. — When the above apparatus is well illuminated by the sodium flame, the zero position (the starting point of all experiments) must first be found : this is indicated by the two halves of the field appearing equally illumined (equal half- shadows). For this purpose the telescope F is focussed on the Lippich's polariser, so that the field presents a perfectly clear, round circle divided into two equal parts by a sharply defined vertical line. If the graduated dial is turned through three or four degrees to either the right or the left of the zero line, it will be seen that one-half of the field will become lighter, the other half darker. In the first place, the zero position is so adjusted that the zero line of the circle coincides with the zero line of the vernier. The half-shadow can now be made lighter or darker (according as the polariser is turned to the right or left of the zero line) by Iraeans of the pointer reaching from the dial-segment. When the pointer h is in the zero position, and at the same time the analyser JA is placed in the zero position, both halves of the field of view appear black. The nearer the pointer is to the zero line, the darker the half-shadow will become, and the more sensitive the apparatus ; but when the solutions are not quite transparent, the pointer j-nust be moved more or less away from the zero line, so that the field is clear. For the majority of experiments the position of j:he pointer at 7^° is most suitable, therefore the apparatus is usually so adjusted that in this position the dial and vernier read : xactly o. When the pointer is moved, of course the zero point of the apparatus changes, and no longer corresponds with the ,^ero line of the dial. The difference between the latter and the zero position of the apparatus must either be taken into account I the simpler way) , or else after the graduated dial has been moved to o the apparatus must be again placed in the zero position ; Ito do this, the analysing Nicol prism is turned, by means of the screws A, to the right or left until the half-shadows are equal in tint. Special attention must be called to the following circumstance, which, if not noted, may lead to considerable confusion. When the circle has been turned too far, and has gone beyond the sensitive range of the apparatus, the light, on comparison, to a certain extent of the same intensity on either side of the vertical line, and this point maybe mistaken for the zero i. Under these circumstances, even if the circle is turned through 10, 15, or even a greater number of degrees, hardly my change will be observed. It is a matter, therefore, of the greatest importance, particularly after the sample to be examined has been placed in the |ipparatus, to see that when the circle has been turned a few degrees on either side of the zero line, the transition from light to hade, and vice versd, is instantaneous. On placing the sample to be tested within the apparatus, the first thing to do is to accurately adjust the telescope so that he field is quite clear and equally divided by the vertical line, then the circle is turned until the shades are exactly of the same ptensity on either side of the line. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 105'J BAIRD &TATLOCK (LONDON) LTD. 5817-5818 58171 Polariscope, Schmidt & Haensch, half-shadow, with improved reading scale, suitable for sugar analysis, supplied with one each tubes 100 and 200 millimetres, on tripod stand, for use with oil, gas lamp, or electric light in mahogany case Lamp for use with above extra, see Figs. 5855 to 5862. 5818T Polariscope, exactly as above, but adapted for tubes up to 400 milli- metres, with one each tubes 100, 200, and 400 millimetres, with tripod base as figured, in mahogany case Lamp for use with above extra, see Figs. 5855 to 5862. 5819T Polariscopes as above, fitted with new triple field arrangement Price, speciall' adapted tori in the tropics £27 0 0 £27 17 6 £30 10 0 £31 7 6 extra £576 5820 5820T Electric Light arrangement for Polariscopes 582 1T Three Cell Accumulator in case with switch, etc. .. 58221 Polariscopes as above, with new pattern resistance lamp Lamps for oil and gas, etc., see Nos. 5855 to 5862. extra £5 17 6 £400 £250 CROSS STREET • HATTCTK GARDETST, E-C 1060 BAIRD &. TATLOCK (LONDON) LTD. DESCRIPTION OF POLARISCOPES Nos. 5817-5825. This instrument is known as the half-shadow apparatus of Schmidt & Haensch. The tube v contains the illuminating system of lenses and is placed next to the lamp ; the polarising prism is at P (known as a Jellet-Cornu prism, and which produces the half-shadow effect) and the analysing prism is contained in G. The quartz wedge compensating system is also contained in G, and is controlled by the milled head x. The tube F carries a small telescope, through which the field of the instrument is viewed, and just above is the reading tube L, provided with a mirror and magnifying lens for reading the scale. The tube containing the solution under examination is shown in the trough between the two ends of the instrument. In fusing this polariscope the lamp (ordinary white light) is placed at a distance of at least 20 centimetres from the end ; the observer is so seated that the eye is in line with the tube F. The telescope is properly adjusted when the field of vision appears as a round luminous disc divided into two halves by a vertical line passing through the centre. If the milled head T be rotated the appear- ance of the field changes, one half becoming dark, the other half light, and finally a point will be found when the field is neutral , or of the same intensity of light in both halves. The three different appearances presented by the field are shown in the following diagram : — When the milled head is set at the point which gives the appearance of the middle disc as shown above, the eye of the observer is raised to the reading tube L and the position of the scale with regard to the zero noted. It will be seen that the scale proper is attached to the quartz wedge which is moved by the milled head : attached to the other quartz wedge is a small scale called a vernier, which is fixed, and which serves for the exact determination of the movable scale with reference to it. On each side of the zero line of the vernier a space is divided into ten equal parts. By this device the fractional part of a degree indicated by the position of the zero line is ascertained in tenths : it is only necessary to count from zero, until a line is found which makes a continuous line with one on the movable scale. With the neutral field, the zero of the scales and the vernier should coincide, otherwise the zero point is out of adjustment. If, however, there is a deviation, a neutral field is secured at this point by turning one way or the other the small key provided with the instrument, and which fits into a nipple on the left-hand side of F, the fixed quartz wedge of the compensating system. Care must be taken not to confound this nipple with a similar one on the right hand of the analyser, as the adjustment of the instrument would be seriously disturbed by moving it. Unless the deviation be greater than 0.05 degree, it is enough to note the amount and make the necessary correction. The " setting " of the zero having been performed, the determination of the accurate adjustment of the instrument by means of the control quartz plates is proceeded with. Three such plates should be used which have " sugar values " approximately 80, go, and 100 degrees respectively. These values may vary with the temperature, and tables are furnished with them which give their exact value from 10° to 35° C. If one of these plates be placed in the instrument it will be noticed that the uniform appearance of the field is changed. The milled head is turned to the right until the exact point of neutrality is re-established. The average from several such readings is corrected for the deviation of the zero point, provided any was found, the deviation being added if it was to the left, and sub- tracted if to the right. If the adjustment of the instrument be correct, the result should be the value of the control plate used as ascertained from the table of the temperature at the time of observation. Each of the three plates is read in this way. The complete verification of the accurate adjustment of the polariscope as described above should be employed whenever it is set for the first time, whenever it has sustained any serious shock or injury, and whenever it has been transported from one place to another. It should also be done at least once a week when the instrument is in constant use. This instrument is adapted for use with white light illumination from oil or gas lamps. It is convenient and easy to read, requiring no delicate discrimination of colours by the observer, and can be used by a person who is colour blind. This form of instrument is adjusted to the Ventzke scale, which is defined to be such that I degree of the scale is the yJT part of the rotation produced in the plane of polarisation of white light in a column 200 millimetres long by a standard solution of chemically pure cane sugar at 17.5° C. ; the standard solution of cane sugar in distilled water being such as to contain at 17.5° C. in 100 cubic centimetres, 26.048 grammes of cane sugar. Ventzke degrees can be converted into angular degrees of D light by multiplying by a factor which according to Rimbach for cane sugar is 0.344. F°r instance, if a solution of a sugar read 45.6° Ventzke, then 45.6 X .344 = 15.46 angular degrees. This form of instrument only gives accurate results with solutions having the same dispersive power as quartz : it is fairly accurate for the carbohydrates generally, but for substances such as terpenes, tartaric acid, etc., the readings would be useless. 1061 BAIRD &WLOCK (LONDON) LTD. 5823-5825 5823T Polariscope, Schmidt & Haensch, half-shadow, with improved reading scale, suitable for sugar analysis, with one each tubes 100 and 200 millimetres, on Bock stand, for use with oil, gas lamp, or electric light Lamps for above extra, see Nos. 5855 to 5862. 5824T Polariscope, exactly as above, but adapted for tubes up to 400 milli- metres, with one each tubes 100, 200, and 400 millimetres Lamps for above extra, see Nos. 5855 to 5862. 5825T Polariscope, exactly as above, but adapted for tubes up to 600 milli- metres, with one each tubes 100, 200, 400, and 600 millimetres Lamps for above extra, see Nos. 5855 to 5862. 5826T Polariscopes as above, fitted with new triple field arrangement 5827T Polariscopes as above, fitted with new electric light arrangement, Fig. 5820 5828T Three Cell Accumulator in case with switch, etc. . . 5829T Polariscope as above, with new pattern resistance lamp Lamps for oil and gas, etc., see Nos. 5855 to 5862. Glass Cases for above, see No. 5830. £28 0 0 £31 10 0 Price, special adapted for use in the tropi £28 17 •' £32 7 6 £33 10 0 £34 7 6 extra £576 £5 17 6 £400 £250 CROSS STREET • HATTON GARDETST, E-C 1062 BAIRD &TATLOCK (LONDON) LTD. 5830 5830T Case, glazed, with wood base, for covering polariscope and lamp, suitable for polariscope Nos. 5823-5825. For polariscope to hold tubes up to 200 400 600 millimetres. £5 10 0 £5 10 0 £6 10 0 5831-5832 5831T Polariscope, by F. Schmidt & Haensch, specially adapted for beet sugar analyses, with linear scale and large circle with magnified divisions, two reflecting mirrors for convenient reading of the scales, on Bock stand with two tubes of 200 millimetres, without case 5832T Polariscope, by F. Schmidt & Haensch, as above, with two tubes of 400 millimetres, without case . . 5833T Glass case, with base, for above, see Fig. 5830 . . . . . . . . extra Lamps for above, see Nos. 5855-5862. £31 0 0 £33 10 £5 10 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1063 —i BAIRD &TATLOCK (LONDON) LTD. Polariscope. Double Compensating Instrument. 5834-5836 5834T Polariscope, F. Schmidt & Haensch, with half-shadow double- wedge compensator, for use with tubes 100-200 millimetres, with two tubes 100 and 200 millimetres long, and with dust protector for analyser. Price, on Bock stand, with glass case, Fig. 5830 Lamp for above extra, see Nos. 5855 and 5862. 5835T Polariscope, as above, for use with tubes 100-400 millimetres, with three tubes 100, 200, and 400 millimetres long. Price, on Bock stand, with glass case, Fig. 5830 Lamp for above extra, see Nos. 5855 to 5862. 58361 Polariscope, as above, for use with tubes 100-600 millimetres, with four tubes 100, 200, 400, and 600 millimetres long. Price, on Bock stand, with glass case, Fig. 5830 Lamp for above extra, see Nos. 5855 to 5862. 58371 Triple field arrangement, fitted to any of above Polariscopes extra Prices, special! adapted lor Ui in the tropics. £42 0 0 £42 17 £45 0 0 £45 17 £50 0 0 £50 17 6 £576 This instrument has within recent years come into very general use as a saccharimeter. It shows a divided disc of a uniformly yellowish grey colour when set at zero, the halves rapidly changing to dark or light when an optically active solution is introduced. It carries a saccharimetric scale showing direct percentage of sugar like the Ventzke- Schcibler, and is used with ordinary instead of monochromatic light. The various parts of the instrument are very similar to the one previously described, the exception being the arrangement of the compensating system. In the previously described instrument a pair of quartz wedges and the compensating plate are necessary, whereas in this instrument there are two pairs of quartz wedges, the compensating plate being replaced by a pair of quartz wedges of exactly similar proportions to the first pair, but having an opposite rotation. One of these pairs of wedges is immovably fixed in the instrument, whilst the other is horizontally movable at right angles to the axis. By such arrangement the instrument is rendered extremely sensitive. CROSS STREET • HATTOlsT GARDETST, E-C 1064 BAIRD &TATLOCK (LOM)ON) LTD. A MODIFIED FORM OF POLARIMETER FOR SCIENTIFIC PURPOSES. This apparatus, which has been fully described by H. Landolt (Ber., 1895, 28, 3102-3104), is similar in principle to Landolt's apparatus with a Lippich polariser. This new instrument, which is fitted with a triple field polariser, is made to take tubes not more than 220 millimetres long. The following illustration will explain its construction : — 5838T 5839T 5840T 5838 Polariscope, Landolt's, half-shadow, with divided circle, Lippich's triple field polariser, graduated to read to 0.01°, to take tubes up to 220 millimetres long. Price, with tubes 100, 200, and 220 millimetres on Bock stand Landolt's Gas Lamp, for sodium flame . . . . . . . . . . extra Landolt's Heating Apparatus, G, for 100 cm. tube, with thermometer, asbestos cased jacket, so that tube can be heated while under observation . . . . extra The metal jacket is made so that the observation tube may be heated, or a convenient freezing mixture may be introduced. For such experiments only a 100 centimetre tube can be used, as there are arrangements at each end for preventing the deposition of moisture on the outside of the glasses of the tube. The inner surface of the tube is gilded, and a vertical tubular limb of small bore allows for the contraction or expansion of the contents of the observation tube. The analyser is controlled by the simple lever c and a micrometer screw for fine adjustments ; the scale 6 is divided into degrees, and the readings are accurate to o.oi degree. The instrumen t is constructed for homogeneous light. £39 10 £3 13 0 0 £3 15 0 Fig. E. DESCRIPTION OF HALF-SHADOW APPARATUS. Fig. E shows the parts of an apparatus for the determination of specific rotatory power. (F. Lippich upon " Polaristrobometric Methods, with especial reference to the Half-Shadow Apparatus," Sitzungsber. d. k. Akad. d. Wiss. Wien. Math.-naturiv.Klassc, | 1885, 91, Ila, 1059-1906 ; also O. Schonrock, " Apparatus and Methods for the Estimation of Specific Rotation," Part IV. in H. Landolt's work, Das optische Drehungsvermogen, 2nd edition, 1898. Brunswick, F. Vieweg & Son.) The diaphragm A1 and the lens K are portions of the illuminating arrangement ; the lamp is situated near the diaphragm A1. The Nicol prisms N, and N,, together with the diaphragm D, comprise the polariser. The diaphragm A, the Nicol prism N,, and the small astronomical telescope Q R form the analyser' CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1065 BAIRD &TATLOCK (LONDON) LTD. The direction of the oscillations of the light coming through N, and N, form a small angle with one another, the so-called half-shadow. When the oscillations of light coming through the Nicol N, are nearly perpendicular to the bisecting line of this angle, the observer sees both halves of the diaphragm D equally illuminated. This is the zero point of the apparatus. To determine the specific rotatory power of a substance, a plane-parallel layer of it is placed between the diaphragms D and A ; liquid substances are placed in tubes which are closed with glass plates. For an apparatus with circular divisions (polarising apparatus) the Nicol prism N, and the tube o R is rotated until both halves of the optical field are equally illuminated ; this apparatus requires homogeneous light. With a quartz wedge compensat- ing apparatus (saccharimeter) , the rotation of the active substance is compensated by a corresponding rotation of a quartz plate ; for such instruments white light is used. It will be seen that the stand, and more especially the arrangement for reading the scale and vernier, is considerably simplified, as compared with the first and older form of this instrument (loc. cit.). The apparatus consists of a tube support D, at one end of which is the circular scale R and the different eyepieces, whilst at the other end is the triple field polariser p. H is an arrange- ment for altering the intensity of the light passing through the polariser. cc are two parallel triangular shaped runners, fixed on to D, for taking the platform T. The screw q raises or lowers the platform T, so that the observation tube may be brought into the optical axis. The parallel runners cc serve as a base for supporting the rectangular metal jacket G, to be used if observations are to be .taken through wide ranges of temperature. APPARATUS FOR ILLUMINATION. Hitherto saccharimeters have been illuminated in the following way. A lens fitted to the lamp caused the rays of light to emerge in a parallel state. A system of two lenses projected an image of the flame about midway between the polariser diaphragm (D in Fig. E) and analyser diaphragm (A in Fig. E). With this arrangement the intensity of the light is unequal ; thus, with a small Auer lamp, the polariser diaphragm is generally not uniformly illuminated, whilst any displacement of the ordinary large flame lamps quite appreciably alters the zero point of the saccharimeter. F. Lippich has surmounted these difficulties by employing a lens K (Fig. E), which projects the li^ht into the diaphragm of the analyser A. All new instruments made by the firm of Schmidt & Haensch are provided with an illuminating lens of such a focal length that the source o/ light must be at least 14 centimetres distance from the lens. LIPPICH POLARISER (half natural size). Fig. F represents a Lippich polariser, with the Nicol prisms N4 and N, and the illuminating — lens K,. With this arrangement any convenient source of light may be used, such as spectro scopically analysed light or electric light. Fig. F. 5841 58411 Pmnrr,8tCOiPe' I' Schmidt.& Haensch, with double quartz wedge compensator and i on heavy cast-iron stand, provided with fittings for five observation tubes &?±»4±S*2L ^^'A*4* -ith a second microscope, " so Lamps for above, Nos. 5855 to 5862. £143 10 0 CROSS STREET • HATTCrNT GARDEN, E-C 1066 BAIRD &.TATLOCK (LONDON) LTD. A58411 Polariscope, F. Schmidt & Haensch, after designs of Dr. Herzfeld, and as supplied to the laboratories of the German sugar industry. Fitted with double quartz wedge compensator, well protected by metal case, and mounted on heavy cast- iron base. The instrument is fitted with revolving drum, and arranged for five observation tubes for continuous polari- sation, and thus by means of a slight movement a second tube can be brought in front of the telescope, thus permitting quick successive tests. The single tubes are numbered so that each test can be readily brought in front of the observation distance tube as required, the tubes being so placed that any shaking of the liquid is prevented. Price, adapted to take tubes up to 600 millimetres long One Case for storing above, with glass side, No. 5830 One Lamp as No. 5856 (for other lamps see Nos. 5855-5862) One set of 15 tubes, 5 each 200, 400, 600 millimetres long Price of complete outfit £143 0 0 £6 10 0 £180 £10 0 0 £160 18 0 5842 >842T Polariscope, half shadow, by F. Schmidt & Haensch (Landolt's Apparatus with Lippich's Polariser), of newest construction, with large silvered circle divided in o°, reading by verniers and magnifiers to 0.01°, and dust protector for the circle, with one each observation tubes (water jacketed) of 400, 300, 200, and 100 millimetres long, in glass case . . £95 0 0 8431 Landolt's Sodium Gas Lamp, suitable for above .. .. .. .. £3 15 0 844T Polariscope, as No. 5842, fitted with triple field, specially adapted for use in the tropics and with Landolt's sodium gas lamp . . . . . . . . • • £106 0 0 The polariser consists of a fixed Glan Nicol which occupies the entire field, and a movable Nicol filling only ic-half of the field. By rotating this latter Nicol the brightness of the penumbra may be regulated. While e sodium light only can be used with Laurent's polariscope, with this instrument any kind of homogeneous light ay be employed. There is an arrangement allowing two tubes to be used at the same time, and by means of the lever M one or .her can be brought into the field if desired. The instrument is very sensitive, the scale is capable of being read to 31°, and since it can be used for the determination of magnetic rotation, it is stated to be specially adapted for .entific purposes. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1067 €PT 5855 5855- Gas Lamp, with metal cylinder and lens for polariscopes 5856' Incandescent Gas Lamp, on stand, height adjustable 5856 5857 58571 Argand Lamp 5858* Petroleum Lamp, with asbestos chimney, for polariscopes 5858 £1 7 £1 14 CROSS STREET • HATTON GARDETST, E-C 1068 BAIBD <XTLOCK (LOM5ON) LTD. 5860 60T Petrol Lamp with round burner and asbestos chimney blT Spirit Incandescent Lamp with asbestos chimney . . 5862 5861 5i>2T Acetylene Lamp with chimney and acetylene gas generator £1 10 0 £2 10 0 £5 17 6 1069 BAIRD &TATLOCK. (LONDON) LTD. A5862' Special Osram Lamp. The lamp requires 1.5 ampere, and burns at 6 volts. A lamp is provided with the electric illuminating apparatus The above lamps can be connected in series with a twenty-five candle power glow lamp on a lighting main, or can be run off three accumulators. The lamps have, owing to their low consumption of current, at least 100 burning hours. It is desirable only to send the current through the lamps during charge and discharge, and a switch will fore be required lor each accumulator. 5863-5864 5863T New Electric Light Arrangement adapted to Polariscopes Nos. 5834 to 5837 . . extra 58641 New Electric Light Arrangement as above, with three cell accumulators in case with switch ACCESSORIES FOR SCHMIDT & HAENSCH POLARISCOPES. A NEW FORM OF OBSERVATION TUBE. 5865 It is not necessary to completely fill the tube before placing the glass cap on. The small bubble of enclosed air collects at a, and in no way interferes with the reading. The tube must be filled at the narrow end, and when the cap is on it should be inverted, so that the bubble may collect at the widened end. Such tubes are well adapted when acid and volatile solutions such as ether, chloroform, alcohol, etc., have to be dealt with. 5865' Polariscope Tube, complete, with brass screw caps at ends. 50 94.7 100 189.4 200 220 400 121- llj- 12/- 121- 12/- 12/- 131- £076 £5 17 £9 17 600 millimetres long. 15/- each. 5866 5866T Ordinary Observation Tubes, glass, mounted, with glass covers and rubber rings, brass screw ends. 25 50 94-7 ioo 189.4 200 22O 400 600 millimetres long. 101- lOj- 101- 101- 101- 101- 10/- 111- 13f- each. UP) 14 -CROSS STREET"- HATTO^ GARDETST, E-C-" HI 1070 BAIRD &TATLOCK (LONDON) LTD. 58671 Ordinary Observation Tubes, brass, nickel-plated. 25 50 94.7 100 189.4 200 220 400 121- 121- 12/- 12/- 12/- 121- 121- 13/- 600 millimetres long. 15/- each. 5868 5868T Inversion Tubes of glass with aperture for thermometer, and brass covering for water jacket. 50 100 200 220 400 600 millimetres long. 251- 251- 26/6 28/- 30/- 35/- each. 5869 5869T Inversion Tubes of glass with aperture for thermometer and brass covering for water jacket, provided with glass stopper and thermometer. 100 200 400 600 millimetres long. 531- 54j- 58J- 60/- each- 5870 587 0T Pellet Observation Tubes, with inlet and outlet tube for continuous flow of water. 100 200 400 millimetres long. 231- 23/- 24j- each. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1071 \Z7K7 BAIRD &TATLOCK (LONDON) LTD. K 5871 58711 Control Observation Tubes of adjustable length, adjustable from o to 210 respectively, 210 to 420 millimetres . . . . ... • • • • • • - - £77 58721 Thermometer, with a range from 10° to 32° C. in tenths, for use with inversion tubes . . £08 5873T Glass Discs or Covers for ordinary tubes (Fig. 5866) . . . . . . per doz. £0 5 58741 Glass Covers for patent tubes (Fig. 5865) . . . . . . . . „ £06 5875T Rubber Rings for ordinary tubes (Fig. 5866) . . ,,£01 5876T Rubber Rings for patent tubes (Fig. 5865) .... ,,£01 5877T Normal Weights for polariscope, 26.048 grammes . . . . . . . . each £0 3 5878? Normal Weights „ 13-024 „ . . . . . . . . „ £02 5879* The above two weights in one case . . . . . . . . . . . . £06 5880T Normal Weights, new form, 26 grammes . . . . . . . . . . each £0 5 5881T Normal Weights, „ 13 „ . . . . . . . . . . „ £03 5882* The above two weights in one case . . . . . . . . . . ..£09 5883T Normal Quartz Plates in brass fittings of 25° to 100° Ventzke, turning at right angle for controlling saccharimeters, according to the Physikalisch Technischen Reichsanstaldt £2 7 5884T Normal Quartz Plates in brass fittings, — 25° to + 25° . . . . . . . . £33 5885T Nickel Basin, with brass counterpoise for weighing sugar . . . . . . each £0 7 5886T Nickel Funnel for filling same .. .. .. .. .. .. ,, £05 58871 Nickel Basin, with cover for dry substance determination . . . . . . . . £036 Schmidt & Haensch's polariscopes and accessories not described in foregoing pages obtained specially to order. -CROSS STREET • HATTOTST GARDETST, E-C 1072 BAIRD &TATLOCK (LONDON) LTD. Polariscopes, Laurent's. 5888 5889 • 4 5888T Saccharimeter and Polariscope, for use with sodium flame, with two divisions, small model, for tubes of 20 and 22 centimetres long .. .. .. .. ..£1600 5889T Gas burner with two jets for above . . . . . . . . . . ..£240 5890r Three metal tubes, 20 centimetres long, for above . . . . . . . . . . £1 13 0 Price complete £19 17 0 5891T Saccharimeter and Polariscope, for use with sodium flame, grand model for diffusion, for tubes of 50 centimetres long and cover 58921 Gas burner with two jets 58931 Four glass tubes cased in brass, 20, 30, 40, and 50 centimetres long £19 16 0 .. £240 .. £3 17 0 Price complete £25 17 0 NOTE. — Please indicate the pressure of the gas when giving an order. rner for Sodium Flame, with two jets suitable for low gas press of water 5895T Gas Burner for Sodium Flame, with one jet suitable for high pressure 5894r Gas Burner for Sodium Flame, with two jets suitable for low gas pressure, under 0.025 metre of water £240 £1 10 6 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK. (LONDON) LTD. 5896 5896 5896T Spirit Lamp. If there is no gas, or if the pressure is feeble and irregular, or if there is only gas during some months of the year . . • • • • • • • • • • »* 1 5897 58971 Saccharimeter and Polariscope, grand model for diffusion, for tubes of 50 centimetres long, for use with ordinary white light 5898T Set of four glass tubes cased in brass, 20, 30, 40, and 50 centimetres long 5899T Glass Tubes cased in brass, for Laurent's Polariscope. For sugar and acid liquids they are more easily cleaned, and are preferable. Length . . . . 20 22 30 Price .. .. 17/- 18/9 20/6 59001 Brass Tubes for Laurent's Polariscope. Length . . . . 20 22 30 Price .. 13/9 14/6 15/6 590 1T Plate of standard quartz of o.ooi metre thickness 5902T Buisson's tables calculated on actual normal weight, 16.29 grammes 5903T Platinum wire spoons 5904T Glass discs or end covers for tubes . . 5905T Tube for invert sugars, 22 centimetres, brass case with thermometer tubulure 5906T Thermometer for use with above . . £24 £3 15 17 40 23/- 40 17/- 50 26/- 50 18/9 cm. each. cm. each. (price variable) each £2 £0 £0 £0 £1 £0 4 4 7 1 13 7 0 0 6 2 0 9 CROSS STREET • HATTOTST GARDEN, E-C 1074 BAIRD &.TATLOCK (LOM)ON) LTD. Laurent's Saccharimeter and Polariscope. DESCRIPTION OF THE APPARATUS. GAS BURNERS. Two burners are constructed, one for high and one for low pressure, and it is necessary to indicate which is required when ordering. To measure the pressure of the gas take a glass U tube and half fill it with water. One limb is open and the other is connected with a gas tap, and on opening this the gas causes the water to descend in one limb and ascend in the other ; the difference of level is the pressure of the gas. GAS BURNER OF HIGH PRESSURE (Fig. 5889, page 1073). This burner is employed when the pressure is more than 25 millimetres of water. It has one or two jets. The figure represents the flame full size, the supports only being slightly reduced. A. Large yellow flame of low illuminating power. B. Luminous part, very -intense. It is on this that the saccharimeter is directed. It is only to be obtained by Laurent's burners and lamps, c. Chimney. The flame is composed of two parts, the one H, violet, high, large and very hot, the other D, a cone not so hot ; it is blue in the gas burners and violet in the spirit lamp. The spoon consists of a platinum gauze cup G soldered to a strong platinum wire F, which is fixed in the corner at the base of the chimney by means of a pin p and retained by a chain. It is easily replaced. The salt is placed in the cup G ; when it melts it ascends by capillarity to t!he edge, which is very hot, and gives in the prolongation in B a narrow flame excessively brilliant, and of which the instrument only utilises a small circle of 2 millimetres in diameter. It is better to feed the flame frequently and with small fragments of fused salt, for if there is too much or too little, the intensely luminous flame B is not obtained with the same completeness. It is essential to obtain this brilliant light B, and the shape of the flame depends on the position of the spoon. In burners of high pressure and in the spirit lamp the flame does not require regulating. In the burner of low tempera- ture it is necessary to regulate by the collar v. The edge of the spoon should be placed 15 millimetres above the tube T. This is necessary, because it is often attempted to bring the spoon into the centre of the flame, to obtain more light ; if the spoon is out of order it can be drawn to the side while the gas is burning, and raised or lowered, or advanced more or less. When in its right place the brilliant interior flame B is perceived. With this arrangement there is no risk of the fused salt falling into the tube x and obstructing the gas jet. Should the spoon become coated with small spots they must be removed, as they cause irregularity in the flame, and if a whitish deposit appears the spoon is taken out and washed. The tube T is 13 millimetres in diameter. It has no collar to close the air holes, and is suited for all pressures down to 25 milli- metres. Its lowest limit is reached when it begins to burn inside the tubes. The stronger the pressure the more intense is the light and the steadier the flame. With a pressure of from 30 to 40 millimetres, for example, and two jets, the light is quite sufficient for all purposes. In order to light the burner the air holes are closed with two fingers, and the light applied from above. The column of the burner is not fixed in the socket, so that it is possible to employ two systems of burners and to bring them near enough for the chimney to touch ; four flames are thus obtained when a more intense light is required. BURNER OF LOW PRESSURE. This burner is employed when the gas pressure is under 25 millimetres of water. It is similar to the last, but the light is neither so intense nor so steady It is possible, however, to do work with it, but the spirit lamp (eolipyle) is preferable. SPIRIT LAMP (Fig. 5898). This lamp gives an intensely yellow flame and in every way takes the place of the gas lamp, especially when the pressure is I less than 25 millimetres (i in.) of water. Methylated spirit or wood spirit may be used. L. Lamp to heat boiler H, fed with spirit. A. Screw with washer into which wick is inserted. A. Screw with washer, screwed loosely on A. It serves to regulate the flame ; in working it is unscrewed by two or three turns. N. Strong frame containing lamp L and supporting boiler H. H. Boiler of copper, containing the spirit. It is hard soldered to the support N. TT. Forked tube-screwed on to I and carrying the two chimneys cc. cc. Chimneys bearing two platinum spoons GO, and terminated at their lower end by two small tubes soft soldered into tube TT. They can be put aside in the case, for example, of adapting two spirit lamps. GO. Spoons fixed by means of pegs or pins at the corners ; they are easily replaced. v. Collar for opening or shutting the air holes. VALVE. E. Screw with washer, bearing the valve s and screwed into the cone F. p. Ring of lead forming joint. s. Valve, j. Stem of valve. R. Spring to close the valve s. TO PREPARE THE LAMP FOR USE. Unscrew A and withdraw the wick, introduce a small funnel with the wick inside, and pour spirit slowly until the lamp is nearly full. Replace the saturated wick in A, and rescrew it on the lamp. Unscrew D 2 or 3 millimetres, and pass the wick through lit about 4 millimetres. There is a small hole in the upper part of the lamp for the admission of the air required to replace the spirit as it is consumed, |and it is necessary to see that it is not stopped up. 'In CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. BOILER. Loosen the screw E which carries the valve s, in order to make sure that the latter is working well, and that the spring is The rod j should be centred in its hole, but if it is not so exactly it is essential that it returns quickly to its place when acted on in any direction. The boiler attached to the apparatus should be filled to within 5 millimetres of the edge by means of the funnel, and care taken to rescrew E firmly to avoid any leakage. The tube T is unscrewed, and to make sure that the hole in the cone placed within I is quite clear, a needle or pm is inserted 4 or 5 millimetres. Tie adjustments o/ the valve s and of the small hole i are important, and ensure the proper working of the apparatus. CHIMNEYS AND SPOONS. The chimneys cc and spoons GG are properly placed so as to give the intense inner flame B, and the two flames are arranged one behind the other in the axis of the saccharimeter. It is necessary to replace the salt more frequently in the spoon than when using the gas burner. MANIPULATION OF THE LAMP. The screw E being firm, the tube T and the chimneys in their places, the operator should close the collar and light the lamp L, and wait about three minutes. It is better to wait than to draw the wick out more than 4 millimetres. When the sound of escaping vapour is heard the two extremities TT are lit, and the air holes opened. If it is too soon the flames will burn in the tubes, and if this happens they should be extinguished for a while. If the pressure in the boiler H is sufficient the flame will burn at TT with a small violet interior cone D (Fig. i). At first the cone is rather low and unsteady, but it soon gives an intensely yellow flame. It occasionally happens that the lamp gives too little light and tends to burn inside the tube, or too much light, and appears to rise up and quit the tubes. In either case the flame can be regulated by the screw D ; by screwing tighter it increases, and by unscrewing, it reduces the flame. Generally it is unnecessary to touch it when the wick is drawn through 4 or 5 millimetres. Finally, when the spirit in the boiler is nearly burnt the two flames assume a particular form. The interior cone disappears and the flame lengthens, the bubbling in the boiler also ceases. The lamp should then be withdrawn and extinguished. The measure cf spirit introduced into the boiler lasts about twenty-five minutes. It is as well to use a measure when filling the boiler so as to avoid pouring too much in. When alcohol is employed the collar should be raised so as to give a full supply of air, but with wood spirit it should be lowered. If anything abnormal is observed the lamp should be at once withdrawn. The base of the pedestal N is cut on one side in view of the possible employment of two lamps in order to obtain when neces- sary a still more brilliant light. They are supported in such a manner that the four chimneys touch as well as the cut side. The position of the two chimneys of the second lamp is changed in order that the four flames may be in the same prolongation and in the axis of the saccharimeter. The centre of the flame ought to be 20 centimetres from the lens B of the polariser. DESCRIPTION OF APPARATUS (Fig. 5888). The illustration represents the grand model set up ready for use, as seen from the side. A. Yellow monochromatic jets, placed 20 centimetres from B. B. Lens, screwed on the tube I. i. Bronzed tube carrying lens B and screwed on to E. E. Barrel, carrying a diaphragm with small hole, which receives a cap containing a crystal of potassium bichromate, the object of which is to act as a ray filter and to render the flame more nearly approaching monochromatic light. When the liquids are yellow (but clear) the bichromate crystal is not used. It is only inserted when the liquids are colourless. R. Tube carrying the lever K, it enters into p, and bears a tube containing the polariser, and a lens which can be unscrewed. p. Tube fixed on the body of the instrument L. D. Diaphragm, one-half of which is covered by a plate of quartz, which is in a line with the telescope OH. K. Lever fixed on polarising tube R, and rendered movable by the crank j. j. Crank fixed on the shaft x. x. Shaft carrying the crank j and the lever u. U. Lever fixed on x to turn the polariser by means of j and K, and in order to give more or less light. If the liquid is little coloured, the lever is raised as far as the stop. If it is coloured, it is lowered more or less. Body of apparatus in bronze, V-shaped, 60 centimetres long, planed and dressed, c. Disc carrying the divisions and the index. M. Mirror, throwing the light from the burners on to the divisions, and obviating the employment of an auxiliary light. N. Lens for reading the divisions of the scale. H. Eyepiece, placed in tube which carries the index. It possesses an angular movement. F. Regulating screw, to establish uniformity of shades, when the zero of the vernier coincides with that of the coriesponding division. It pushes the tube H, which a strong counter spring brings back. o. Cap of eyepiece, movable in H. MANIPULATION OF GRAND MODEL. The lever u being raised to its stop and the screw Q pressed firmly, the apparatus is directed towards the flame A. The observer looks through the lens N and adjusts its focus, the mirror throwing the required light on the divisions. On looking through the eyepiece, and turning the screw G, the appearance a or c of Fig. 5897 is seen, that is, a disc divided into two, one-half clearyellow, the other half dark yellow, and the tube o is pushed in or out to see their separation clearly. This point is very important, in order to establish later the uniformity of shades. The better it is done the more sensitive is the apparatus. There should be no perceptible line of division between the two halves of the disc. CROSS STREET • HATTOTST GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. By means of the two axes of rotation, Q and s, the instrument is directed to the position which gives the clearest disc, with the maximum of light. The screw G is rotated in order to make the zero of the vernier coincide with the zero of the scale. If it is already regulated the two halves of the field will present a grey-yellowish shadow exactly equal in intensity. If it is not quite regulated the appearance a or c will be observed. In order to bring about uniformity of shade it will be necessary to turn the screw F, which is only employed for this purpose. This is turned in the right direction when the dark side becomes clear and the clear side becomes dark. The position of uniformity of shade is reached when, in turning the screw c alternately to right or left by fine movements, the appearance of b, Fig. 5897, to that of a or c, in order to stop finally at that of b, is successively observed. When this is the case the appearance B should indicate zero on the scale. When the tube containing the sugar solution is interposed, the field must be focussed by drawing out o. The screw G is then turned until uniformity of shade is established. Irregularity of shade at the neutral point is generally noticed. It arises when the flame is intense and the liquid under observa- tion is very slightly coloured, and is due to the flame, which is not absolutely monochromatic. It is preferable in this case to interpose the cap containing the bichromate crystal, which is placed in E. If there is not the same shade, grey-yellowish, an exact point can be made by proceeding as follows : — The line of separation in the centre of the two half-discs is fixed, and the screw G turned alternately in one direction or the other until uniformity of shade is near. When the oscillations become slight there is the appearance of a slight shadow which seems to go and to come from each side of this line, and the movement is arrested when it seems stationary ; it now remains bright, and even disappears. At first no difference in colour is noticeable, but by removing the eye for a moment, and again looking, a slight difference is observed. In the sugar industry it is often necessary to test juice and coloured syrups, and these, when placed in this apparatus (the lever u being raised), or in any other saccharimeter, are frequently too dark coloured to be read. In such a case this apparatus offers a resource that is possessed by no others, it permits of the lever u being lowered gradually, so that more light may pass into the instrument. The advantage of being able to read with an approximation sufficient for ordinary work is thus possessed by the instrument. In such cases it is impossible to see anything with other saccharimeters ; it avoids, more particularly, the decolourising by animal charcoal, a long operation and liable to error by the quantity of sugar retained by the charcoal. It is advisable to determine the angle through which the lever is to be turned, since the angle obviously varies with the colora- tion of the liquid. DESCRIPTION OF SMALL MODEL. The manipulation is the same as for the grand model, except that the levers j and K, which are vertical in the grand model, are horizontal and to the right in the small one. The shaft x and the lever u do not exist, K is moved direct and J is fixed. In the old models K carried some divisions which served as guide marks, but these are now dispensed with. The lamp is placed on the table at 20 centimetres from the polariser. CLEANING THE PRISMS AND LENSES. The apparatus is so constructed as to be separated into its different parts which can be carefully cleaned and freed from dust or dirt. Polariser. — B and I unscrew, the cap with bichromate crystal can then be taken out. The tube R is drawn out, the pin of lever K is removed, freeing crank j. R being free, the interior cap containing a crystal of spar can be separated ; it also carries a lens which unscrews. D is drawn out ; it is secured by a pin. Analyser.— F unscrews, the tube H is drawn out, and the grooved tube removed, which contains a crystal of spar and a lens which can be unscrewed. When cleaning the prisms and lenses, care must be taken not to scratch them. When H has been replaced, the screw F should be secured and the zero re-established. The cap o being unscrewed, the small barrel carrying the concave eyepiece can be separated. The lens N also unscrews. TUBES. It is now generally admitted that with this saccharimeter it is possible to read to -f^ of a division. It is necessary, in order to profit by all the precision of the instrument, and to ensure the correctness of the result, that the accessories, such as the tubes, graduated flasks, weights, etc., be equally correct. Each observation tube must be exactly the length it is stated to be. The makers attach a great importance to the construction of the tubes. For several years now the tubes have been made with caps fitted with springs and bayonet joints, to replace the former very defective tubes, which had screw caps. They present the following advantages : — The length is calibrated, the ends are exactly plane parallel and at right angles to the axis of the tube. The end pieces are of untempered plate glass with parallel faces. They are fixed by means of a spring confined in bayonet caps. The tubes are accurately centred. In spite of the care in the execution, some of the readings may show a difference when the tubes are rotated in the instrument. It is, however, possible to obtain correct readings as follows : — A mark is made on the tube and it is rotated in several positions, two or three times, for example, and the mean of the readings taken. A single reading will then be sufficient. ANALYSIS OF DIABETIC URINE. Use the divisions representing percentages of sugar. Take a flask graduated to 100-110 cubic centimetres, pour into it too cubic centimetres of urine and add 10 cubic centimetres of basic acetate of lead. The uric acid as well as the colouring matter I is precipitated. Filter and fill up the 22 centimetres tube. If a tube of 20 centimetres was used, it would be necessary to add to the result a tenth more. The rotatory power of the diabetic sugar (or glucose) is to that of cane sugar as 73 is to 100 ; that is to say, 100 degrees of the saccharimeter corresponds to 22.2 grammes of diabetic sugar, dissolved in 100 cubic centimetres or I 222 grammes per litre, which makes 2.2 grammes per saccharimeter degree. In order to obtain the number of grammes of sugar contained in a litre of diabetic urine it will be necessary then to multiply the number of degrees and tenths read on the sacchari- ' meter by 2.22. Example. — Urine read 5.2 sugar degrees, then 5.2x2.22 = 11 54 grammes glucose to a litre of urine. 1077 ? BAIRD &TXTLOCK (LONDON) LTD. LAURENT'S SACCHARIMETER FOR THE ORDINARY WHITE LIGHT. The polariscopc just described is constructed for use with yellow sodium light. It is a general apparatus, and serves for all rotatory substances, and it is recommended for research laboratories, scientific establishments, etc., notwithstanding the trouble which the production of the sodium flame occasions. But for industrial purposes, as in the case of refineries where sugar is the principal substance, and where speed is a desideratum, the employment of an ordinary white light is preferable, as it is always at hand. In order to arrive at this object, there is interposed between the scale c and the analyser OH of the polariscope already described a Soleil compensator (a quartz wedge). This is shown in Fig. 3. The lens N, the screw F, and the analyser OH (placed behind the compensator) are of the same construction as in the other instrument. The scale c is replaced by a disc which acts as a screen (c in diagram). The rest of the instrument is like Fig. 3, except that in place of the gas burner any white flame may be employed which is placed 20 centimetres from the lens n. The app-arance seen in the instrument is one of light and shade, and there is no sensible colour visible, as in the old Solei. sacchanm«t«-. It is possible by means of the lever u to obtain more or less light as is required. A flat flame of gas or of petroleuir employed in the direction of its length is much more intense than a rounded jet. The manipulation of this instrument is almost the same as described for the grand model. The circular divisions of the dia c and the index, Fig. 3, are replaced by the rectilineal di\ isions of the scale R, and of the vernier v. In order to adjust the apparatus to zero the zeros of the vernier and scale are made to coincide, and if this does not produce uniformity of shade, the screw F i; 'urned one way or the other until the field is neutral. If the liquid to be measured gives a rotation above, for example, 60 degrees, it may be a little more exact to regulate the apparatus, not to zero, but to the 100, with a standard quartz plate. This is placed in the apparatus, the zero of the vernier \ brought on to the division corresponding to the exact value of the plate, and the uniformity of shades established by the screw F, When white light is used it is necessary to leave the bichromate crystal E, Fig. 3, in the apparatus. To bring the apparatus to the primitive state of the polariscope (with sodium flame), draw out the compensator (a pin deter- mines its position), replace N, F, and OH to their first position (Fig. 4), then place the zero of the vernier opposite the zero o: the dial, and establish the uniformity of shades by looking into o and by turning F. A description of this new apparatus was presented to the Academy of Sciences by N. Cornu in February, 1882, and to the Societe francaise de Physique by M. Dufet in May, 1882. 5908 5907 Apparatus for extracting the cane sugar from beet sugar for polarisation, as described in J.S.C.I., p. 753, July, 1901, and by A. Hergfeld, Zeits, Vereins Deutsch Zuckerind 1001 (543), 334-335 ' each £0 12 Extra Flasks 5908s Educational Set of Polarising Apparatus, complete in polished wood case, comprising analysing bundle, rotating Nicol prism on stand. Objects :— Benzoic acid, section of quill, gypsum even tint showing complementary colours, ditto mica, selenite' wedge and selenite design, also three uniaxial and biaxial crystals in brass cells, demonstrating the rings surrounding the optic axes. The whole packed with full instructions for use 1 1 £0 2 ( £1 10 ( 1078 SGCTIQ-N XXI. HOFFMANN'S Volumetric Apparatus 1079-1087 SecTicosr XXII. Lecture Diagrams Anatomical Models 1087-1098 1099^1105 The selection of Anatomical Models is necessarily incomplete. Upon receipt of particulars we shall be pleased to quote for customers- requirements. 14. CROSS STREET. H^TTON GARDEN EC BAIRD & IATLOCK: CONDON) LTD. v The following are the different Sections in our Catalogue. Those marked * are also printed separately. Section No. 1.* Laboratory Fittings 2.* Bacteriological Apparatus Chemical Physiology Apparatus Microscopes and Microscopical Accessories Balances and Weights Chemical Apparatus Botanical Apparatus Gas Analysis Apparatus Milk Analysis Apparatus Refractometers Oil Analysis Apparatus Water Analysis Apparatus Cement Testing Apparatus Leather Testing Apparatus Paper Testing Apparatus Physico Chemical Apparatus Pyrometers Calorimeters Seed and Soil Analysis Apparatus Spectroscopes and Polariscopes Volumetric Apparatus Anatomical Models Meteorological Apparatus Assay Apparatus Chemicals 3. 4.* 5.* 6.* 7.* 8. 9." 10. 11.* 12. 13. 14. 15. 16. 17.* 18.* 19.* 20.* 21. 22. 23. 24.* 25.* Pages Nos. 14-56 57-161 162-192 193-320 321-382 383-816 817-842 843-886 887-894 895-902 903-926 927-933 934-946 947-949 950-951 952-976 977-1006 1007-1022 1023-1042 1043-1078 1079-1087 1088-1105 1106-1124 1125-1172 1187-1246 14 CROSS STREET- HATTON C'.ARDEN E- C ^-> 1 BAIRD &TATLOCK (LONDON) LTD. SECTION No. 21. Hoffman's Apparatus for Volumetric Analysis. (See his " Introduction to Modern Chemistry," or Roscoe and Schorlemmer's " Inorganic Chemistry.") u 5909-5911 5912-5914 5918-5923 Apparatus to show that three volumes of hydrogen and one volume of nitrogen form two volumes of ammonia gas. Consists of a U tube, with two stopcocks and platinum elec- trodes, one limb of U tube graduated 50 cubic centimetres. After filling the tube with mercury, two volumes of ammonia gas are introduced into the closed limb and decomposed by sparks from an induction coil. The volume of gas gradually increases, and finally produces three volumes of hydrogen and one of nitrogen . . . . . . . . £096 Apparatus, as above, with metal stand . . . . . . . . . . ..£0186 Apparatus, as above, with wooden stand . . . . . . . . . . £0 14 0 Hoffmann's Apparatus, with one stopcock and closed limb, with platinum electrode, graduated into 50 cubic centimetres . . . . . . . . ..£086 Hoffmann's Apparatus, as above, with metal stand . . . . . . . . £0 17 6 Hoffmann's Apparatus, as above, with wooden stand . . . . . . . . £0130 Hoffmann's Apparatus, as No. 5912, but with closed limb ungraduated . . . . £060 Hoffmann's Apparatus, as above, with metal stand . . . . . . . . £0150 Hoffmann's Apparatus, as above, with wooden stand . . . . . . . . £0 10 6 Hoffmann's Apparatus for the decomposition of water. Consists of two tubes with stopcocks and platinum electrodes, and a tube with bulb reservoir, all being connected at bottom. Two or more Bunsen's or Grove's Cells are required for the decomposition. The gases are collected separately in the tubes and tested at the stopcocks . . . . £0 12 C Hoffmann's Apparatus, as above, with metal stand and double terminals . . . . £140 Hoffmann's Apparatus, as above, with wooden stand „ ,, . . £0 18 6 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. i 1079 BAIRD &TATLOCK (LONDON) LTD. 5921 Hoffmann's Apparatus for the decomposition of water, as No. 5918 with tubes each graduated into 50 cubic centimetres 5922 Hoffman's Apparatus, as above, with metal stand and double terminals 5923 Hoffman's Apparatus, as above, with wooden stand and „ „ £0 16 £186 £130 5924 5925 5926-5928 5924 Apparatus, small U shape, for decomposition of water, with platinum electrodes and graduated tubes 10 cubic centimetres 5925 Apparatus, small, for decomposition of water, with graduated tubes and platinum electrodes in basin on wooden stand 5926 Apparatus, for the decomposition of hydrochloric acid, with movable carbon electrodes. The tubes should be filled with a saturated solution of a salt containing 15 per cent, hydrochloric acid . . . . . . . . . . . . . . . . £0 12 0 5927 Hoffman's Apparatus, as above, with metal stand and double terminals . . . . £140 5928 Hoffman's Apparatus, as above, with wooden stand and „ „ . . . . £0 18 6 5929 Apparatus, for hydrochloric acid as No. 5926, graduated into cubic centimetres . . £0 15 6 5930 Apparatus, as No. 5929, with metal stand and double terminals . . . . . . £176 5931 Apparatus, as No. 5929, with wooden stand and „ „ . . . . ..£120 5932 Apparatus for the decomposition of ammonia. The same form as last, with movable carbon electrodes. The tubes should be filled with a saturated solution of a salt containing 15 per cent, of ammonia . . . . . . . . . . . . . . . . £0 12 0 5933 Apparatus, as above, with metal stand and double terminals .. .. .. .. £140 5934 Apparatus, as above, with wooden stand and „ ,, . . . . . . £0 18 6 The three apparatus (Figs. 5918, 5926, 5932) may be connected together for the simultaneous electrolysis of hydrochloric acid, water, and ammonia. N.B. — Care should be taken after the battery is connected with the electrodes to leave the stopcocks open for a few minutes before proceeding to collect the gases. 5935 Platinum Electrodes, on rubber corks, to suit Apparatus 5926 and 5932 when used for decomposition of water . . . . . . . . . . . . per pair £086 5936 Carbon Electrodes, with rubber corks and binding screws, for Apparatus Nos. 5926 and 5932 • • • • • • • • • • . . . . . . . . per pair £036 CROSS STREET- HATTOTST GARDETST E-C 1080 BAIRD &.TATLOCK. (LONDON) LTD. 5937 5938 5939-5941 5937 George's Apparatus, for determining the composition of ammonia, sulphur dioxide, water, etc. (See Chemical News, p. 303, vol. Ixxvii.) 5938 Flask with platinum electrodes, to show decomposition of steam 5939 Apparatus for the electrolysis of hydrochloric acid, water, and ammonia. Consisting of a V tube closed at one end, with two platinum electrodes. On filling the tube with the liquid to be decomposed , and connecting the electrodes with two or more Bunsen's or Grove's cells, the respective gases are evolved from the surface of the platinum, and can be collected and tested over a pneumatic trough. By reversing the poles of the battery the position of the gases is reversed, the gas which was collected in the open tube being now found in the closed limb, and vice versd. Price 5940 Apparatus, as above, with metal stand 5941 Apparatus, as above, with wooden stand £0 £0 £0 8 £0 13 £0 11 5942 5942 Apparatus for the volumetric analysis of the mixed gases from the decomposition of hydro- chloric acid consisting of — Electrolysis jar or cell, with platinum electrodes. Tube with two stopcocks. Absorption cylinder with tubulure. Absorption jar, 2iJ in. by 2§ in. Supports for tube. • Price complete on stand The electrolysis jar is filled with strong hydrochloric acid, and the mixed gases are led to tube ; excess being taken up by absorption cylinder, which is filled with pumice stone moistened with a solution of soda. The stop- cocks are closed, and on cooling one end of the tube with ether, a little strong solution of potassium iodide is introduced by suction. The potassium iodide is at once decomposed, and steel-grey iodine deposited. More of the solution is introduced, until it begins to have a brown colour. Shaking the tube carefully hastens the reaction. Finally, the tube is inserted in a weak solution of potassium iodide, and the lower stopcock opened. On adjusting the level of the liquid inside the tube with that in the jar, the residual gas (hydrogen) will be found to occupy one-half the tube. I. 2. 3- 4- 5- £166 1081 BAIRD & WLOCK (LONDON) LTD. 5943-5945 5949 5943 Apparatus for the decomposition of hydrochloric acid by sodium. 5950-5952 Price, glass only £070 Consists of a U tube with two stopcocks, and without electrodes. The tube is first filled with mercury, then pure hydrochloric acid gas is introduced into the closed limb, level of mercury adjusted and volume noted. Sodium amalgam is then poured into open limb, which is corked and the tube shaken ; this is repeated until no reaction takes place, when on adjusting the level of the mercury, the volume will be found reduced one-half, the residue being hydrogen. 5944 Apparatus, as above, with metal stand .. .. .. .. .. •• £0 16 0 5945 Apparatus, as above, with wooden stand .. .. .. .. .. •• £0 11 6 5946 Apparatus, as above, but with stopcock at bend only, one limb closed . . . . £060 5947 Apparatus, as No. 5946, with metal stand .. .. .. .. .. •• £0 15 0 5948 Apparatus, as No. 5946, with wooden stand . . . . . . . . . . £0106 5949 Apparatus for the volumetric analysis of ammonia by the aid of chlorine. Consists of a tube about 3 ft. long closed at one end, with a stopcock a few inches from the top, and of an immersion jar the same height. Price, including table support . . . . £0 17 6 The lower or larger portion of tube is filled with chlorine gas by displacement, and it is then divided into three equal portions by means of indiarubber bands. A strong solution of ammonia is introduced into the small space above the stopcock. On opening the stopcock and admitting the ammonia into the lower part of the tube it is rapidly decomposed, ammonium chloride and nitrogen being formed. On cooling the tube in a cylinder of water, and allowing a weak solution of sulphuric acid to flow into the tube by means of a syphon, one of three parts of the tube remains filled with nitrogen, the three parts of chlorine having combined with three of hydrogen to form one molecule of hydrochloric acid. 5950 Apparatus to show that oxygen, when combined with carbon or sulphur, retains its original volume, and hence, that two volumes of carbonic acid or sulphurous acid contain two volumes of oxygen. Price glass part only . . . . . . . . . . £0 12 6 5951 Apparatus, as above, with metal stand and clamp .. .. .. .. .. £116 5952 Apparatus, as above, with wooden stand ,, . . . . . . ..£0176 Consists of a U tube with stopcock at bottom and three bulbs, copper electrodes, and copper spoon introduced through the stopper into the largest bulb. The tube is first filled with mercury, and then a given volume of oxygen is introduced over mercury into the large bulb. On igniting a small quantity of carbon or sulphur in the metal spoon by means of a couple of Bunsen cells, the substance combines with the oxygen to form carbonic acid or sulphurous acid. The rapidity of combustion is controlled by letting out mercury by the stopcock. When the apparatus is cooled and the levels adjusted, the gas will be found to occupy the same space as the original oxygea. -CROSS STREET • HATTCW GARDETST, E-C 1082 BAIRD ii. TATLOCK (LONDON) LTD. 5953-5954 5957 5958 5953 Apparatus to show the contraction in volume of oxygen and hydrogen on their union to form steam. Price complete with metal stand . . . . . . . . ..£136 5954 Price complete with wood stand . . . . . . . . . . . . . . £0 17 6 Consists of U tube with stopcock and platinum electrodes at closed end. The closed limb is also encased in an outer tube or jacket, through which passes the vapour of amyl alcohol (which boils at 125° C.), the excess being condensed in glass worm attached. The U tube is first filled with mercury, and then two volumes of hydrogen and one of oxygen are introduced, and after the level of the mercury is carefully adjusted, their united volume is noted (the temperature of the gases and of the amyl alcohol vapour being the same) . The open limb is closed with a cork, and the mixed gases exploded by a spark from an induction coil, producing steam, which, after the level of the mercury has been again adjusted, will be found to fill only two-thirds of the space previously occupied by the mixed gases. 5955 Worm Condenser and Stand, for above . . . . . . . . . . ..£040 5956 Glass U Tube, with stopcock and steam jacket only, as Fig. 5953-5954 • • • • £076 5957 Apparatus to show that hydrogen and chlorine combine without alteration of volume, consisting of tube with two stopcocks and platinum electrodes . . . . . . £090 5958 Apparatus to show that hydrogen and chlorine combine without alteration of volume, consisting of tube with two stopcocks with bulb and platinum electrodes . . . . £090 5959 5959 Apparatus to show that hydrogen and chlorine always combine in equal proportions . . 5960 Apparatus, as above, on metal stand with clamp Consists of a tube stoppered at each end, and with stopcock dividing the tube into two unequal parts, one part being twice as large as the other. If hydrogen be introduced into one end of the tube, and chlorine into the other end, the stopcock opened, and the tube exposed to sunlight, hydrochloric acid will be formed, and on one end of the tube being placed in water, and the stopper withdrawn, the water will rush up, absorb the hydrochloric acid, and on the levels being adjusted inside and outside the tube, the gas (hydrogen or chlorine, whichever had been admitted in excess) will be found to occupy one-third of the tube. £079 £0 13 0 PCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK. (LONDON) LTD. 5961 5961 Apparatus to show formation of acetylene by the union of hydrogen with carbon in the electric arc. Flask with four tubulures, two fitted with carbons, with binding screws ; and the other two serve for entrance and exit of the gas All apparatus with platinum electrodes are subject to market fluctuation. £060 5962 5963 5962 Glass Apparatus for lecture experiment in the preparation of nitric oxide as devised by Prof. Senier . . . . . . • • • • • • each £076 5963 Glass Apparatus for lecture experiment to show the manufacture of sulphuric acid. Price without Bunsen burners and stands . . . . . . . . . . . . £0 17 6 The apparatus here suggested is simpler and more easily constructed than that of Roscoe and Schorlemmer, and employs burning sulphur as a source of sulphurous anhydride. Through a cork in one neck of the flask (of about a gallon capacity) is passed the neck of a small retort, contain- ing nitre and 'sulphuric acid ; through a similar cork in the opposite neck is passed one end of a piece of combustion tube, containing fragments of sulphur, and open at both ends ; through the cork at the mouth of the flask are passed two tubes, one connected with a small flask, in which water is boiled, and the other connected with an aspirator — preferably a gasholder full of water. Some of the sulphur in the combustion tube is heated to just above its melting point, when it ignites on a gentle current of air being caused to flow over the sulphur into the flask by means of the aspirator. Once started, the sulphur continues to burn by the heat of its own combustion, so long as the current of air is maintained. If it is wanted to introduce air it can be done easily without an extra tube, by stopping the aspirator a minute, when the burning sulphur is extinguished. CROSS STREET • HATTCTNr GARDETST, 1084 BAIRD &TATLOCK (LONDON) LTD. \ B Jl. r c 5964 LAJ D 5964 Hoffmann's Lecture Apparatus, after Dennis. Small pattern, made of flat tubing about 12-15 centimetres long, for use with optical lantern. The experiments can easily be thrown on the screen. Form Price B C 10/9 D 6/9 E 5/6 each. 5965 5567 5968 5965 Apparatus to show the uniform behaviour of simple and compound gases under variations of temperature and pressure Consists of U tube with stopcock at foot, one limb of which branches into two, with stopcocks, which are also surrounded with a glass tube into which water of varying temperatures can be poured. The apparatus is first filled with mercury, and then two gases are admitted into the branch tubes, and subjected to various tempera- tures and pressures, when they will be found to remain the same in volume. 5966 Apparatus, as above, metal stand 5967 Apparatus, Bunsen's, to show decomposition of water, with platinum electrodes 5968 Apparatus, Bunsen's, to show generation of hydrogen, with platinum electrodes 5969 Apparatus, Bunsen's, to show generation of explosive gas, with carbon electrodes £1 1 £0 10 0 6 £0 £0 9 6 9 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1085 BAIRI) & IATLOCK (LONDON) LTD. , 5970-5971 5972-5973 5975 5970 Apparatus to prove that it is only the external envelope of a flame that is hot, and that the centre remains cool. Without stand . . . . . . . . . . - - £030 5971 Stand with clamp . . . . . . . . . . . . . . ..£070 Consisting of a glass cylinder with wire cap at top, and with cork at lower end, through which passes a glass tube. A small quantity of gunpowder or the heads of matches is placed in the centre of the wire cap, and gas admitted by the glass tube at bottom. When the gas has expelled all the air from the tube, light from above. 5972 Apparatus to burn oxygen in hydrogen or illuminating gas. Without stand . . . . £060 Consisting of two glass lamp chimneys connected at bottom by a piece glass tubing ; into each cylinder is also led at bottom a narrow glass tube. To manipulate, close one cylinder (A) at top with a cork.and lead into it (a) hydrogen until all the air is driven out and hydrogen begins to come into the other cylinder, when apply a light to it at b', removing the second cylinder (B) for that purpose. Before replacing the second cylinder (B), lead oxygen to it (6) and regulate the flow of hydrogen by a pinchcock. In order to drive the flame from the second (B) into the first (A) cylinder, take the cork out of the first (A) and put it into the second (B) cylinder, whereby the hydrogen flame in the second cylinder (at b') becomes smaller, slips into the tube, and appears as an oxygen flame in the first (A) cylinder (at a'). This flame can also be regulated by a pinchcock. (Two cylinders, two corks, and indiarubber stopper tube with platinum point.) 5973 Stand with double clamp, two pinchcocks, and indiarubber tubing . . . . . . £0 16 6 Coal gas is introduced into the bulb by the side tube in neck, and after all air has been expelled, the gas escaping at top tubulure is lit and the air tube slipped down through cork to centre of the bulb, where it will continue to burn. 5974 Apparatus by Kekule, to light one gas in an atmosphere other than the air by means of the electric spark . . £0 12 0 For example, to burn hydrogen in oxygen or chlorine ; chlorine gas in hydrogen ; illuminating gas or ammonia in oxygen. Consists of a flask, capacity about i litre, with two tubes and neck, all fitted with indiarubber corks. Through the neck, which is placed mouth downwards, two tubes are passed, one short, the other long, and reaching to about a third of the diameter of the flask. By one tubulure the two platinum wires are led to near the top of the long tube, which enters from the bottom. Through the other tubulure a short glass tube is inserted. If it is desired to burn oxygen in illuminating gas, the gas is led into the flask by the tubulure at side, and when all the air is expelled, oxygen admitted by the long tube through the neck is lit by the electric spark at the burner, the wires being at once drawn back to avoid injury. The gas which is to form the atmosphere is led into the flask by the tubulure at the side when it is heavier, and by the neck when it is lighter than the air. (Flask, three indiarubber corks, tubes, and 5974 platinum wires.) 5975 Lecture Apparatus, for showing combustion of air in an atmosphere of coal gas, etc., by Mr. George Craig (see Chemical News, 3rd August, 1888) . . . . . . £040 1086 BAIRD &TATLOCK (LONDON) LTD. 5976 5978 5976 Apparatus to burn air in illuminating gas, and to show the principle of Bunsen's burner . . £036 5977 Stand with clamp, for above . . . . . . . . . . . . extra £070 Inside the cylinder the oxygen of the air burns in the illuminating gas, at the cover (c) the illuminating gas in the oxygen of the air. 5978 Apparatus for burning one gas in another. Price without stand . . . . . . £0 10 6 The gas to be burned is admitted by the glass tube, and burns at the platinum jet, the air or gas in which it is burnt enters by the side tube, and the stopcock at top may be used to regulate the combustion. 59791 Diagram showing classification of the elements, 44 X 68 in., mounted on cloth, varnished, with rollers . . . . . . . . . . . . . . . . ..£150 CLASSIFICATION OF THE ELEMENTS. The Classification of the Elements is arranged according to the Periodic System, but the Zero Group has been omitted to save space, and thus the Elements Helium, Neon, Argon, Krypton, and Xenon, are placed in Group VIII. in the order of their atomic weights. The sub groups are differentiated by the colours red and black, and the unclassified Elements are placed together in the sequence of their atomic weights. DIAGRAM SHOWING CLASSIFICATION OF THE ELEMENTS. INTERNATIONAL "A" •^UiiU'J'ilf^t.mili^Sil.'Ii IsuQ^~ OXYGEN — I6-OO HYDROGEN — 1-OO8 fOMIC WEIGHTS GROUP I GROUP D CROUP IH GROUP IV GROUP V GROUP VI GROUP VII GROUP VBI Hydrogen H- 1-008 Helium He-40 Lithium Li - 7-00 Glucinum GI-9-1 Boron B-ll 0 Carbon C-12-00 Nitrogen N - 14 • 01 Oxygen 0-16-00 Fluorine F-19-0 Neon Ne-200 Sodium Na- 23-00 Magnesium Mg- 24-32 Aluminium AI-27-1 Silicon Si -28 3 Phosphorus P-3I-D Sulphur S- 32 07 Chlorine CI-35-46 Argon A- 39 9 Potassium K-39-10 Calcium Ca-40-09 Scandium Sc-44 1 Titanium Ti-48 1 Vanadium V-51 2 Chromium Cr-52 0 Manganese Mn- 54-93 Iron Nickel Cobalt ft- 55 85 Nl - 58 68 Co- 58 97 Copper Cu-63-57 Zinc Zn- 65-37 Gallium Ga-69-9 Germanium Ge-72 5 Arsenic As- 74 -96 Selenium Se-79-2 Bromine Br-79 92 Krypton Kr-83-0 Rubidium Rb-85-45 Strontium Sr-87-62 Yttrium Y-89 0 Zirconium Zr-90-6 Columbium Cb-93 5 Molybdenum Mo- 96 0 Ruthenium Ru - 101-7 Rhodium Rh - 102 9 Palladium Pd - IDS 7 Silver Ag- 107-88 Cadmium Cd-112-40 Indium ln-114-8 Tin Sn 119 0 Antimony Sb-l20-2Q Tellurium Te=l27-5 Iodine 1-126-92 Xenon Xe-1307 Caesium Cs-132-81 Barium Ba- 137-37 Lanthanum La -139 0 Cerium Praseodymium Neodymium Samarium Europium Gadolinium Ce-14025 Pr-1406 Nd-144-3 Sa-150-4 EU-1520 Gd-157-3 Terbium Dysprosium Erbium Thulium Ytterbium Lutecium Tb- 159-2 Qy=l625 Er- 167-4 Tm- 168-5 Yb- 172-0 LU- 174-0 Tantalum Ta- 181-0 Tungsten W 184-0 Osmium Os- 190 9 indium Ir - 193 1 Platinum Pt - 195 0 Gold Au-197-20 Mercury Hg- 200-0 Thallium TI-204-0 Lead Pb-207-IO Bismuth Bi-208 0 Radium Ra- 226-4 Thorium Th-23242 Uranium U = 238 5 Published by BAIRD & TATLOCK.(LONDON) LTD London. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIKD ^rarLOCK (LONDON) LTD. SECTION No. 22. Lecture Diagrams and Hygiene Models. IRON & STEEL DETERMINATION OF MOLECULAR WEIGHT. MSTKt* «•-* KWULtl Hll 5980-5982 5980-5982 5980T Low's Chemical Lecture Charts. A series of twenty-five sheets, 40 by 30 in. Price plain 5981T Low's Chemical Lecture Charts. Price backed with linen . . . . . . 59821 Low's Chemical Lecture Charts. Price backed with linen, varnished, and mounted on rollers .. .. .'. .. .. .. .. .. The object of the charts is to simplify the work of the teacher by supplying him with first-rate drawings in bold outline, of arrangements of apparatus for elucidating the more difficult experimental details of chemical manipulation. Apparatus, inaccessible to ninety-nine per cent, of the schools of the country on the ground of cost, is always available in the lecture halls of the leading colleges and universities. A cheap equivalent to the less pretentious classes has long been desired, and we therefore appeal to all teachers of chemistry who are preparing pupUs for the examinations of the Science and Art Department, the London Matriculation or Intermediate Science, Oxford and Cambridge Local, Preliminary Scientific, etc., etc., to carefully consider the merits of these aids to the teaching of chemistry. They have been compiled from the most reliable sources, and embody much pictorial information which is not easy of access to most teachers, many of the illustrations not yet having appeared in ordinary text-books. They would be of great service in all organised science schools, and an acquisition to every chemical laboratory, serving not merely as aids in the lecture, but also as a means of mutual help among students. Fig. I. » 2. ,. 3- Fig. i. „ 2. LIST OF SUBJECTS No. 1. Catalan Forge for Iron-smelting. A modern Blast Furnace. The Bessemer Process. £1 11 £2 10 £3 10 0 v 0 Fig. i. » 2. ., 3- No. 2. Manufacture of Nitric Acid. Boric Acid. No. 3. Gravimetric Composition of Air (Dumas & Boussin- gault). Atomic Weight of Carbon. Gravimetric Synthesis of Water. No. 4. Lothar Meyer's Curve. No. 5. Isolation of Fluorine (Moissan's Apparatus). U tube, sectional view. Preparation of Anhydrous Hydrofluoric Acid FIGURED ON LOW'S CHARTS. No. 6. Determination of Molecular Weight. Fig. i. Victor Meyer's Apparatus. „ 2. Dumas Method. ,, 3. Hoffmann's Apparatus. „ 4. Raoult's Method, as modified by Beckmann. No. 7. Solubility Curves. Carbonic Acid Isothennals. No. 8. Reverberatory Furnace. Pattinson's Process for desilverising Lead. No. 9. Fig. i. Distillation of Water. „ 2. Charcoal Burning. „ 3. Distillation of Coal. No. 10. Extraction and Sublimation of Sulphur Lime Burning. CROSS STREET • HATTOTST GARDETST, 1088 BAIRD &TATLOCK (LONDON) LTD. No. 11. Extraction of Zinc. Distillation of Mercury. No. 12. Fig. i. Liquefaction of Gases (Pictet's Method). . Cailletet's Apparatus. No. 13. Extraction of Phosphorus. Distillation of Iodine. No. 14. Fig. i. Bunsen's Absorptiometer. 2. Atmolysis. 3. Dissociation. 4. Sprengel Pump. No. 15. Fig. I. Oxyhydrogen Furnace (Deville & Debray). 2. Muffle Furnace (Royal School of Mines). 3. Cupellation of Silver (German Method). No. 16. Extraction of Bismuth. Preparation of Chromium (Fremy's Apparatus) . No. 17. 1. Spectroscope with Comparison Prism. 2. Reversal of the Sodium Lines. No. 18. The Leblanc Process. No. 19. Fig. I. Ammonia-Soda Process. No. 20. Fig. i. Reverberatory Electric Furnace (Moissan's). „ 2. Electrolytic Preparation of Aluminium. Heat of Combination. — Favre & Silbermann's Calorimeters. No. 21. Fig. i. Hoffmann's Apparatus for ascertaining the Composition of SO, and CO,. 2. Ozonising Apparatus. 3. Hoffmann's Apparatus for Composition of NH,. 4. Hoffmann's Apparatus for Composition of HC1. 5. Andrews & Tait's Apparatus for Composition of Ozone. 6. Composition of N,O, NjO,, etc. 7. Smithell's Apparatus for separating Flame into Inner and Outer Cones. No. 22. Low Temperature Experiments. Volumetric Composition of Water. No. 23. Figs, i & 2. Extraction of Copper, etc. Fig. 3. Furnace for refining Copper. No. 24. Manufacture of Sulphuric Acid. No. 25. Concentration of Sulphuric Acid. 5983s W. & A. K. Johnston's Illustrations of Chemistry. By Thomas J. Menzies, M.A., B.Sc. Size 50 by 42 in., coloured, varnished, and mounted on cloth and roller No. XXXV., Sheet No. i. — Elementary Bodies with their symbols, atomic weight, and quantivalence. No. XXXVI., Sheet No. 2.— Chemical physics. No. XXXVII., Sheet No. 3. — The chemistry of air and water combustion. No. XXXVIII., Sheet No. 4. — Laboratory apparatus and manipulation. No. XXXIX., Sheet No. 5.— Crystallisation. £0 12 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. vixst^ BAIRD &.TATLOCK (LONDON) LTD. THE M.C.C. CHART OF THE ECEMENT* 5985 (Dimensions 34 in. high x 40 in. broad.) The Chart of the Elements. (All Rights Reserved.) INTRODUCTION. This booklet comprises — Part I. : The Chart : its Principle and Application. Part II. : The Periodic Law and its Relation to Speculative Thought. NOTE. — With each chart Part I. is supplied free. Separate copies and Part II. can be had as follows I—- Parts I. & II., gd. each, post free. Parts I. & II. combined 1/6. The Chart of the Elements is a unique descriptive bird's-eye view or map of every metal and non-metal which is known to exist, either combined or free, in Nature, showing all the most important properties which each possesses. Each metal or non-metal occupies a separate section, and these sections are arranged upon a new plan, based upon the " Periodic Law " of the Russian chemist, Mendeleef. Thus, not only are the properties actually given available to the reader, but some idea may also be gleaned of the probable nature of the properties not yet known. The whole Chart forms, therefore, a classification of the metals and non-metals which must prove useful to all classes of workers — from the pure scientist to the business man, and to everyone engaged in experiment or research of any kind, whether he be chemist, metallurgist, engineer, electrician, physicist, naturalist, manu- facturer, or student of elementary chemistry. 5985T Roll Form to Hang on Wall. Mounted on linen, and varnished, with wooden roller . . £0 12 6 59861 Map Form. Folded to 9 by 6 in. Mounted on linen, with cloth binding . . . . £086 59871 Map Form. Folded to 9 by 6 in. with plain paper binding . . . . . . . . £036 CROSS STREET • HATTCTNT GARDETST, E- C 1090 BAIRD &T&TLOCK (LONDON) LTD. 5988-5989 The Periodic Collecting Cabinet. (Patented.) Pb" WETAL) 207-10 IV.-ll. LEAD S.G SH M.P.-.VTC. BP E. C.Equi Oxide low r . SOt, mid latter are tion*. In :in tion). lunib- tenacit It may' Wire, ftnci but TIOW Nitric Ji but it is u not cor niosp clectr to ra] place It al 5990 SPECIFICATION. Height, 40 in. ; width, 46 in. ; thickness, sj in. Two glass doors in mahogany-stained polished wooden frames, on brass hinges, with lock and key, and two flush bolts. Interior fitted with central partition and twelve movable shelves. On the background is the " CHART OF THE ELEMENTS " mounted on mill-board and varnished, and so fixed that, in the event of a subsequent edition being published, the old Chart may in a few minutes be replaced by a new. Cabinets, with glass fronts and shelves, in which the Chart is made to form the background, have been introduced to enable the student or experimentalist to extend the system, and to collect Specimens of the Elements. The system of the Cabinet enables every Element to be filed away in its proper section, where it is always at hand for examination or for the determination of its unknown properties. The educational value of the Cabinet will be at once apparent. Since many of the Elements are very rare, and some have never yet been reduced, the filling of the Cabinet with specimens must necessarily be a work of patience on the part of the collector. 5988T Cabinet and Chart (without Specimens) . . 5989r Cabinet, Chart and Fifty Specimens as per List on page 1092 5990 r Specimens of the Elements. These specimens are supplied in glass-stoppered bottles, especially suited to the cabinet. Where possible, several forms are placed together in one bottle. Prices on page 1092. £330 £880 1091 FS*E~ &. TATLOCK (LONDON) LTD. SPECIMENS OF THE ELEMENTS IN BOTTLES, as Fig. 5990, page 1091. Elements. Aluminium Antimony Arsenic Bismuth Forms in each Specimen. Foil, Wire, Powder, Grains Lump, Powder . . Crystallized Lump, Powder, Stick Price, each. £0 0 £0 1 £0 0 £0 1 8 0 8 6 Elements. Barium Boron Cerium Didymium , . Price, 5 to 20 Forms in each Specimen. grain.s, each. From Amalgam . . £0 3 4 Refined, Amorphous ..£016 Fused Electrolytic . . £0 3 10 Powder .. . . £0 8 10 c*e\ n f\ Cadmium Sheet, Wire, Powder £0 1 0 Erbium x>u / u *n 1 Gold Leaf, Foil £0 2 6 Calcium Filings s/U J. Chromium Reduced by Aluminium, Indium . . £0 8 Powder £0 1 0 Lanthanum Powder, Electrolytic . . £0 9 8 Cobalt Cubes, Powder, Sheet £0 1 6 Lithium Refined £0 2 4 Copper Foil, " Bronze - Powder " Osmium • • • • • • £0 3 10 Turnings £0 0 8 Palladium Foil £0 3 10 Iron Sheet, Wire, Reduced Powder £0 0 8 Platinum Foil £0 3 6 Lead Foil (polished and rough), Rubidium Refined £0 7 0 Grain, Wire £0 0 8 Rutherium Powder £0 8 10 Magnesium Ribbon, Wire, Powder, Turnings £0 1 0 Selenium Amorphous £0 1 0 Manganese Mercury Molybdenum Powder, Reduced by Alu- minium Reduced by Aluminium, Powder £0 £0 £0 1 1 1 0 6 6 Silicon Strontium Tantalum Tellurium Thallium Specially Refined, Cryst. From Amalgam Coml. Powder £0 £0 £0 £0 £0 Nickel Wire, Powder, Foil £0 1 0 Thorium Refined £0 1 4 Phosphorus Ordinary and Amorphous £0 1 0 Titanium Refined £0 1 ( Potassium .. £0 1 6 Uranium Coml. £0 1 t Silver Wire, Foil, Powder £0 1 6 /* Vanadium Coml. £0 1 A Sodium £0 1 0 Zirconium • . £0 1 ; Tin Powder, Wire, Foil, Grain £0 1 0 Tungsten Powder £0 1 6 Zinc Granulated, Dust, Stick, Foil £0 1 0 [ Electric Arc-light Carbon, ) Carbon •j Plumbago, and Diamond \ £0 6 6 I (Bort) I Sulphur Pure Crystallized £0 0 8 59911 Complete Set of the above 50 Specimens in bottles . . £5 5 0 lirf 14 • CROSS STREET • "HATTOTST 7,—=Jii^^^i&&&^sS£y^^m GARDEN, E- C- 1 1092 BAIRD &TATLOCK. (LONDON) LTD. 5992s Diagrams, to illustrate hygiene, suitable for class work. Size 40 by 30, on cloth, coloured. Nos. i to 20 4/- each, 21 to 24, on Cartridge 30 by 22, 2/-. 1. Source and Circulation — Physical and Chemical Properties and Natural Phenomena. 2. Pollution by Air, Soil, Animals, Storage, Shallow Wells and Distribution. 3. Purification — Separation, Distillation, Softening, and Filtration, showing New River Company's Filter-bed. 4. Soils and Water — Water-bearing Strata and Means of Access, showing Section of London Basin. 5. Fittings for Storage, Supply, and Flushing. 6. Radiation, Conduction, and Convection — Stoves and Grates. 7. Ventilation — Natural, Artificial, and System at House of Commons. 12. Drainage — Good and Bad Systems contrasted. 13. Model Sanitation — Copy of Model at the Parkes Museum. 14. Drainage Systems for Detached, Semi-detached, and Attached Houses. 15. Traps — Defective and Approved. I5a. Sewage Disposal Systems— including Bac- teriological Methods. 16. Conservancy Systems — Pails, Privies, Middens, and Destructors. 17. Disinfection by Steam, Chemicals, and Fumi- gants. 18. Bacteriology — Elementary and Diagrammatic. 19. Meteorology — Cyclones, Anti-cyclones, Rainfall, etc. 20. Clothing of Head, Feet, Body, and Furnishing. 21. Proximate Principles of Food. 22. Dietaries. 23. Constituents. 24. Elements and Compounds of the Human Body. £400 8. Air — Chemical, Physical, Physiological, and Statistical. 9. Interception and Inspection of Drains, Waste Pipes, etc. 10. Water Closets — -New and Approved. 11. Water Closets — Old and Condemned. 5993T Complete Set in Case with Diagrammette Book 5994s Additional Diagrams, on Cartridge 30 by 22 in. 25. Set of Four Diagrams illustrating London County Council Requirements the set £080 26. Grease Trap, with Flushing Tank . . . . . . . . . . ..£026 28. Drain Pipes — Patent Joints . . . . . . . . . . .,£026 29. A large Diagram of Parkes Museum Model, 40 by 30 . . . . . . £026 30. Ditto Water Pollution, 40 by 30 .. . . . . . . . . . . £026 5995s Hygiene Demonstration Models. No. i. House Sanitation. — The first copy of this model was made for the Sanitary Institute, Parkes Museum, and since its introduction has been made and supplied to nearly all technical education centres both in England and abroad. It can be used to demonstrate siphonage of traps in valve and wash-down closets, the effect of ventilation and no ventilation, compression of air, momentum of flush, protection of traps by anti-siphonage pipes, the effect produced by flushing from a siphon flushing cistern, and the proper position for connecting anti-siphonage pipe to soil pipe . . . . . . . . . . . . . . . . ..£330 No. 2. House Sanitation. — Similar to No. i, but with the ventilation shaft carried higher than the top closet and the soil pipe terminal being provided with a mica flap inlet . . £3 10 0 No. 3. House Drainage and Sewer. — This large model includes the two models Nos. I and 2, as described, and in addition gives a length of sewer about 8 ft. long by ii in. diameter, with three manholes. It also is provided with a reservoir at both ends, from the upper of which the water can be made to represent the effect of a storm of rain or sudden influx of water, and the subsequent subsidence and partial vacuum £770 No. 4. House Drainage. — This model is built up in a very practical way, with J scale pipes, traps, bends, junctions and channel, with a model inspection chamber, air- tight cover and fresh-air inlet ; concrete under the drain, and the soil is filled in up to ground level. The whole showing a well-constructed drain in section . . . . £3100 No. 5. Expansion of Air. — A model for demonstrating the effect of expansion and contraction of air on the water seal of traps . . . . . . . . . . £0126 No. 6. Permeability of Soils. — A model to show the ready passage of air through soils £1 10 0 1093 BAIRD &TATLOCK (LONDON) LTD. No 7 Siphonage Model.— Consisting of one W.C. fitted to soil pipe (in glass) with siphon flushing cistern, fitted to wooden stand. The action of valve or wash-down closets and all phases of siphonage and anti-siphonage can be demonstrated. In box No. ii. Water Pollution.— A most interesting model, devised to show how water in high pressure service pipes (when running full bore) takes in sub-soil water and air. This will be found a most valuable addition for Teachers of Public Health No. 12. Ventilation. — A model designed to show how air is vitiated by combustion by the evolution of CO3 and several interesting facts about ventilation. This model shows the valuelessness of excess of height in a building, and the necessity of inlets and outlets for proper ventilation. Full particulars sent for demonstrating these points No. 13. Hinckes Bird's Window.— A double-sashed window, 2 ft. 6 in. by i ft. 6 in., to illustrate the simple method of fresh-air inlet without draught, as suggested by Dr. Hinckes Bird No. 15. Air Inlet (Ellison's). — This model illustrates in a simple way the effect produced by Ellison's air brick on a current of air, transforming it from a keen draught into a diffused and comfortable flow. It consists of an air brick, bellows, and indicator. Fitted on a neat wooden stand No. 16. Louvre and hit and miss Ventilators (Cooper's). — Working models in frames fitted on mahogany stands . . . . . . . . each No. 17. Dampness and its Prevention. — This model gives a practical illustration of the effect of damp and the best method of preventing the same. It consists of three piers- of brickwork, one built without, and the others with damp-proof courses, and a zinc tray. When the brickwork is placed in the tray and water is supplied to the base, the one pier becomes discoloured and illustrates how water rises in walls by capillarity, the others remain perfectly dry above the damp-proof courses. This is a most valuable model for permanent exhibition No. 18. Capillarity. — Glass model for illustrating the law referred to in above description No. 19. Siphonage. — Two glass models illustrating the action of a simple bent siphon and an annular siphon . . . . . . . . . . . . each No. 20. Force Pump. — Glass working model showing the action of raising water from a well and forcing it upwards into a cistern. Price 4/-, or on stand with well No. 21. Ordinary Lift Pump. — Glass working model. Price 3/6, or on stand with well No. 22. Water Absorption. — This model demonstrates the amount of water absorbed by an ordinary brick No. 23. Hardness of Water Test.— Set of simple apparatus for determining the degrees of hardness in any water, easily manipulated. With full description No. 24. Clothing. — Apparatus to demonstrate the heat retaining properties of clothing materials. Specimens of cotton, silk, wool, and cellular cotton are included for comparisons No. 25. Air Permeability. — Apparatus to demonstrate the ease with which air passes through an ordinary brick. The passing of the air is made visible by the introduction of a water trap £1 12 6 £220 £0 10 0 £220 £1 15 0 £1 10 0 £3 15 0 £036 £020 £086 £076 £2 10 0 £0 15 0 £1 10 0 £150 CROSS STREET • HATTOTST GARDEN, E-C 1094 BAIRD &TATLOCK (LONDON) LTD. No. 26. Water Hammer. — A glass tube containing water in a vacuum, illustrating the cause of some of the noises in water pipes . . . . . . . . ..£040 No. 27. Radiation. — Small glass model with vane delicately poised in vacuum, which will readily revolve when exposed to sunshine or artificial light . . ..£0100 No. 28. Water Tests. — For class demonstration or cursory examination, and most useful for Teachers and Sanitary Inspectors, giving reliable information of serious contamination. Complete, with instructions for use, which can be carried out without chemical experience . . . . . . . . . . . . ..£150 No. 29. Radiation, Conduction, and Convection. — An exceedingly effective and useful working model. Illustrating the three laws of heating by hot water, hot air, conduc- tion of metals and direct radiation. Can be fixed against a wall like a picture frame. Size 2 ft. by 2 ft. 6 in. . . . . . . . . . . . . . . £4 4 0 No. 30. Septic Tank. — A complete model of the sewage liquefying tank, with movable top to show interior. Made to scale about 15 in. long .. *.. .. .. £1 10 0 No. 31. Barker's Mill. — Working model to illustrate one of the most popular methods of sewage distribution, known as a " Sprinkler " . . . . . . £1 15 0 No. 32. Water Ram. — A small working model in glass . . . . . . . . £086 No. 33. Lactobutyrometer. — Marchand's process. A thoroughly reliable Milk Test for determining the percentage of Butter Fat in milk. No chemical knowledge required ; accurate results in a few minutes. Complete, with instructions and chemicals for about thirty tests . . . . . . . . . . £0 17 6 No. 34. Barometer Scale and Vernier. — Suitable for class work . . ..£050 No. 35. Water Filter. — Section of large sand filter (J scale) typical . . ..£330 No. 36. Water Filter. — (Pasteur Chamberland), in nickel case . . ..£150 No. 37. Sherringham Valve. — Fitted on wooden stand . . . . ..£076 No. 38. Tobin's Tube.— Fitted on wooden stand . . £076 No. 39. Mica Flap Valve. — Fitted on wooden stand . . . . . . £076 No. 40. M'Kinnel's Cowl . . . . . . . . . . ..£076 No. 41. Water Pipes. — Set, including Tin-lined Iron, Tin-lined Lead, Glass-lined Iron. Iron, with Angus Smith's Solution . . . . . . . . . . ..£076 No. 42. Sanitation Models. — Suitable for Hygiene Classes, including Hopper W.C., Wash-down W.C., Bath, Sink, Gulley, Interceptor, Junction, Pipes (2 sizes), Taper Pipe, Bend, P. & S. Traps, Straight Channel, Channel Bend, Model Bricks (3), Damp- ' proof Course, Ellison's Air Brick . . . . . . . . . . ..£220 No. 43. Board of Education Set. — Comprising Ellison's Air Brick, Sherringham Valve, Tobin's Tube, Mica Flap Valve, Sediment Trap, Intercepting Trap, Junction Pipe, Drain Pipes, Channel Bend, Gully Trap, Sink, Wash-down Closet, Bath, Long Hopper Pan, Damp-proof Course Water Pipes, Tin-lined Lead, Tin-lined Iron, Glass-lined Iron, and Smith's Solution coated Iron, DipstoneTrap (model), and Model Barometer Scale with Vernier. Complete Set, including Box . . . . . . . . £440 5996s " Diagrammettes." Single sheets from " Diagrammette " Book giving a separate diagram with descriptive matter, suitable for distribution to students at classes or to .large audiences. This is a most satisfactory method of teaching . . per hundred £040 1 8 .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1095 BAIRD &TATLOCK (LONDON) LTD. JOHKSTONS IUUST»»TIOItl M ll»TU«Al WIlOSOrHY 5997 5997T Lecture Diagrams. Human Anatomy and Physiology. By Sir Wm. Turner, Principal, University of Edinburgh. Varnished Sheet i.— 27 Diagrams, and Handbook, giving The Bones. The Ligaments. Sheet 2. — 42 Diagrams, and Handbook, giving Veins and Organs of Respiration. Lymphatics and Organs of Digestion. each £0 12 The Muscles. The Heart and Arteries. The Brain and Nerves. The Senses. 6000' 6001T Davies' Physiological Diagrams. For use in schools. The Diagrams are very boldly drawn for class teaching, and printed in black. Size, 30 by 23 inches. Price of the set of nine sheets eyeleted and in wrapper, and key . . . . . . . . net per set, „ Ball and Socket Joint — the Ditto, mounted on cloth Sheet i.— The Skeleton. 2. — Muscles and Bones of the Arm. 3. — Muscles and Bones of the Leg. 4. — Vertical Section of a Hinge Joint — the Elbow. Hip. 5. — Bones of the Head. 6. — Front View of the Organs of the Trunk. 7. — Posterior Surface of Trachea and Lungs. Sectional View of the Heart. 8.— The Eye. 9.— The Ear. 6002T Royal Portfolio of Pictures and Diagrams. Size, 34 by 30^ inches. Physiology 6003T Ditto. Set of 10 Sheets on one roller Sheet I.— The Skeleton. „ 2. — The Muscles. „ 3.— The Teeth. „ 4. — Organs of Digestion. „ 5. — The Circulation of the Blood For teaching of each sheet Sheet 6. — The Organs of Respiration. „ 7. — The Kidneys ; Skin. „ 8. — The Nervous System. „ 9.— The Eye. , 10. — The Ear. £0 5 £0 12 £0 £1 1096 BAIRD &.TATLOCK (LONDON) LTD. Royal Science Diagrams. Mounted in Sets. 6004T Sheets Nos. i to 7, mounted on one roller, to turn over . . . . . . per set 6005T Sheets Nos. 8 to ii, 6006T Sheets Nos. 12 to 14, ,, „ „ „ .. , 6007T Sheets Nos. 15 to 18, ,, ,, „ „ . . . . 60081 The whole Set, i to 18, „ „ „ „ . . . . The Royal Science Diagrams form an unusually complete series of illustrations for a course of elementary lessons in Physics. They illustrate, by means of sectional and other drawings, many points which cannot be so clearly shown by the use of the actual apparatus, and thus form an indispensable addition to the physical laboratory. Sheet i. — Pressure of Liquids. — With coloured pictures, showing bladder on glass cylinder experiment ; Barker's mill ; hose ; and hydrostatic bellows. Sheet 2. — Thermometer. — With coloured pictures of Centigrade thermometer ; method of finding freezing-point ; method of finding boiling-point ; and comparison of Fahrenheit, Centigrade, and Reamur scales. Sheet 3. — Air-Pump. — With coloured pictures of air-pump and receiver with valves ; and syringe with valves. Sheet 4. — Barometer. — With coloured pictures, showing the Torricelli experiment ; wheel barometer ; and Fortin's barometer. Sheet 5. — Common Pump. — With coloured pictures, showing the suction valve shut and the suction valve open ; and bellows valve and butterfly valve. Sheet 6. — Force Pump. — With coloured pictures, showing the suction valve open and the suction valve shut ; also spring valve. Sheet 7. — Pendulums. — With coloured pictures, showing the simple pendulum, the compound pendulum, the mercury pendulum, and the gridiron pendulum. Sheet 8. — First Order of Levers. — With coloured pictures of weight and fulcrum, balance steelyard, bellcrank, and scissors. Sheet 9. — Second Order of Levers. — With coloured pictures of steelyard, nutcrackers, chipping-knife, and wheelbarrow. Sheet 10. — Third Order of Levers. — With coloured pictures of steelyard, safety-valve for steam boilers, and clipping shears. Sheet 11. — Balance. — With coloured pictures of the principle of the balance, the common balance, and the chemical balance. Sheet 12. — -Wheel and Axle. — Showing coloured pictures of wheel, wheel with axle, Chinese windlass, and capstan. Sheet 13. — Toothed Wheels.— With coloured pictures, showing toothed wheels with connecting wheel, and rack and pinion. Sheet 14. — Toothed Wheels. — With coloured pictures, showing bevelled wheels, spur wheels, and crown wheel and lantern. Sheet 15. — Systems of Pulleys. Sheet 16. — Crane. — Hoisting weight. Sheet 17. — Wedge and Screw. — With coloured pictures, showing wedge, Filter's vice, double thread screw, and single thread screw. Sheet 18. — Bramah or Hydraulic Press. — With coloured pictures, showing plunger, valves, ram, and Bramah collar. Each Sheet sold separately, with four eyelets on cloth, price 2/6 each ; or mounted on cloth with rollers, 6/- each £0 14 £0 9 £0 7 £0 9 0 0 6 0 £1 12 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIR.D ScTATLOCK (LONDON) LTD. Royal Portfolio of Pictures and Diagrams. For Nature Knowledge and Lessons on Plant Life. Adopted by the L.C.C. Size, 34 by 30^ inches. 6009T First Series Sheet i. — How Plants Grow. Sheet 4. — Running and Climbing Stems. „ 2. — Roots and Tubers. „ 5. — Leaf-buds and Flower-buds. „ 3. — Structure of Stems. „ 6. — Forms of Inflorescence. Sheet 7. — Forms of Fruit. 6010' Second Series Sheet i. — Parts of a Flower. Sheet 4. — Dispersion of Seeds. „ 2. — Irregular Flowers. „ 5. — Simple Leaves. „ 3. — Fertilization. „ 6. — Compound Leaves. Sheet 7.— Leaf Details. 601 1T Third Series .. Sheet i. — Carnivorous Plants. Sheet 4. — Lichens. „ 2.— Ferns. „ 5.— Fungi. „ 3.— Mosses. „ 6. — Algae, or Water Weeds. Sheet 7. — Parasites. 6012T Fourth Series Sheet i. — Wheat, Oats, and Barley. „ 2. — Cocoa and Chocolate. ,, 3. — Grapes, Raisins, and Currants. „ 4. — Spices — Clove, Allspice, Nutmeg. 6013T Fifth Series Sheet i. — Maize, Rice. „ 2. — Lentils, Peas, Beans. „ 3.— Tea. , 4.— Sugar. Sheet 5. — Cocoa-nut Palm. „ 6. — Flax. ,, 7. — Bamboo. ,, 8. — India-rubber, or Caoutchouc. Sheet 5. — Date, Banana. ,, 6. — Tobacco, Indigo, Opium. ,, 7. — Hemp, Jute. „ 8. — Osiers, Canes, Basket-work. £0 15 0 £0 17 6 £0 17 6 £0 15 0 £0 15 6014 6014' Model of Eye, dissectable, 5 times natural size 6015* Model of Eye, dissectable, 10 times natural size e emmetropia, hypermetropia, myopia, and the use of glasses errors of refraction, in case with lenses . . £110 1093 BAIRD &. TATLOCK (LOM)ON) LTD. A6016 B6016 A6016T Optical Model of Eye, showing the image on the retina, and illustrating the effect of spectacles . . . . . . . . . . . . . . . . . . £110 B6016T Ophthalmatrope, Knapp's, to demonstrate the movements of the eye and the working of the muscles ... ..# .". .. £2 10 0 6019 6017r Brain of Man, natural size, vertically cut, divisible, with medulla oblongata, spinal cord and the nerve-roots . . . . . . . . . . . . . . ..£0110 6018T Brain, twice natural size, best execution, vertical and longitudinal section with open ventricles . . . . . . . . . . . . . . . . . . £1 10 0 )19T Five Sections of Brain, for demonstration, considerably enlarged, showing the different layers, all the ventricles opened . . . . . . . . . . £8 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 6020r Brain, natural size, wholly dismountable, very suitable for teaching purposes 6021 6022' 6023' 6024' 6021 The Half of a Head, on board, showing the superficial muscles, arteries, veins, nerves and glands Head, natural size, the left half exactly as 6021 ; the right one as 6023. The cavity of the skull is open, the brain divisible into eight parts, the base of skull shows all details . . Head, natural size, vertical section, showing the bones of the skull, cavities, cerebrum, cerebellum and medulla oblongata, nasal cavity, trachea, tongue, palate, resophagus, etc. Head with Neck, natural size, on stand, to be turned, divisible into many parts, showing all muscles, nerves and vessels on the surface and deeper, besides the structure of bones, after removing of the muscles. Eye removable £2 19 6 £0 16 6 £620 CROSS STREET • HATTOTSr GARDETST, EvC 1100 BAIRD &TATLOCK (LONDON) LTD. 6025T Model of Head showing the nerves. 6025 This model consists of the half of a. natural cranium, which is so prepared and opened that the course of the twelve brain nerves is easily seen. The eyeball with its muscles and nerves is shown, as well as the carotis interna and vena jugularis communis, the nose muscles are preserved. The upper and lower jaw are opened for studying the n. trigeminus. A very instructive model also for studying the brain nerves, particularly to be recommended to students of dental surgery. Price £6 17 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1101 BAIRD &TATLOCK (LONDON) LTD. 6026 6027 6026' Left Half of the Head on Stand, showing besides the median section the muscles, arteries, veins, nerves and the parotis with its passages. New instructive model £3 3 60271 Half -Head on Stand, specially suitable for the study of teeth and jaws. Highmor-cavern and lower jaw-channel opened. All the teeth are visible as well as the conducting nerves and vessels, the articulation of the lower jaw, the masticatory muscles, the salivary glands, the nose muscles are also to be seen. Newly modelled according to the indications of Prof. Dr. Benninghoven. This model may be specially recommended to students of dental surgery £360 -CROSS STREET • HATTCW GARDEK, E-C BAIRD &T201OCK (LONDON) LTD. 6028 6028T Ear, thrice enlarged, dismountable with pinna, showing the interior disposition £120 Outside view of the inner part. 6030 6030T Ear, five times enlarged, modelled at the First Anatomical Institute in Berlin. On stand, with 315 names printed on . . . . . - • • • • • . . . £15 0 0 Consisting of sixteen parts, divisible into two principal plains : 1 . Into a section through the exterior and interior ear passage. 2. Into a section through the Eustachian tube and the mastoid process. Both sections meet in the tympanum socket just in the joint between anvil and stirrup. .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD cVTATLOCK (LONDON) LTD. *• This yields four main pieces : I. Mastoid part with whole tympanum, chorda tympani, hammer and anvil bones. II. Jaw-joint part with a. maxillaris interna and the third branch of trigeminus. III. Vertebral column part with large vessels, nerves, the labyrinth and the stirrup bone (stapes). IV. Pharynx part with ganglion seminulare (Gasseri) and the Nn. petrosi. As a whole the model shows on the outside the exterior ear, on the inside that part of the cranium which contains the 3rd — izth brain nerve, the n. suboccipitalis and the a. vertebralis ; in front the pharyngeal space, behind a section through the back of the head. In detail, Part I. shows the tympanum (Piece 5) removable with exterior and interior tympanum folds and pockets ; the cranial part (main piece) shows the descending part of the n. facialis and its division in the parotis, further a vertical section of the concha and the exterior cartilaginous and bony ear-passage with the different curves. Part II. shows the exterior part of the concha with the m. tensor veli palatini and in front the chorda tympani in connection with the n. lingualis. Part IV. shows the back part of the pharynx with the tube opening them, levator veli palatini, the m. tensor tympani, Ganglions emilunare (Gasseri) , Ganglion oticum, the upper pharynx-muscles and vessels. Part III. is very complicated, because it contains the labyrinth. When the tegmen tympani is lifted up, after the whole model has been put together, one gets a view into the antrum tympanicum and the tympanic cavity with the little ear bones. Then the cover of the interior ear passage (Part 7) and the n. facialis and acusticus (Part 8) and further the cover for the upper and back semicircular canal can be removed. Also the connecting piece between the cochlea and saccus endolymphaticus is movable (Part 10). The closing plate of the interior ear-passage with the exterior and interior openings for the branch of n. acusticus (aerae et maculae cribrosae, recessus ellipticus, etc. , as Part II.) can be removed. The labyrinth can be removed as a whole as also its bony boundaries (plexus tympanicus [Jacobsoni] fenestra ovalis and triquetra, v. canaliculi cochlea), particularly for the demonstration of the bulbus superior of the v. jugularis interna. For this purpose, moreover, the bone-cover above the emissarium condyloideum posterius (Part 24) is to be removed as well as in front the a. carotis interna with the large nerves (Part 15). The base-part shows internally the opened sinus sigmoideus, outside the same dissected to show the emissarium mastoideum, the exterior and back semi-circular canal and the saccus endolymphaticus. The model can be obtained with the stirrup bone (Part 16) either removable or fixed as desired. The proportions, the dimensions, etc., of the various parts are modelled according to Schwalbe's " Lehrbuch d. Sinnesorgane." The model is about 45 cm. high, 65 cm. long, 60 cm. wide, and is spoken of by some of the greatest authorities as a first-class model for teaching purposes. 60321 Preparation with Nerves and Muscles of Tongue and Ear (tongue and the organ of hearing in natural size). The opened os temporale shows the whole interior mechanism of hearing. Very instructive preparation (see 4h) . . 6033T Tongue, dismountable, natural size 6034r Nose, considerably enlarged, represented in two halves. One part represents the bridge of the nose, the other the external wall, turbinated bones, etc. All the arteries, nerves and veins are visible. Very instructive preparation 60351 Three Horizontal Sections of the Head modelled from nature (Prof. Frankel). The sections give a true image of the nasal cavity and of all the adjacent parts. Instructive and scientific preparation SKIN. 6036T Vertical Section through the Skin, 200 times enlarged, showing the three principal layers, sebaceous and sweat glands, hair roots, muscles, arteries, and veins \ . . ORGANS OF RESPIRATION. 60371 Larynx, natural size, with muscles, divisible into two parts . . 60381 Larynx, natural size, with cartilages and ligaments, divisible into two parts . . £3 17 £0 8 £2 2 £360 £0 12 . £086 £0 10 6 • CROSS STREET - HATTOTST GARDEN, E- C it BAIRD &.TATLOCK (LONDON) LTD. .U 6040 6039 6043 6042 60391 Larynx, twice natural size, with muscles, cartilages, and arteries, showing the trachea down to the bifurcation. The different muscles are dismountable . . . . . . £120 6040T The Cartilages of the Larynx. This model is totally dismountable, the vocal chords are removable. Very instructive preparation to illustrate the production of the different sounds UT Larynx, natural size, showing besides the muscles and ligaments the vessels, nerves, and thyroid glands, best model for physicians Heart, natural size, to be opened. Most perfect execution, modelled from nature ; best model for physicians and students Model, showing the circulation of blood, half natural size • Lymphatic Glands of the inguinal region with their veins. New model Trunk, natural size, with head, the brain divisible into eight parts, the lungs into two parts. The larynx is dismountable and divisible into two parts. All abdominal intestine are removable, with thoracic and abdominal wall FEMALE MODELS. Model of a Female Figure, natural size, standing on a polished pedestal. This model shows on the right exterior side the superficial muscles and the principal arteries. The head is isible into three parts by a cross section and by a median section. Thereby the nose cavity, the nose diaphragma, : throat cavity, the section of the larynx as well as the spinal marrow are visible and the brain which is divisible i its principal parts can be removed. After the removal of the front wall of the thorax and the abdomen the irior organs are visible. They can be removed one by one, i. 1. : both lungs, the heart which is dissectible, the phragm, the liver, the stomach with the pancreas, the spleen, the small and large intestine and the uterus with bladder. In the thoracic, abdominal and pelvis cavities the arteries, veins, and nerves are shown, the thymus is aible. The urinary organs are also shown. The model is made with greatest care. £176 £176 £2 £1 2 7 £0 17 0 6 6 £920 Price £55 0 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 1105 ti^Sfc, BAIRD dcTATLOCK (LONDON) LTD. SECTION No. 23. Meteorological Apparatus. 6050-6051 6052-6053 6050s Anemometer, with two dials, reading to 1,000 ft., with disconnector in mahogany case . . £2140 6051s Anemometer, with six dials, reading to 10,000,000 ft. . . . . . . ..£300 6052s Anemometer (Biram's), 3 in. ; with two dials, reading to 1,000 ft. . , . . £2160 60535 Anemometer (Biram's), 6 in. ; with four dials, reading to 100,000 ft. . . • . . . . £340 6054 6055 6504s Anemometer, Robinson's, with enamelled dial, reading to 500 miles, hands adjustable to zero . . . . • 6055s Ditto, ditto, with fixed points, N. S. E. W., and weather vane £3 10 0 £6 10 0 CROSS STREET • HATTO>T GARDETST, E-C BAIRD&TXTLOCK(LOW)ON)LTD. gfi$| $ • •', .•'"'.'•"" V: .• Section XXIII ffl* SSI - » BBVESSG Anemometers 1106 Barometers ygrometers 1107-1114 1121-1123 Rain Gauges 1115-1117 Sunshine Recorders Thermometers 1118-1120 and 1124 14 CROSS STREET. HXTTON GARDEN" EC BAIRD &L TATLOCK. (LONDON) LTD. The following are the different Sections in oui Catalogue. Those marked * are also printer separately. Section No. 1.* Laboratory Fittings 2.* Bacteriological Apparatus Chemical Physiology Apparatus Microscopes and Microscopical Accessories Balances and Weights Chemical Apparatus Botanical Apparatus Gas Analysis Apparatus Milk Analysis Apparatus Refractometers Oil Analysis Apparatus Water Analysis Apparatus Cement Testing Apparatus Leather Testing Apparatus Paper Testing Apparatus Physico Chemical Apparatus Pyrometers Calorimeters Seed and Soil Analysis Apparatus Spectroscopes and Polariscopes Volumetric Apparatus Anatomical Models Meteorological Apparatus Assay Apparatus Chemicals 3. 4." 5.* 6.* 7.* 8. 9.* 10. 11." 12. 13. 14. 15. 16. 17.* 18.* 19.* 20.* 21. 22. 23. 24.* 25.* Pages Nos. 14.56 57^161 162. 192 193.320 321.382 383.816 817.842 843.886 887.894 895 . 90: 903.9; 927.93: 934. 94< 947 . 949 950.951 952.976 977.1006 1007.1022 1023.1042 1043.1078 1079.1087 1088.1105 1106-1124 1125.1172 1187.1246 14 -CROSS STREET • HATTCTN GARDEK, EC BAIRD &.TATLOCK. (LONDON) LTD. 6056 6057 6058 6059 6056s Barometer, Bunsen's, syphon tube, graduated into millimetres, filled with mercury, and mounted on mahogany stand, with mirror back to avoid parallax when reading 6057s Barometer, Bunsen's syphon, with plain tube and sliding millimetre scale on polished mahogany board for direct reading, suitable for school use I 6058s Barometer, designed by Mr. Gee, with boxwood millimetre scale and two sliding points . . 5 6059s Syphon Barometer, consisting of an ungraduated Bunsen syphon tube, filled with mercury and mounted on a polished mahogany board fitted with a sliding millimetre scale for direct reading. The necessary adjustments and readings are made on the scale by means of two sliding indexes fitted with cross wires, and mirror backings at the upper and lower surfaces of the mercury column. This barometer is of thoroughly reliable construction, and as the height of the column can be read with fair accuracy to .1 mm., it is suitable for all ordinary purposes. The tube used in the instrument is provided with an air-trap 6060s Barometer, with ivory scale, sliding vernier, thermometer, and adjusting screw on polished oak frame 6060 £1 5 £1 5 » £0 16 & £1 12 £1 1 0 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LOM)ON) LTD. 6061 6063 6064 6061s Barometer, Pediment, carved frame 6062s Barometer, Pediment, small size 6063s Barometer, Pediment, chaste carved, bold tube, engraved ivory scale, two verniers, and thermometer 6064s Barometer, Fitzroy's, two sliding indicators, with thermometer and storm glass 6065s Barometer, Fitzroy's, strong carved Gothic frame, double indicator, rack and pinion adjustment £550 £0 17 6 £1 10 0 CROSS STRET • HATTOTST GARDEN, E- C 1108 BAIRD 114S The Wilson Self -Registering Dial Rain Gauge, showing 10 in. rainfall, 8 in. square copper Self-Recording Rain Gauge, case of japanned steel, hinged upon iron base, dimensions 12! by 17 by /f in. il!5s Price, totalising to 10 in. >1165 „ ,, 200 in. (Each gauge supplied with one year's charts, ink, and pen.) The above illustration shows the Self-Recording Rain Gauge. The instrument is self-contained, and the :ion is fully protected from the elements. The clock drum completes its revolution weekly. The chart is arranged to show I in. of rain from top to 'om, and is sub-divided into tenths and TVths, the pen, however, marking each rJnjth. s dial or totaliser shows i in. on the outer circle, sub-divided into tenths and hundredths, and the smaller I registers up to 10 in. Also made with a third dial up to 200 in. for tropical use. The case is made of japanned steel, hinged upon an iron base. The diameter of the brass rim on funnel is 8 in. 117s Campbell-Stoke 's Sunshine Recorder, best make, on polished slate slab 118s Charts for above for one year . . . . . . . . £3 10 0 £10 10 0 £12 12 0 £9 15 0 £1 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1117 BAIRD &. TATLOCK (LONDON) LTD. 6119 6119T Hygrometer, self-recording, in copper cover and iron base, j-day revolving drum. The hygrometric portion can be fixed outside as shown, or inside copper cover, complete with two coloured inks and one year's charts .. .. .. .. .. .. £7 15 6120 6120s Thermograph, or recording thermometer, in all metal frame and hinged copper cover, as illustrated, with charts for one year . , . . . , . . . . . each £4 17 6 i 1118 BAIRD .kTATLOCK (LOM)ON) LTD. 6121 6124 6126 6128 each 6121 Thermometers for walls, etc., plain wood, polished, 8 in. . . . . . . each £0 6122 Thermometers for wall, boxwood, 12 in. .. .. .. .. .. ,, £01 6123 Thermometers, for walls, etc., polished boxwood, English make, 8 in., deg. F. scale perdoz. £0 12 6124 Thermometer, wet and dry bulb (Mason's hygrometer), boxwood scale . . each £0 10 6125 Thermometer, wet and dry bulb (Mason's hygrometer), polished zinc scale .. „ £011 6126 Thermometer, wet and dry bulb (Mason's hygrometer), opal glass scales on polished oak board, standard pattern, with National Physical Laboratory Certificate . . . . £115 6127 Ditto, ditto, without Certificate .. .. .. .. .. .. .. £112 6128s Hygrometer, Mason's standard, for the determination of humidity in cotton factories as required by Home Office regulations, with Certificate as figured . . . . . . £110 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &_ TATLOCK (LONDON) LTD. Wet md dry Bulb Thermometer. 6129 6134 The " Demonstration " Set of Thermometers and Screen. 6129 The Screen illustrated above is designed for the use of observers who have not the con- venience for setting up the ordinary full size Stevenson's Screen. As will be seen, the apparatus is easily fixed upon a wall or post, and the thermometers are specially made in a reduced size, whilst still of standard accuracy. The screen is designed to allow of the correct observation of shade temperatures. It is well made, and painted white. The thermometers, are graduated upon the stems, figured upon the opal scales, and well mounted upon seasoned oak slabs. Price complete with thermometers as illustrated . . Prices Separately. 6130 Screen 6131 Wet and Dry Bulb Thermometer 6132 Maximum Thermometer 6133 Minimum Thermometer 6134s The " Peandar " set of Meteorological Instruments. Of standard accuracy, eminently suited for use in small observatories, schools, and for private observers. Set, comprising — " Student's " Standard Barometer, Fig. 6098 (Rd. No., 420297), diameter of mercurial column .25 in. graduated with inches and metric scales, with verniers reading to .01 in. and i millimetre. On polished mahogany or oak back board, with opal glass reflectors and screws for vertical adjustment. Standard Mason's wet and dry bulb thermometer, oak frame, engine divided tubes, figured on opal glass scales. Copper water reservoir and tables. Standard maximum thermometer, oak frame, engine divided tubes, figured on opal glass scale. Standard minimum thermometer, oak frame, engine divided tubes, figured on opal glass scale. Copper Snowdon rain gauge, complete with graduated glass measure. Meteorological Register for one year. Price complete N.B. — All the above instruments in the above set will pass the National Physical Laboratory test. National Physical Laboratory Certificates, if desired, £1 12s. 6d. extra. £2 15 £0 16 £0 19 £0 10 £0 9 £660 1120 BAIRD ^TATLOCK (LONDON) LTD. The^Hygrodeik. 6135-6137 6138 The Hygrodeik is an improved form of the Mason Hygrometer, consisting of two thermometers (wet and dry bulb) , mounted upon the outer edge of a chart plotted from standard wet and dry bulb tables. The Mason Hygrometer, while invariably recognised as the most accurate and satisfactory of the many forms of Hygrometers in use, has never enjoyed the popularity which its merits deserve, owing to the annoying necessity of reference to complicated tables for determining the Relative Humidity and Dew Point corresponding to the ditii ronce in degrees between the wet and dry bulb Thermometers at different temperatures. The Hygrodeik charts, while complicated in appearance is simplicity itself, and obviates entirely the use of tables for temperatures between 20° and 180° F. DIRECTIONS FOR READING THE HYGRODEIK. To find the Relative Humidity. Swing the index hand to the left of the chart, and adjust the sliding pointer to that degree of the wet bulb thermometer scale at which the mercury stands. Then swing the index hand to the right until the sliding pointer ersects the curved line which extends downward to the left from the degree of the dry bulb Thermometer scale dicated by the top of the mercury column in the dry bulb tube. At this intersection the index hand will point > the Relative Humidity on the scale at bottom of Chart. For example (see illustration), should the temperature dicated by the wet bulb Thermometer be 60° and that of the dry bulb 70°, the index hand will indicate humidity "" when the pointer rests on the intersecting lines of 60° and 70°. To find the Dew Point and absolute amount of Grains. Observe the intersection as above, and follow the curved line (passing through it, which runs from the top downward to the right) to the point of contact with the dry bulb scale. The degree (53) at this point on that (scale is the dew point required. The figure at the upper end of this line will give the absolute amount of water I in grains (4.5 grains) per cubic foot of air. 6135s Hygrodeik, mounted on japanned iron frame, with base for standing . . . . each 6136s Hygrodeik, mounted on polished brass frame, with base for standing . . . . ,, 6137s Hygrodeik, designed to hang on wall ; strong hanger at top and in place of base, made with brass cistern, mounted on polished brass, or brass nickelled frame . . each High Range Hygrodeik. — The above hygrodeiks can be supplied with range 20° to 120° or So0 to 180° F. 6138s The Pagoscope. A Frost Predictor A device for foretelling, early in the evening, whether there is or is not to be a frost during the following might, has been devised by a French meteorologist. It accomplishes its purpose by ascertaining whether or not the dew point, or point where the deposition of moisture from the atmosphere begins, is near, together with a sufficiently low temperature to insure that the moisture shall be deposited in a solid form. The familiar device [pf a Wet Bulb Thermometer is employed, the rapid evaporation of water from the moistened bulb lowering the temperature, and the more so as the air is drier and farther removed from the dew point. An ingenious mechanical [contrivance obviates the necessity of the usual mathematical calculations. This new instrument is, as may be extremely simple and of real practical interest for fruit growers, gardeners, and farmers in general. £1 £2 £200 £100 MCAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1121 BAIRD &TATLOCK (LOM)ON) LTD. 6139 6139s Negretti & Zambra's Horticultural Hygrometer (Registered Design No. 507313). An instrument for ascertaining in a simple manner the likelihood of a frost during the night. The Hygrometer is an instrument for determining, with the aid of special tables, the relative humidity of the atmosphere and the dew point. The late Dr. Buchan, in his text-book, remarks that in the evening " the dew point determines the minimum temperature of the night," and if this dew point be below freezing point, it is only fair to presume that there will be a frost during the night. In the majority of cases there are no signs to indicate that the dew point is below 32° F.. as, for example, with an air temperature of 60°, the dew point will be below freezing point if the wet bulb temperature be 44° or less. The object of the Horticultural Hygrometer is therefore to show in a simple manner, without the use of tables, whether the dew point is below freezing, and consequently whether frost may be expected. We need hardly point out to horticulturists and agriculturists the importance of detecting the arrival of frost, whether it be an Early Winter Frost, or a Late Spring Frost. One should have some means of knowing whether to take the necessary steps for the protection of valuable plants, crops, fruit trees, etc. The Instrument is a wet and dry bulb Hygrometer, with a special cylindrical scale revolving between the thermometers. The cylinder is figured in three sections, which are intended to apply as follows : — White Section : Frost highly improbable. Shaded Black It will be seen that the cylinder has ten lines, numbered i, 2 degrees between the readings of the wet and dry thermometers. The Method of Observing is as follows :— The instrument must be placed in the open air, but in such a position that the sun's rays do not fall upon it. The observation should be taken as late in the evening as possible. Upon arriving at the instrument, note at once the dry bulb reading — note the wet bulb reading, and the difference between the two. Turn the cylinder (by means of the handle) until the line and figure representing this difference is at the right-hand side of the opening. Look down the scale on the right-hand side of the opening, and the wet bulb reading (just observed) will fall opposite one of the three sections. From this the observer knows whether frost is likely to occur during the night. AN EXAMPLE. The dry bulb reads . . . . . . . . 41 deg. The wet bulb reads . . . . . . . . 36 deg. £1 1 Frost doubtful. Frost very probable. 3, 4, up to 10 ; these represent the difference of Difference . . . . . . 5 deg. The 5 line along the right edge of the opening and 36 deg. (wet bulb) reading comes opposite the black section : hence a probable frost. CROSS STREET • HATTO>T GARDEN, E-C a-f BAIRD &TATLOCK (LONDON) LTD. 6140 6f41 6140 Hygrometer, Daniell's 6141 Hygrometer, Regnault's, with two silver condensation tubes, two thermometers, stand, and copper aspirator, as illustrated 6142 Hygrometer, Regnault's, cheap form for school use, consisting of a glass jar about 6 in. by i in., round the bottom of which is a band of silver foil. A thermometer is inserted through a cork, and a small tube through the same cork for breathing to cause evaporation. It is used in the following manner : Pour in sufficient ether to cover thermometer bulb, blow down small glass tube ; a rapid evaporation is thus produced, dew is formed on the silver, and the thermometer indicates the dew point £0 10 6 £4 10 0 £050 - 6143 6144 >143 Thermometer, maximum and minimum, horizontal pattern, on polished boxwood back with hooks for affixing to wall . . . . . . . . . . . . each • 144 Thermometers, Six's maximum and minimum with 10 in. metal scale, in japanned frame, with magnet best English make • 145 Thermometer, Six's maximum and minimum, as above, but graduated to 220° F. '146 Thermometer, maximum and minimum, mounted on same board, maximum tube with indestructible index £0 11 0 £0 10 £0 12 0 6 £0 11 6 1123 BAIRD &TATLOCK. (LONDON) LTD. 6147 6147 Thermometer, terrestrial radiation, registering minimum, on stand . . 6148 Thermometer, solar radiation, with black bulb £0 16 0 £0 12 6 6149 6150 6149 Apparatus for measuring the flow of water in streams and rivers, etc. 6150s Thermometer Screen, Stephenson's, on stand 6151 6151 Thermometer, solar radiation, with black bulb in vacuo, on stand with tripod base £140 1124 BAIRD &TXTLOCK (LONDON) LTD. SecTio>r XXIV ssffi MINING, METALLURGICAL, SURVEYING APPARATUS Blowpipe Sets Crucibles /•*• i Crushers Cupels and Cupel Machines Furnaces Mills Mortars Moulds Samplers Sieves Tongs Washing Pans Surveying Instruments Pages. 1125-1127 1129-1130 1131-1133 1134-1135 1136-1141 1146-1149 1151-1152 1152-1153 1155 1157-1159 1160-1161 1142 1162-1172 14- CROSS STREET. HATTON GARDEN E.G. raHi? «2^ ^£> ar iram $^c~2&& ^ <^j The following are the different Sections in our Catalogue. Those marked * are also printed separately. Pages Nos. Section No. 1.* Laboratory Fittings 14-56 * » 2.* Bacteriological Apparatus 57-161 »> 3. Chemical Physiology Apparatus 162-192 » * 4.* Microscopes and Microscopical Accessories 193-320 i * 5.* Balances and Weights 321-382 »> 6.* Chemical Apparatus 383-816 t » 7.* Botanical Apparatus 817-842 *» 8. Gas Analysis Apparatus 843 - 886 >» 9.* Milk Analysis Apparatus 887-894 tt 10. Refractometers 895-902 > » 11.* Oil Analysis Apparatus 903 - 926 1 » 12. Water Analysis Apparatus 927-933 ) » 13. Cement Testing Apparatus 934-946 » » 14. Leather Testing Apparatus 947-949 tl 15. Paper Testing Apparatus 950-951 » » 16. Physico Chemical Apparatus 952 - 976 * * 17.* Pyrometers 977-1006 99 18.* Calorimeters 1007-1022 99 19.* Seed and Soil Analysis Apparatus 1023-1042 t » 20.* Spectroscopes and Polariscopes 1043-1078 ft 21. Volumetric Apparatus 1079-1087 f » 22. Anatomical Models ' 1088-1105 » * 23. Meteorological Apparatus 1106-1124 >» 24.* Assay Apparatus 1125-1172 99 25.* Chemicals 1187-1246 BAIRD &TATLOCK (LONDON) LTD. SECTION No. 24. Assay, Mining, Metallurgical Apparatus and Surveying Instruments. 6152-A6152 B6152 6153 6154 6152 Anvil, steel slab, 2 by 2 by i in., polished one face . . .\6152 Anvil, steel slab, 4 by 4 by i in., polished one face . . B6152 Anvil, steel for flattening small buttons (Ross' mortar) 6153 Anvil, or " Beck Iron," polished face, best steel. Weight . . . . . . | i ii Ibs. Length about . . . . . . 4 4* 5 in. Price .. ..' .. 4/- 5/- 6/- each. 6154 Anvil, or " Square Stake," polished face, best steel, with fang. Weight . . . . . . ij 2 3 Ibs. Size of face about . . ' . . . . ij ii 2 Price .. .. .. .. 3/- 4/- 61- i!55 Asbestos Cord SOCIETY OF ARTS BLOWPIPE APPARATUS. \6155 The Elementary Student's Set, in deal box .. .. .. .. . . £0 10 6 CONTENTS. — Blowpipe, hammer, anvil, grease lamp, spirit lamp, scissors, lamp tweezers, brass tweezers, Inagnet, cupel striker, pastille holder, pastilles, platinum wire, tinfoil, boiling dish, litmus paper, turmeric paper, Brazil wood paper, open tubes, closed tubes, glass rod, carbonate soda, micro salt, borax, bisulphate of potash, jiluor spar, assay lead, bone ash, nitrate of cobalt. 36155 Lieut. -Col. Ross's Pyrological Cabinet, in polished mahogany case .. .. £3 10 0 CONTENTS. — Ross's blowpipe, oil lamp on stand, spirit lamp, anvil mortar, platinum forceps, steel forceps, luminium plate and holder, charcoal slips, platinum wire, agate slabs, pliers, tube holder, magnifier, charcoal j jaw, magnetic needle, knife, slip of blue glass, closed tubes, glass tubing. Reagents — Nitrate of cobalt, stick i.lacial acid, carbonate of soda, carbonate of potash, lime, borate, tungstic acid, rutile, bisulphate of potash, potassic :3dide, sulphur, litmus paper, turmeric paper, Brazil wood paper, magnesium ribbon. (Similarly packed to Fig. 6156.) 3l in. sq. 18/6 each. . . per yard £004 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1125 BAIRD &.TATLOCK. (LONDON) LTD. 6156 6156T Blowpipe Apparatus, Prize Set, in stained deal box . . . . . . . . £15 CONTENTS. — Blowpipe, spirit lamp, grease lamp, hammer, anvil, pestle and guard, platinum forceps, brass forceps, lamp tweezers, test tube holder, chisel, magnet, file, scissors, cupel striker, bone spatula, platinum wire, platinum foil, tinfoil, magnesium, pastille and cupel holder, pastilles, boiling dish, open tubes, closed tubes, glass rod, blue glass, litmus paper, turmeric paper, Brazil wood paper, soda paper, carbonate of soda, microcosmic salt, borax, bone ash, fluor spar, assay lead, nitrate of cobalt, bisulphate of potash, oxide of copper, chloride of silver, potassic iodide and sulphur. 6157T Superior Set, in polished mahogany box, with initial plate, contains in addition to the above — Platinum nozzle to blowpipe, agate mortar and pestle, and gold bead . . . . £115 6158T Best Set, contains same apparatus as set No. 6157, in mahogany box, with the addition of forty-eight carefully selected test minerals in tubes arranged in a drawer. These minerals afford good examples in practice for both elementary and advancedtstudents . . £25 6159 61591 Campbell's Prospector's Set, in stained deal box .. CONTENTS. — Blowpipe, charcoal, forceps, platinum wire, spirit lamp, grease lamp, tube holder, funnel, pestle and mortar, magnet, watch glass, filter papers, test tubes, quartz crystal, sapphire, topaz. Reagents — Hydrochloric acid, sulphuric acid, nitric acid, tartaric acid, spirits of wine, ammonia, cobalt nitrate, borax, sodium carbonate, potassium cyanide, potassium ferrocyanide, stannous chloride, bismuth nitrate, caustic potash, ferrous sulohate, quicklime, common salt. £2 5 0 14 -CROSS STREET • HATTCTK GARDEK. E-C 1126 BAIRD &.TATLOCK (LOM)ON) LTD. 6160 6160s Baird & Tatlock's Set of Blowpipe Apparatus, in varnished pine box. Outside measurements, gf by 6f by 4 in. . . . . . . . . . . each CONTENTS. — One hammer with chisel end, one grease lamp, one block compressed charcoal, one small agate mortar in wooden block, one pestle for ditto with wooden handle, two porcelain crucibles, one piece platinum foil - by i in., one 3-in. horseshoe magnet, one lens for magnifying, needle for cleaning blowpipe nozzle, one aluminium uljlimate plate, one pair nickel-plated forceps, six 6-in. lengths glass tubing, one Black's blowpipe, one tin spirit amp, one steel anvil, one hundred niters 2 J in., one box extra wick for spirit lamp, one piece platinum wire 4 in. ong, one pair cutting pliers, one book blue litmus paper, one pair forceps with platinum points, one zinc plate, 12 in. thin copper wire, twelve bulbs and arsenic tubes. Turned Wood Boxes containing — Sodium carbonate, >orax, sulphur, copper oxide, microcosmic salt, fluor spar, lead grain. Bottles containing — Phosphoric acid, obalt nitrate solution, potass bisulphate, boracic acid, tinfoil, £160 6161 6161 (packed in iase) )161S Prospector's Ivory Density Rule and Scale of Hardness, suitable for prospectors or explorers. Price in japanned tin box ,with,divisions DESCRIPTION. The density rule is a very light and convenient little instrument, no larger than a pencil, that may be carried n the pocket without inconveniencing the traveller, and together with the accompanying scale of hardness gives iumcient data for the identification of a large number of minerals. To make a density determination, select a specimen somewhat over 10 grammes in weight ; place the brass •ob with the index marks at zero on the density and millimetre scales ; suspend the specimen by a horse-hair r silk thread from the other arm, at any point where it will exactly counterpoise the bob, and fix it there, which lay conveniently be done by having a running loop on the horse-hair. Now immerse the specimen in water, and love the brass bob back until it again counterpoises the specimen. On the density scale the index of the bob will how the density of the specimen, with accuracy to the first place of decimals for any ordinary specimen, from a ensity of from 2 to 5. From 5 up to 10 it will read to half a unit, and thereafter it is only approximate. £1 1 0 1127 Cr i BAIRD &TATLOCK (LOM)ON) LTD. .u 6162 6163 6162 Brushes, metal bristles, for burnishing 6163 Brushes, flat, for cleaning bucking boards, 4-in. bns 6164 Brushes, round, for cleaning mortars and crushers, etc. 6165 Brushes, soft hair, for cleaning silver, etc. (jewellers' brushes). 3 4 lOd. 1/2 1/9 6164 each £0 £030 £046 8 rows. 2/6 each. 6166 6167 6166 Burner for burning petroleum vapour without wick, of polished brass. Capacity 2\ pints 6167 ./Etna Paraffin Lamps. These burn without smoke or smell. Flame can be easily regulated. Size . . . . No. 3 No. 4 No. 6 With vertical burner. With vertical burner. With horizontal burner. Capacity .... 2 i i pint. Price .. .. 17/6 15/- 15/- each. See Nos. 3457-3462 for Petroleum Burners. 14 -CROSS STREET • HATTOTST GARDEN, E'C- 1128 BAIRD &TATLOCK (LONDON) LTD. 6168 6169 6170 6172 61685 Petroleum Lamp, " The Sunrise," with 4! in. burner, height loj in., width j\ in. . . £046 6169= Petroleum Lamp, " The Sudan," with 2 by 4^ in. burners, height n£ in., width j\ in., length Si in. . . . . . . . . . . ... . . ..£076 61705 Petroleum Lamp, " The Twin Albion," with 2 by 4^ in. burners, height 13 in., width 10 in. £0 13 6 6171s Chamois Skins, price according to quality 6172s Chisels for cutting metal each, 21-, 2/6, and £036 each £0 1 0 6173 6178 Crucibles, Morgan's Salamander. Do not absorb moisture. Not affected by frost. Each number contains about 2 Ibs. Thus No. 20=40 Ibs. capacity. 6173T Crucibles, Nos. Each Per doz. 61741 Lids, per doz. 6175r Crucibles, Nos. Each Per doz. 6176T Lids, per doz. i6177r Crucibles, Morgan's Plumbago. (Same sizes and prices as Salamander, No. 6173.) 6178r Crucibles, clay, " Battersea round." oooo 000 00 o i 2 3 4 5 2d. 2d. 3id. 3|d. 4|d. 8d. l/- 1/4 1/8 1/9 21- 2/9 3/6 4/- 8/- 11/6 15/6 19/- 1/1 1/3 1/6 1/9 2/3 2/9 3/6 4/6 5/6 . . 6 8 10 12 14 16 18 20 2/- 2/6 3/- 3/9 4/2 5/- 5/6 7/- 231- 28/- 34/- «/- 48/- 58/- 60/- 70/- 6/6 8/6 10/6 12/6 14/6 16/6 18/6 20/- Size A B C D E F G H J K L M N O Height 2 8 3 3i 4 4i 5 5l 5% 6| 7i 8 8| 9l 10 in. Diameter ll ij 2i 2f 2* 3 3l 3! 4i 4l 5i 51 6i 7 .. Per doz. 6d. 8d. lid. I/' 1/8 1/9 2/5 2/6 3/8 3/10 6/8 7/10 ll/- 16/6 179T Lids, per doz. ,<£S^ 8d. 8d. 8d. 8d. BT^r lid. -^gz^ 1/3 KBE 1/6 ffM\X- 1/6 vgq=as 1/10 2/5 2/5 3/- 3/8 ^ 4/2 S&Va CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. . IWM> I BATTEHSBA \ J \l ENGLAND 6180 6182 6184 6186 6187 6180T Crucibles, clay, " London round," as used by the London and Birmingham refiners. Size No. Height Per doz. Size No. Height Per doz. 61811 Flat lids for above. Size No. Per doz. Size No. Per doz. 6182T Crucibles, clay, Size Height Width Per doz. 6183T Lids, per doz. . , Sizes S, U, W, Y form in one nest and T, V, X, Z form in one nest.) 6184T Crucibles, for gold " annealing cups," perfectly smooth and correct porosity. Size . . A i£ by ] 2/6 9d. 6188 I 2 3 3i 4 4i 5 51 2| 2j 3f 31 4 41 5 5i m- 8d. lid. 1/3 1/9 1/10 2/5 3/- 3/8 6 6j 7 8 9 10 ii 12 6 6i 7 8 9 IO ii 12 in. 4/2 6/- 7/4 9/2 12/6 18/- 221- 28/- i 2 3 3i 4 4i 5 5i 8d. 84. lid. 1/3 1/3 1/6 1/10 1/10 6 6} 7 8 9 10 ii 12 2/5 2/6 3/- 3/6 4/- 4/9 5/6 8/- Battersea triangle." S T U V W X Y z 4i 4 3i 3i 2| 2* 2 if in. 4 3i 31 2i 2| 2j If if „ 2/6 1/10 1/4 I/- lOd. 8d. 7d. 5d. 1/10 1/10 1/6 1/3 lid. lid. 8d. 8d. Per doz. Lids, per doz. 61851 Crucibles, clay, for iron. Size B C Ji by ij i£ by i£ 2/6 2/6 9d. 9d. A B Sfbyii 3l by 2\ 1/2 1/4 ility, Juleff's. Sfbysi 2! by 2? * J o 2/6 1/9 D if by 2 in. 2/6 9d. C 4j by 2-f in. 1/9 by in. Per doz. . . 6186T Crucibles, clay, for copper, Cornish form and quality, Juleff's. Per doz. . . Crucibles, Royal Berlin Porcelain, " Annealing Cups," see Nos. 2326-2327. 61871 Crucibles, Battersea link, for assaying in reverberatory or other .furnaces. Size 3f by 3^ 4r\ by 3! 41 J by 4^ 5} by 4,"* in. Per doz. 2/6 3/3 4/9 5/10 6188T Crucibles, coal testing. Height fbyij f ; by if f by i| 2 by if in. Per doz. . . 2/6 3,1- 3/9 4/6 14 -CROSS STREET • HATTCXN GARDEN, E- C BAIR.D &.TATLOCKL (LONDON) LTD. 6189 6189 Crusher, bucking board, 2j by i8i in. inside, with pounder, clean castings, bucking board about i cwt. Weight of pounder about 21 Ibs. Weight of £1 15 0 6190 6190 Crusher, hand, for reducing ores to fine powder, side straps and grinding jaws of steel £500 Fig. i 6191 Fig. 2. 6191s The Weatherhead Combined Mortar and Pulveriser, an indispensable machine in every laboratory for reducing to an impalpable powder, in an incredibly short time, all substances from clay to pig-iron. This machine will pulverise all kinds of ores, coal, rocks, pig-iron, phosphate, clay, etc., and also for amalgamating gold ores. Weight, 100 Ibs. ; diameter, io£ in. ; height, 8£ in. . . . . . . . . ..£600 The Weatherhead mortar will do the work of two other machines, a rock- breaker and buckboard, or mortar, and therefore it is very cheap at price named. It will pulverise faster than any other hand machine ever Invented, as can be seen by referring to the undernoted tables. It s easy to clean, as there are no joints or corners for pulverised material to stick in. It revolves easier when pulverising material ian it does when empty. It is the only hand machine that discharges the material as soon as pulverised. No sieves need to be ised with this machine, as by passing the material through the second time, it will be reduced fine enough for all laboratory purposes, .hereby saving a great deal of labour and time sifting. The working surfaces are tempered as hard as steel can be tempered, .hereby minimising the wear. The machine has been in constant use for over five years, so that our claims for it lave been thoroughly demonstrated. The cover of the machine is made so that it can be used for a small hand mortar, the end if the handles being rounded to form a pestle. DESCRIPTION. A, cover. B, rotating pestle, c, casing or shell. D, handle, of which there are two. E, crushing post, which is corrugated nd slightly oval, producing great crushing power. F, conical currugated opening in centre of rotating pestle, where material is ntroduced. G, spout where material is discharged as fast as pulverised, n is one of four lugs on the side of rotating pestle, vhich carry the pulverised material to spout. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1131 r *,iXV*, ^*->i,' BAIRD & TATLOCK (LONDON) LTD. The operation is as follows : — The covering being removed, the coarse material is fed in at F, and pieces as large as will go in the opening can be crushed (unless of an exceptionally hard character). As the material is gradually crushed, it works down to bottom of conical opening, passing under the pestle where it is pulverised. The centrifugal force carries the product to the sides, where it is caught by the lugs H, which carry it to spout G, and discharge it. A number of these mortars have been examined that have been in daily use for four years or over, and are found to be in the same condition as when sold, no wear being apparent, only the knobs on the working surfaces being ground off a trifle, thus proving that it will' last a lifetime. The lines of the working surfaces are conscructed so that should there be any wear, they will always retain the same shape a? when new, be easy to clean, and every particle of material evenly pulverised B Fig. 3- 6191 Fig. 4. The above figure illustrates the crusher and pulveriser with both handles in position, making it very easy to lift out the pestle to clean the mortar. (Two brushes for cleaning are sent with every machine.) Another use for the handles in this position is when crushing very hard or large pieces of material, take hold of both" handles and work backward and forward (or see-saw), which will crush large pieces much easier.than with one handle, and as soon as the material is crushed sufficiently, take out extra, handle and go on with the rotary motion. Following are two tables showing the ordinary time required to grind one pound each of common window glass and plg-iro also showing the fineness of same after passing through pulveriser once. The pulverised product was then passed through series of six sieves. The per cent, remaining on each is shown in the following table : — GLASS. 40 mesh sieve 60 80 loo 120 140 Amount passed through 140 t per cent. 4 13 59 PIG-IRON. 40 mesh sieve 60 80 100 ,, I2O ,, 140 ,, Amount passed through 140 oo per ecu i 4i 9i 67 Total . . . . . . I0o Total . . . . . . 100 Time of pulverising . . . . . . 7^ min. Time of pulverising . . . . . . iz min. These tables are exact, and can be substantiated in every respect. The substances were selected on account of their common- ness, and the difficulty of pulverising them is well known. Taking into consideration their hardness, it will be readily seen with what ease ores, rocks, clays, and other substances can be pulverised to any degree of fineness with our No. i crusher and pulveriser. Showing rotating pestle lifted out and set on stand ready for cleaning. A wooden stand as shown in cut will be found very useful and convenient. It is simple, and can be made by any carpenter. When placed on stand the edge of the pestle should overlap the edge of the shell, so any material remaining on the pestle can be brushed off into the shell and then through the outlet. INSTRUCTIONS. The material to be pulverised must be dry, and should be broken in pieces about the size of a person's thumb; the harder the material the finer it should be broken. OPERATIKG. — Put proper amount of material, according to its hardness, into the hopper, then adjust both handles and work them back and forth (or see-saw), as by so doing you will get greater power, continue this until the larger pieces are crushed, then remove one handle and go on with the regular rotatory motion, same as turning a coffee mill, until the material has nearly all passed out of the hopper, then put in another charge and repeat the operation. It is customary with a great many users to return the material to the hopper a second time, and repeat the pulverising process, and then not use a sieve. 14 • CROSS STREET • HATTCTN GARDEN, E- C BAIRD <$tTATLOCK (LOM)ON) LTD. 6192 Simplex Ore Crusher is a hand-power machine, and is designed for crushing small samples of ore. We supply the same machine with broad wheel for 'belt for those desiring to use power. The advantages of this machine are : — The ease with which it may be opened for cleaning and the simplicity of its adjustment. Ono blow of a hammer loosens the wedge holding the non-vibrating jaw in place, allowing this jaw to be lifted out, thereby giving sufficient access for ordinary cleaning ; to further expose the interior of this crusher the vibratory jaw can be swung clear of its chamber without unloosening a bolt, screw, or nut, and without the use of a tool or wrench of any kind. The complete opening and closing again of this machine tor cleaning does not take one minute, not including the time occupied in cleaning. The fineness of the product obtained is regulated by increasing or diminishing the size of the discharge or lower opening of the jaws ; this can be accomplished by a few turns of the two regulating screws, which have hand wheels obviating the necessity for use of wrench. Can be adjusted to crush to a fine powder or the size of a coffee bean. When very fine crushing is desired, time will be saved by running ore twice through the machine, the first time set as wide as possible, and the last time at its maximum fineness. The parts of the Simplex Crusher which stand the strain are all sufficiently strong for the purpose, and the cost of repairs will be found to be less than one-half of the wear and breakage of other laboratory crushers. The steel jaw plates are reversible, removable, and renewable. 6192s Simplex Crusher, to be operated by hand, with two narrow wheels, 16 in. in diameter £8 15 0 6193s Simplex Crusher, to be operated by power, with one narrow wheel, and one wheel 3 in. wide for belt, both 16 in. in diameter .. .. .. .. .. £9 10 0 6194 (closed) 6194s Sample Grinder for hand-power, ball bearings, light running. one grinding an entire ore sample to any desired degree of fineness up to 200 mesh powder £12 10 0 6194 (open) It will pulverise with CHEMICAL AND SCIENTIFIC APPARATUS AND PURE C BAIRD &TATLOCK (LONDON) LTD. 61<>5 6196 WA7V V'l»|'t-i.-». i^v-i^un 4 Size No. i 2 3 4 5 6 7 8 9 10 Diameter f i ij zi Jl !$ IB ij 2j in. Absorp. grms Per doz. 3 8d. 5 8 9d. 9d. 10 16 lOd. l/- 20 28 1/6 2/6 40 4/6 J 56 3/- 106 15/- Per 100 51- 5/6 6/- 7/- 8/- 13/- 19/- 351- 60/- 100/- 6196s Cupels, " Mabor. " These have a greater absorption than bone ash and are not so fragile. Nos. I 2 3 4 5 6 7 S.A. 8 9 10 Diameter . . f J i IA ii Ils. iA IT* if 1 2fin. Absorp. grms Per 100 - 3 6 3/- 3/6 12 15 4/- 4/6 '^ 18 24 1 5/3 8/- 30 40 10/- 111- 50 12/6 1 65 90 25/- F.C. Assay, flat form, 12/6 MORGANtTE CUP! PATENT 6197 6 197s 'Patent Morganite Cupels. Size . . . . A Price per 100 . . 3/- Effective absorp. in grms. 3 Diameter at top . . f 6198-6199 6200 B 3/6 5 I C 7i i D 51- 10 E 6/6 15 F 7/9 20 if G 10/- 30 H ll/- 40 i| J 12/6 K 15/ 75 L 18/- 100 2 in. N.B. — These prices include all charges for wrapping, packing in boxes of 100 each (except sizes H, J, K, and L, which are packed in boxes of 50). 6198 Moulds for making cupels. For No. Malleable iron Gun-metal 6199 3 51- 7/6 5 6/6 121- 13/6 7 8 9 10 cupel. 8/6 9/6 10/6 121- each 14/6 16/- 17f- 18/6 „ 6200 Moulds for making cupels, with plunger sliding through ring so that cupels can be made of varying thicknesses. For No. .... 6 7 8 cupel. Malleable iron 91- 9/6 10/6 each. 14 • CROSS STREET • HATTCTNr GARDEN, E- C BAIRD (klATLOCK (LONDON) LTD. Wall Machine. 6201 Table Machine. 6202 Automatic Machine. 6203 6201- 6202 Cupel Machine for wall. This is a very practical and useful machine for making one size only of cupels. It is made for bolting to the wall or post, and occupies only a small space. A boy can easily turn out 100 perfect cupels in an hour. For making ij in. cupels | For making i| in. „ Price for any one size For making if in. ., ) When ordering, please state which size is wanted. Cupel Machine for table, for bolting to a table or stand ; very similar to the wall machine, but having interchangeable dies and plungers so that any size of cupels from J up to 2 in. can be made. Table cupel machine for making any one sized cupel Extra mould and die for any one size up to 2 in. 6203s Automatic Cupel Machine. Consists oi a compound lever, a plunger or die, and two discs. The upper disc contains the holes in which the bone ash is pressed, and the lower serves as the base. After compressing, the bottom disc is rotated until a hole in it is in line with the hole in the upper disc, in which the bone ash has been compressed. It is provided with automatic devices for stopping the disc at the proper points. There is also attached to this type of machine a hopper in which the moistened bone ash is placed. A strong wheel in the hopper bears on the upper disc and rotates as the machine is worked, thus preventing the moistened bone ash bridging in the hopper, and ensures a perfect automatic and uniform feed. Constructed so that cupels of various sizes can be made by changing the discs and All parts are interchangeable and adjustable. For making cupels from t to 2 in. Automatic cupel machine, any one size Extra disc and die, any one size In ordering, please state which sizes are wanted. £400 £5 £0 2 17 dies. £9 £2 10 10 6206 6204 6205 6204 Cupel Tray, sheet iron, with handle, 16 divisions 6205 Eye Protectors, with elastic band, blue glass 6206 Eye Protectors, with coloured glasses, in cases 6207 Eye Protectors, best wire, " Pillar goggles," blue glass 6207 £030 . per doz. £040 each £023 £050 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &.TXTLOCK (LOM)ON)LTD 6208 6210 6212 6208 Files, round, for enlarging holes in corks, etc., without handle, 5 in. each, 5d. ; per doz. 6209 Files, „ ,. ,. with handle „ ™- : 6210 Files, triangular, for cutting glass tubing and rod, etc., without handle, 3* in. each, 4d. ; 6211 Files, , with handle „ 6d. ; 6212 Files, flat form, without handles, 8 in. •• IJ*Jr • 6213 Files, „ with handles, 8 in. . . » ll* '• Flasks, Assay, conical, with ring and bulb flasks, etc., Bohemian glass. See Nos. 2715-2734. £049 £063 £039 £053 £0 10 6 £0 13 0 6214 62141 Furnaces, clay, portable Size iron bound, for 6215 melting gold, copper, etc. A B C Exterior dimensions 9l by 2of 9l by 23^ ii by 26 J in. For Morgan's crucible No. 2 4 6 Price, with fire-bars £150 £1 10 0 £1 15 0 each. Size g D E F Exterior dimensions 13 J by 29 J 141 by 31* i8i by 39 in. For Morgan's crucible No. 8 12 16 Price, with fire-bars •. . . £2 12 6 £3 10 0 £4 10 0 each. 6215T Furnaces, clay, for assaying, etc. Sizes AY AZ A B C Exterior dimensions Width and depth 8 9^ I2J '31 i4i Front to back Interior dimensions 1 Width and depth 9i 10 ii Front to back , For Battersea muffles a.y. & a.x. a.z.a. a.b.c.d. b.c.d.e. c.d.e.f.h. Price .. £100 £190 £25 0 £2 10 0 £2 15 0 each. Sizes D E F K Exterior dimensions- -Width and depth, front to back i5i i6J Iji 23 in. Interior dimensions — Width and depth, front to back 12 I2f I3| iq For Battersea muffles d.e.f.g.h. e.f.g.h f.g.h.j. k.l. Price . . £376 £40 0 £4 10 0 £900 each. /^&\^ IfJ 14 -CROSS STREET '• HATTCTN GARDEN, E-C- pS^S^ ~-K^JC ^t^° 1136 BAIRD &L TATLOCK (LONDON) LTD. 6216 Battersea Cupellation Furnace. This furnace has been designed specially for cupellation work and assaying. The sketch attached shows the accommodation for a Patent Battersea Muffle J. the inside dimensions cf •which are nf in. long by sj in. wide by 3! in. high, this being equal to the interior working space of a Rattersea Muffle J. Great economy will be found in using this furnace, as it is only necessary to use sufficient fuel to reach the level fof the floor of the muffle, the products of combustion then being sufficient to successfully cary out all metallurgical Japerations. The improved method of supporting the muffle insures a longer life to the latter. The furnace is fitted with draught regulator, so that the flow of air over the charges being treated can be \ ncreased or decreased at will. Free oxygen is introduced through the patent channels of the muffles simultaneously over the surface of all liie charges under operation, thus obtaining rapid and equal result s, and reducing the loss by volatilisation to a ^minimum. The height of the furnace is 24 in. ; width, 20 in. ; depth, 18 in. Total weight of furnace, 425 Ibs. Chimney, to Ibs. >216T Price of furnace 1>217T Patent muffle . . . . . . . . . . . . . . . . each N.B. — Furnaces of this type, to accommodate any size of muffle, can be made to order. £6 £0 5 0 5 6 1137 BAIRD &TATLOCK (LONDON) LTD. 6218 6222 6218T Furnace, the Morgan-Harvey, double muffle, for melting, assaying, etc. . . £5 6219T Price complete with chimney and elbow piece . . . . £6 10 6220T Price of extra linings complete 622 1T Price of extra muffles to suit .. .. .. .. .. •• each £0 4 This furnace has been designed to meet in a simple, durable, and portable form all the requirements of the assayer. It can be used for muffle or crucible work, and accommodates either two Battersea muffles J (12 by 6 by 4), salamander crucibles up to No. 30 (60 Ibs. capacity), Battersea round crucible P, or a number of smaller crucibles. The Morgan-Harvey furnace consists of stout sheet-iron casing, with cast-iron and fire-clay fittings, and lined with strong fire-clay slabs with rebated edges, ensuring tight joints, which are kept in position by the top plate being screwed down. The grate of the furnace consists of nine wrought-iron bars fitted diagonally into a cast-iron frame, and can readily be removed or cleaned ; the bars, being of ordinary size and section, can be renewed without difficulty. The covers are of fire-clay, iron bound, with falling handles to economise space in packing. When used as a muffle furnace it is so arranged that while the lower muffle is used for scoiification, cupellation may be carried on in the upper. To adapt the furnace for fusion work, remove muffles, block apertures with stoppers, and close doors. The furnace cannot get out of order, and as all fittings are movable they can be duplicated in case of breakage. The total height is 23i in. ; depth, back to front, i6t in. ; and width, i6l in. ; diameter of chimney collar, gin. 6222T Furnace, portable prospector's . . . . . . . . . . . . ..£40 62231 Price with chimney and elbow piece . . . . . . . . . . ..£50 6224T Muffles to suit . . . . . . . . . . . . . . . . each £0 4 This furnace has been designed to meet in a simple, durable, and portable form all the requirements of the prospector. It can be used for muffle or crucible work, and accommodates Battersea muffle J (12 by 6 by 4 in.), salamander crucible No. 20 (i.e., 40 Ibs. capacity), or Battersea crucible N. The furnace consists of strong fire-clay slabs with rebated edges, ensuring tight joints, which are kept in position by top plate being screwed down. The casing is of stout sheet-iron with removable fittings. FOR ASSAYING. The muffle door c is provided with a mica sight-hole through which the contents of muffle can be watched. The slab K is supported by the projecting ends of the fire-bars, and forms a convenient shelf on which to place the scorifiers, etc. FOR MELTING. The furnace can be used for crucibles by closing the muffle aperture with the clay stopper N, and the contents of the crucible can be inspected from time to time through the sight- hole A, thus obviating the necessity of removing the furnace cover. The total height of the furnace is 28 in. ; depth, back to front, 14 in. ; and width, 16 in. ; diameter of chimney collar, 5 in. Total weight of furnace complete, 130 Ibs. The grate, consisting of nine wrought-iron bars fitted diagonally into a cast-iron frame, can readily be removed or cleaned ; the bars, being of ordinary size and section, can be renewed without difficulty. The cover is of fire-clay, iron bound, with falling handle to economise space in packing. The furnace cannot get out of order, and as all the fittings are removable, they can be duplicated in case of breakage. 14 -CROSS STREET • HATTOT GARDE1ST, E-C 1138 a^ BAIRD &TATLOCK (LONDON) LTD. Cf-f r 6225 225T Furnace, small prospector's Price with chimney and elbow piece 226T Muffles to suit 6227 each £220 £2 15 0 £020 This furnace has been designed to meet in a simple, durable, and portable form all the requirements of the I rospector. It can be used for muffle or crucible work, and accommodates either Battersea muffle C (8 by 4! by 3 in.), l)ur Battersea round crucibles E, three Battersea round crucibles F, two Battersea round crucibles G, or Salamander I'rucible No. 10 (i.e., 20 Ibs. capacity). FOR ASSAYING AND MELTING. The furnace is shown in the illustration fitted for muffle work ; to adapt for crucibles, remove muffle c, and s aperture with clay stopper D. The total height of the furnace is 26 in. ; diameter, loj in. ; diameter of chimney collar, 5 in. ; total weight pmplete, 43 Ibs. 17 Fletcher's Muffle Furnaces for Gas, perfected series, requiring no air blast, the muffles have no " cold mouth," and the whole length can be utilised for most exact work. 8J in. wide. 5i ,. high. 14 „ deep. £9 15 0 20 20 in. wide. 6 „ high. 30 „ deep. £35 0 0 (See Nos. 2824-2971 for other patterns of Gas Furnaces.) Size No. 2 4 6 Clear working space I inside muffle 2 2 4 31 3 6* 51 4* 9 Price £3 17 6 £4 15 0 £6 5 0 Size No. 10 12 18 Clear working space I inside muffle 10 5i 14 12 6 14 18 6 24 Price £11 0 0 £12 0 0 £27 0 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS, fl 113Q \Z7K7 x BAIRD &. WLOCK (LONDON) LTD. 6228 6228s Fletcher's Muffle Furnaces for use with ordinary petroleum. Size No. .... 4 6 8 10 3l 5l 81 I0 3 4t 51 5l 6J 9 14 14 Price £950 £11 0 0 £21 0 0 £23 0 0 Clear working space inside muffle 12 12 in. wide. 6 ., high. 14 „ deep. £24 10 0 Showing Furnace in position for use. See Fig. 6229. CROSS STREET • HATTOTST GARDETST, E- C 1140 BAIRD &TATLOCK (LONDON) LTD. 6229 229s New Prospector's Set. Total weight as engraved, 30 Ibs. Price complete Particulars of Parts for Renewals, etc. No. i. Furnace body .. 2. „ stand » 3- „ lid . . ... 4. Automatic oil burner including — Burner cover and coil Pressure gauge Pump Filter -. Outlet valve £700 £1 16 0 £3 15 0 No. 4A. Burner cover extra i £0 3 0 ,, 4B. „ coil • • i £0 7 6 ,, 5. Spare oil tank, capacity 2 gallons 3 £0 10 1 ,, 6. Two adapters for crucible furnace i £0 1 6 „ 7. Muffle door, lower ) ,,8. „ „ top •- „ 9. Top plug for lid ) ,, 10. Five crucibles, capacity 6 oz. each i each £0 0 2 ,, ii. Five muffles, size 2 in. wide, 2 in. high, 4 in. deep 2j £0 1 t, ,, 12. Pair bow tongs .. £0 1 0 „ 13. „ crucible tongs i £0 /£ 1 ^v () B» y — — "*»— (5 — — ai-^F- «- MJif. • CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- fll W , *A -1\ /t-^V 1141 BAIRD &. TATLOCK (LONDON) LTD. 6230 6231-6232 6233 6230 Gold Washing Pans or Batea, of mahogany, 17 in. diameter, by i| in. deep in centre £0 13 6 6231 Gold Washing Pan, sheet iron, " Australian " pattern, stamped with seamless moulding round flange, and trench in bottom to collect the gold, 15! in. diameter each, 1/4; per doz. £0 15 0 6232 Ditto, 17! in. diameter .. .. .. .. .. ,,1/8; „ £0 19 0 6233 Gold Washing Pan, sheet iron " American " pattern, plain. i6| in. diameter at top each, 1/3; per doz. £0 14 0 6234-6237 6238 6234 Gold Washing Pans, " Miner's Horns " of vulcanite . . each, 3/- ; per doz. £1 15 6235 Gold Washing Pans, " Miner's Horns " of horn unpolished . . ,,1/9 „ £0 19 6236 Gold Washing Pans, " Miner's Horns " of buffalo horn, highly polished each, 2/6; „ £1 8 6237 Gold Washing Pans, " Miner's Horns " of copper, same shape as above, for washing with mercurv .. .. .. .. each £0 3 6238 Gold Dust Blowers, polished sheet brass, for blowing black sand from gold dust. Size • • • • • 4| by 6 6J by 9 in. 3/6 4/6 each. 6239 6240 6239 Hammers, steel, geological, wedge shape both ends, handled. Head 3 by i 4 by ij 6 by ij in. Price 2/3 2/6 4/6 each. 6240 Hammers, for flattening buttons, etc..' one rounded and one flat surface" polished bright, handled. Head • • • • 3 by ij 4i by if in. Pnce .. .. 2/6 3/6 each. 14 -CROSS STREET • HATTC^ST GARDEKT, E-C 1142 BAIRD &TATLOCK (LOM)ON) LTD. 6242 6243 6241 Hammer, some form as-No. 6240, with head weighing 5 Ibs. . . 6242 Hammers, flat one end, pointed the other, handled. Head .. .. .. 3 Price .... 1/9 6243 Hammer or Pounder 6244 Hammers, small, all 'steel, for small buttons 6245 6245s Indiarubber Sheeting, white, single faced, for mixing pulp. No. i quality No. 2 quality 6246s Indiarubber Squares, for cleaning amalgam plates. Size . . . . . . . . 6 by 4 by Price .. .. '.-. .. 8/- 36 61- 4/3 6247 6248 6247s Indiarubber Gloves, short 6248s Indiarubber Gloves, with gauntlets 6249s Indiarubber Mittens, with gauntlets Indiarubber Corks. (See pages Nos. 446-449.) 6244 £0 7 6 4 in. long. 2/3 each. £0 10 6 each £020 6246 54 in. wide. 10/- per yard. 6/6 6 by 6 by \ in. 10/6' each. 6249 per pair ' £0 10 0 £0 13 6 £0 10 6 i: 6250 6250s Ivory Scale, for measuring buttons, to take the place of a balance . . £0 12 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &.WLOCK (LONDON) LTD. 6251 6252 6251 Lenses, horn mounts, single Price 6252 Lenses, horn (doublet magnifiers), best quality Price 6253 Lenses, horn (triplet magnifiers), best quality Price 6254 Lenses (Coddington magnifiers), German silver mounts, shell frame Price 6255 6256 6257 6255 Magnets, horseshoe, with keeper, best English make. Length .. 2\ 3 4 5 6 9 10 Price 3d. 4d. 8d. 1/2 1/6 3/6 5/- 6256s Horseshoe Magnets, 8 by i by i in., with adiustable pole pieces for ore separation 6257 Mallets, beech, morticed . . . . . . . . . . 5 Price .. .. .. .. .. ' .. 1/6 6253 6254 i i if 2 in. 1/4 1/9 2/3 3/- each. f i iA if in. 2/1 2/6 3/- 5/- each. 1 f i if in. 3/- 3/3 3/6 4/6 each. ts, shell frame 1 | in. . • 5/- 6/9 each. 12 in. 7/- each. £0 12 7 in. 3/- each. 6258 6258s Holloway's Mercury Assay Apparatus, porcelain crucible, silver sheet, and copper cooling chamber with inlet and outlet tubes ._. I . . . . . . each £0 5 14-CR.O&S STREET • HATTON GARDEN, E-C 1144 6259 , 6260 6261 MERCURY OR AMALGAM VESSELS OF ENAMELLED CAST-IRON. 6259 Buckets, with strong stop bail handle and bow handle at side ior tilting. Diameter at top Depth inside Price 6260 Cups, Ladling, with cast handle. Capacity Price 6261 Funnels, or Tundish. Diameter Capacity Price 6 51 3/6 4 I 8 8 4/6 * 1/4 6 2 2/4 10 9i 6/6 i 1/8 8 34 a/- 12 in. "i „ 9/- each. i£ pints. 2/- each. 10 in. — pints. 4/- each. 6262 6263 6262 Jugs, Ladling, with cast handle. Capacity Price . . . . . . • . . '6263 Ladles, lipped, with round socket handle. Diameter Price 6264 Pans, deep form, with circular bow handles. Diameter inside . . 8 9 Depth inside . . 4f 4f Price .. .. 4/- 4/3 6264 2 4 6 8 pints. 2/6 3/6 4/6 6/- each. 4 5 6 in. 2/6 a/- 3/6 each. 10 ii 12 15 18 in. 5 si 6 6| 8 „ 4/9 51- 5/6 8/6 14/- each. CHEMICAL'AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1145 BAIRD &TATLOCK (LONDON) LTD. 6265 6266 6265 Mills, flattening, best cast steel rolls, accurately turned. The rolls are of solid steel, case hardened and lapped perfectly true. They can be taken out and replaced •in a few minutes without taking off any wheels. This is an advantage for customers abroad who cannot get mechanics' assistance. Size No. i, length of roll 2 in., diameter of roll ii- in. „ No. 2, „ „ 3 in. „ „ 2 in. „ No. 3, „ „ 4 in. „ „ 2j in. If supplied without stands, 15/- less. 6266 Mills, flattening, best cast steel rolls, accurately turned. The rolls are of solid steel, case hardened and lapped perfectly true. They can be taken out and replaced in a few minutes without taking off any wheels. This is an advantage for customers abroad who cannot get mechanics' .assistance. These rolls are fitted with simultaneous top motion, machine-cut wheels for equal pressure. Size No. i, length of roll 2 in., diameter of roll ii in. „ No. 2, „ „ 3 in. „ 2 in. ,. No. 3, „ „ 4 in. „ „ 2J in. If supplied without stand, 15/- less. £7 15 0 £900 £6 15 0 £9 10 0 £12 10 0 CROSS STREET • HATTCTNr GARDEN, E-C 1146 BAIRD &TATLOCK. (LOM)ON) LTD. 6267 6269 6267 Flattening Mill with multiplying power, on stand .. .. .. .. til 15 0 The rolls are of solid cast steel, 3J in. long by 2j in. diameter, hardened and lapped perfectly true. They can be taken out and replaced in a few minutes without taking off any wheels. This is an advantage for customers abroad, who cannot get mechanics' assistance. 6268 Flattening Mill, as above, fitted with simultaneous top-motion machine cut wheels, for equal pressure, on stand as in Fig. No. 6266 .. .. .. .. .. £13 15 0 6269 Mill, Flattening . . . . . . . . . . . . . . . . £16 10 0 The roll frame is of an improved combined type, and so designed that rolls can be changed easily in two minutes without taking off any wheels. Rolls are of solid cast steel, hardened, ground and lapped perfectly true. Dimensions of rolls 4 in. long by 2j in. diameter. The simultaneous equal pressure motion is fitted with best hardened steel pins and machine-cut steel wheels. The box stand is a new design with door, and is fitted with shelves, to be used as cupboard to keep extra rolls, tools, and accessories. The mill is supplied with two handles. fjCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1147 BAIRD &TATLOCK (LONDON) LTD. 6270 Sturtevant Laboratory 6270 Roll Jaw " Crusher, 6 by 2 in. 6270 (Open for cleaning These machines are superior in design to the majority of. machines on the market, and are well constructed and easily accessible ; weight being 700 Ibs. , the] crusher is specially adapted for hard work, and will withstand severe crushing stresses. The jaws advance and recede very slightly at the discharge, and in addition give the material a rolling movement which assists the crushing action and also prevents the possibility of clogging unless the material is really sticky. They may be set at J in., and the product must be crushed to all below f, in. before it can pass through. They are also easily adjustable for coarser work. 6271 6271 (Open for cleaning) 6271 Sturtevant Laboratory Roll, designed specially for sampling purposes, size 8 by 5 in. This small roll is intended to take ore from the Laboratory Roll Jaw Crusher and reduce to fine sand rapidly and economically. It requires very little power to drive and will run smoothly on any bench or floor. It is designed to meet the special requirements of assay work and carries rolls 8 in. by 5 in., weight complete, 650 Ibs., runs at 150 revolutions, pulleys 18 in. by 4 in., total space required 28 in. wide by 31 in. long by 22 in. high. This small machine can be regulated for coarse or fine work, has adjustable spring pressures which allow a great variety of output. The cover opens as shown in illustration, and carries the side plates and hopper. Every part is exposed and immediately accessible for cleaning or replacing. It can do fine or coarse work, and is capable of taking and crushing hard rock from the Laboratory Roll Jaw Crusher down to 60 mesh. It is practically dust-proof, is fitted with special axle-box bearings and is in all respects as carefully constructed as the larger machines on the market. £36 5 0 14 • CROSS STREET • HATTCTN GARDEN, E 1148 BAIRD &TATLOCK: (LONDON) LTD. 6272 6272 (Open for cleaning). 6272 Sturtevant Laboratory Grinder . . . . . . . . . . . . £24 15 This is adapted for grinding ore taken from laboratory roll, or from mortar, reducing it at once to practically any degree of fineness for perfect sampling and correct assaying. The grinding is done between manganese steel or built-up corundum discs, easily and cheaply replaced ; the i output being regulated by the hand-wheel to deliver a coarse or fine product as desired. The grinder weighs about 175 Ibs., requires about 3 H.P. to run to full capacity, speed 750 to 800 R.P.M. I Pulley 7 in. diameter by 3! in. Dimensions — length 27 in., width 15 in., height 16 in. When these machines were first used on coarse and very cutting ores, the grinding plates would score or ring, after which the output became uneven in character and reduced in quantity, and this long before the grinding 1 plates were worn out. This has been remedied by arranging the stationary disc or grinding plate so that it can be moved frequently from its centre, thus changing the relative positions of the two grinding surfaces, so that all cuts, scores, or rings [made in the faces may grind themselves out. Fine and even grinding is thus assured. We would call special attention to the ease and rapidity with which these machines can be cleaned. The door I latch is raised and the door swung open. Not even a bolt is removed to give full access to the interior. i 6273 i273T Sturtevant Laboratory Screen This screen has been designed lor laboratory use and may be run either by hand or power. Every part is iccessible for quick and thorough cleaning. It can be set upon any suitable bench or on the floor, and has a capacity of from 100 to 1,000 Ibs. per hour ; it is as nearly dust-proof as any device of its class. Weight, net, 55 Ibs., width 21 in , length 42 in. .height 27 in., pulley i8in. by ijin. £22 10 0 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1149 BAIRD &TATLOCK. (LONDON) LTD. 6274 6275 6274 Miner's Vanning Shovel A6274 Miner's Vanning Shovel, aluminium 6275 Miner's Prospecting Pick, weight of head ij lb., length of handle, 18 in. 6276s 6277s 6278s 6279s 6280s 6281s 6282s 6283s 6284s 6285s 6286s 6276-6286 MINERALS IN SETS. Elementary Collections (in Cabinets) arranged to illustrate Dana's 50 Specimens, small, but all characteristic, with name and locality 100 Specimens, small, but all characteristic, with name and locality 200 Specimens, small, but all characteristic, with name and locality The same number of larger specimens at proportionate prices. Arranged to illustrate Rutley's " Text-Book of Mineralogy." 50 Specimens, in cabinet 100 Specimens, in cabinet 200 Specimens, in cabinet 300 Specimens, in cabinet COLLECTIONS OF METALLIC ORES. Collection of 100 ores of metals, i^ by I in. Collection of 100 ores of metals, 2 by 2 in. Collection of 200 ores of metals, ii by i in. Collection of 200 ores of metals, 2 by 2 in. Larger Collections and larger Specimens to any price. Mineralogy. £0 10 6 £1 £3 1 3 0 0 £6 6 0 £2 2 0 £3 3 0 £5 5 0 £7 7 0 1150 BAIR.D &TATLOCK (LONDON) LTD. MINERAL CRYSTALS. 6287s 6288s 6289s 6290s 6291s 6292s 6293s 6294s 6295s 25 Natural crystals of minerals 50 Natural crystals of minerals 25 Fragments of minerals for blowpipe experiment . . 50 Fragments of minerals for blowpipe experiment . . 104 Larger fragments of minerals for blowpipe experiment 40 Larger fragments for use with Ross' " Pyrology " 80 Larger fragments for use with Ross' " Pyrology " Moh's scale of mineral hardness Von Kobell's scale of fusibility of minerals . . £1 1 0 £2 10 0 £026 £050 £0 18 0 £060 £0 12 6 £050 £030 6296 6297 6296s Explorer's Mineral Cabinet of minerals, precious stones, etc. Packed in a small, compact, portable, mahogany, well-made cabinet of 6 drawers, containing examples of 30 varieties of precious stones as found in a native state ; 20 specimens of the typical rocks, such as metals and minerals would be found in or associated with ; and 200 specimens of ores of metals and useful minerals, such as are valuable for commercial purposes, all with names and localities. All are numbered corresponding to names on labels, etc., so that no difficulty can arise from confusion. The 200 minerals and ores are intended for comparison with specimens that may be found by travellers. Of some species more than one specimen is given, showing different characters, etc. Price 6297 Mortar, amalgam, Buck's pattern, for grinding and amalgamating. By the rotation of the muller a large sample of ore can be ground in contact with quicksilver. Diameter 6i in., total weight 30 Ibs., weight of muller 16 Ibs. £12 12 0 £1 10 0 6298 6298 6298 Mortars, for quartz, turned inside, with pestles with long wooden handles well fixed. Diameter .. .-5 5l 6 6£ 7 8 in. Price . . . . 12/6 14/- 16/- 19/- 22/- 29/- each nCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- f _4\ fL W i _ *A .--**. /zri 11:1 ^ j^xav, 'BAIRD &TATLOCK (LONDON) LTD. £0 6299 6300 6301 6302 6299 Mortars, iron, flat bottom, 4J in. diameter by 2§ in. deep inside, with pestle . . 6300 Moulds, oblong, iron, for casting ingots. No ...... i Size • • • • 4s by i| by i 5 is by 2 by T"ff in. Price 4/' 5/~ ?er doz- 6301 Moulds, bar, iron, for casting ingots. Si?e 3 by* by | 3i by2| by I 3f by i by I 4 by i* by i 4|by i|by ij in. Price 6d. 8d. I/- I/- 1/9 each. No .... 6 7 Size . . 6 by ij by ij 7! by if by 2 8| by 2* by 2§ in. Price 2/6 3/- 5/6 each. 6302 Moulds, bar, with two spaces, each 4 by 2-| by aj in. 6303 6304 6303 Moulds, button, two half-round holes, turned inside, with wood handle 6304 Moulds, button, two conical holes, turned inside, with wood handle . . 6305 Moulds, button, four half-round holes, turned inside, with wood handles £0 10 0 6306-6309 6306 Moulds, 6307 Moulds, 6308 Moulds, 6309 Moulds, 6310 Moulds, 6311 Moulds, 6312 Moulds, 6313 Moulds, 6310-6311 6312 iron, ingot, not turned inside, 3 in. deep ; width across top, 3^ in. iron, ingot, not turned inside, 3^ in. deep ; width across top, 4^ in. iron, ingot, turned inside, 3! in. deep ; width across top, 3^ in. iron, ingot, turned inside, 3^ in. deep ; width across top, 4! in. iron, ingot, double form iron, ingot, double form, turned inside iron, ingot, with three receptacles, turned inside iron, black inside, with cast handle. 6 9 12 cavities. 3/6 4/- 5/- each. each CROSS STREET • HATTCHNT GARDEN, E- C BAIRD &TATLOCK (LONDON) LTD. 6314A 6314B •6314s Muffles, fire-clay, with or without apertures (A or B) Size AY AX AZ A B C D Length 4 Width 2| Height 2 1 Each 9d. 6 3i 7i 41 2| 8 8* 5 I/- 1/2 1/9 21- 2/3 2/6 E 9 3i F 10 6 4 G ii 4 3i 6315 H 5J Muffle, pure nickel, 140 by 80 by 65 millimetres 3/6 2/6 3/3 J 12 6 4 14 8 each L 15 in. 9 .. 6 „ 6/6 £0 15 6 <63163 6316 Iron Moulds for .casting rods of metal 100 by 7 millimetres diameter, with clamp. To cast . . . . . . . . 6 i? 18 rods. Each .. .. .. .. is/_ lh/- 30/- 6317 6318 -6317 6318 Pliers, steel, with cutting edge, square noses, length 5 in. Pliers, steel, with cutting edge, half-round noses, length 5 in. •6319 Pliers, with fine straight noses for holding buttons, length 4 in. •6320 Pliers ox Cutting Nippers, 6 in. . . 6319 each, 1/6 ; per doz. , 1/8 ; ., each 6320 £0 17 0 £0 19 0 £0 1 3 £01 3 1153 BAIRD &TATLOCK (LONDON) LTD. 6321 6321 Electro-Magnetic Ore Separator, with 6-in. horseshoe electro-magnet, fitted with brass bobbins and wound with copper wire 16 B.W.G., two special pole pieces fitted and slotted to allow adjustment of gap. The electro-magnet is suspended from a bracket on hardwood stand, the back of which is secured by two pinching screws, with the following accessories : — Dynamo, 10 volts 3 amps., 3,000 R.P.M. ; hand-driving gear for above, piece copper gauze, 6 yards copper wire, i pocket ammeter to 5 amps., with cases for magnet and dynamo £8 15 0 6323 6324 6322 Poker, iron, for furnaces, 3 ft. long Punches, well tempered, strong cast steel, for stamping bullion. A i TS 1 6323 Set of figures, o to 9 . . 4/- 4/- 5/- 5/6 6324 Set of alphabet, A to Z . . 12/- 12/- 13/- 14/- 6325 Punches, made to order, best extra strong steel, over three letters. i I re i A Per letter .. 9d. 8d. 7d. 6d. 5d. 6326 Paper, glazed, for mixing pulverised ore, white, black, or red 6322 6325 5 TF 7/6 16/- i 5d. 8/6 £0 | in. 12/- per set. 33/- A 5d. 5d. per quire, 1/3 ; per ream £1 00 CROSS STREET • HATTCTST GARDETST, E-C BAIRD &TATLOCK (LONDON) LTD. 6327 BOASTING DISH 6329 6327 Parting Flask Heating Stand, with spirit lamps, sand trays of copper. For Price 6328 Parting Flask Stand, teak- wood, for six flasks 6329 Roasting Dishes. Diameter Price 1/8 19/- 2 25/- 3 a/- 22/- 6328 4 6 flasks. 30/- 38/- each. each £0 5 6 4 5 in. 2/6 2/9 per doz. 27/6 33/6 per gross. 6330 6332-3 6330 Sample Wood Boxes, with sliding lids, for holding samples of ore. Length if 2| 3$ Width . . . . . . . . ij 2 2j Depth . . . . . . . . i£ 2 Price .. .. .. I/- 1/6 2/3 .... 10/6 171- 24/- 6331 Sample Boxes, round tin, with lids, for holding small samples of powdered ore. 2* „ 3/9 per doz. 39 /- per gross. 2 by | 2f by 71- . 91- 6332 Sampling Troughs of tin plate, for sampling ground ores. 9 by 6 in. — 6 troughs. 9 by 12 in. — 5 troughs. 4/6 51- 6333 Sampling Shovels for use with above. Size . . . . . . . . 9 by 7 Price .. .. .. .. 2/6 2\ by i II/- per gross. 10 by 10 in. — 6 troughs. 6/- each. 12 by 9 31- 12 by 12 3/6 each. 6334 6334 Sampler, steel, with handle Length Price 18 31- 24 in. 5/- each. 1CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1155 BAIRD &TXTLOCK (LONDON) LTD. 6335 6336 6335 Scoops, amalgam, of Russian iron, for scraping amalgam from plates. Size . . . . . . . . . . . . 4 by 3^ 4 by 6 in. Price .. .. .. .. .. 1/6 2/3 each. 6336 Scoop or Crucible Filler, for pouring fluxes or ore into crucibles while in the furnace, 17 by 3 in. . . . . . . . . . . . . • • • • £036 6337 6337 Scoops, copper, with handle. Length Price 6338 Scoops, vulcanite. Size Price 6339 Scoops, horn. Length Price 6338 6339 .... 5 6 8 10 12 in. .. 3/6 4/- 4/6 5/6 7/- each. 3t by 2j 4f by 2| in. 9d. 1/6 each. 8/6 15/- per doz. 2f 3| 4l 6 in. 4d. 5d. 6d. 8d. each. 3/" 5/6 -ft 7/6 per doz. 6341 6342 6340 Scraper, chisel end, 3^ ft. long 6341 Scraper, hoe end, 3^ ft. long 6342 Shovel, iron, for furnace . . 6343 Scoriflers, clay. Diameter i ij Price 4/6 5/6 ii ' 2 6/6 6/6 7/6 2| 6344-5 6344 Scrapers, muffle, flat, 36 in. long . . 6345 Scrapers, muffle, bent end, 36 in. long BATTERSEA SCORIFIER 6343 £026 £026 £03 3 3* 4 in. 10/6 13/6 15/- per gross. each £026 £026 1156 BAIRD &TATLOCK (LONDON) LTD. 6346 ji346 Seals, lead, for sealing samples of ore in bags 6347 6349 8 m. 12/- per 1,000. 6348 $47 Sealers or Pliers, for use in clamping above . . £ Price . . . . . . . . . . 16/- 548 Shears for cutting metal. Length . . . . . . 6 7 8 Price ... .. .. 1/6 1/8 21- 149 Shears, heavy pattern, for clamping in bench vice, weight about 12 Ibs. 9 2/6 I in- 22/6 each. 10 in. 31- each. £0 18 0 6350 650 Sieves, wood rims, 3^ in. deep, brass wire gauze. Diameter . . . . . . . . 12 16 18 24 in. 10 mesh . . . . . . . . 1\- 3/4 4/3 7/6 each. 20 ,, .. .. .. 11- 3/6 4/6 8/- 30 „ 2/3 4/- 5/- 8/3 „ 40 „ .. .. 2/4 4/3 5/6 8/6 „ 60 „ .. .. .. .. 3,1- 4/6 6/- 9/6 ,. 80 ,. .. .. .. .. 3/3 51- 6/6 10/6 .. 100 . . . . . . . . 4/6 7/6 8/- 14/- .. 120 „ .. .. .. 51- =r<\ 91- 15/- „ / CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TXTLOCK. (LOM)ON)LTD. 4 6 8 9 in. 1/1 1/3 1/6 1/9 each. 1/1 1/3 1/6 1/9 „ 1/1 1/3 1/6 1/9 „ 1/2 1/4 1/7 1/10 „ 1/3 1/6 1/9 2/- „ 1/4 1/8 2/- 2/3 „ 1/6 1/10 2/3 2/6 „ 1/9 2/- 2/6 3/- „ 21- 2/6 3/- 3/6 „ 2/6 3/- 3/6 4/- „ l/- 1/3 1/6 1/8 „ 6d. 8d. lOd. I/' M by the Institution of Mining and 6351 6354 6351 Sieves, brass wire gauze, with japanned tin frame. Diameter 10 mesh 20 30 ., 40 „ 60 „ 80 „ 90 ,. IOO 120 ,, 150 „ 6352 Lid to suit 6353 Bottom to suit . . 6354T Standard Laboratory Sieves, as recommended Metallurgy, brass rims, diameter 8 in. Mesh 5, 8, 10, 12, 16, 20, 30, 40 „ 50, 60, 70, 80, 90 ,, 100, 120, 150, 200 63551 Brass Cover and Receiver for above 63561 Wire Weaving for above in 8 in. squares without rims. Mesh, 5, 8, 10, 12, 16, 20, 30, 40 „ 50, 60, 70, 80, 90 ,, 100, 120, 150, 200 Extract from pamphlet issued by the Institution of Mining and Metallurgy and from the official makers' pamphlet. STANDARDISATION. MESH OF WIRE CLOTH. The following table of " I.M.M. Standard Laboratory Screens " is intended for use in making grading tests and for the correlation of screens used in commercial or other work. When screens other than the I.M.M. Standards are employed, the diameters of apertures should be given in any published results, so that comparisons may be made. When screens are described simply by the number of meshes per linear inch, it will be understood that the I M.M. Standard is referred to. each tt £1 £1 £1 1 2 4 : per set £0 9 • each » £0 £0 £0 6 7 9 0 6 0 -CROSS STREET • HATTCTN GARDEN, E-C 1158 BAIRD &TATLOCK (LONDON) LTD. C-p L The number of sizes standarised has been reduced to a minimum, as it is desirable to abandon excessive refinements in gradiag tests. It is believed that the I.M.M. Standards will meet all necessary requirements of the laboratory. In reporting grading tests it is desirable to state whether wet or dry screening has been employed. TABLE. I.M.M. Standard Laboratory Screens. Diameter of WIRE. APERTURE. Screening MESH Area. or apertures per linear Inch. in. mm. in. mm. Per cent. 5 O.I 2.540 O.I 2.540 25.00 8 0.063 1. 000 0.062 1-574 ' 24.60 10 0.05 1.270 0.05 1.270 25.00 12 0.0417 1.059 0.0416 1.056 24.92 16 0.0313 0-795 0.0312 0.792 24.92 20 0.025 0.635 0.025 0.635 25.00 3° 0.0167 0.424 0.0166 0.421 24.80 40 0.0125 0-3I7 0.0125 0.317 25.00 50 O.OI 0.254 O.OI 0.254 25.00 60 0.0083 0.2II 0.0083 . O.2II 24.80 70 0.0071 O.lSo 0.0071 0.180 24.70 80 0.0063 0.100 0.0062 0-157 24.60 90 0.0055 0.139 0.0055 0.139 24.50 TOO 0.005 0.127 0.005 0.127 25.00 120 0.0041 0.104 0.0042 0.107 25.40 150 0.0033 0.084 0.0033 0.084 24.50 2OO 0.0025 0.063 0.0025 0.063 25.00 NOTE. — Whilst absolute accuracy to the fourth place of decimals of an inch is impracticable in the manu- j facture of Wire Cloth, a sufficiently close approximation to the above standards is attainable. The adoption of a screening area of 25%, necessitating equality of size of wire and aperture, secures perfect I interlocking and consequent permanence of aperture. Some of the finer mesh screens can only be woven in what is known as " twilled." 6357 6358 6357 Skimmer for Crucibles, round, iron, 36 by J in. 6358 Skimmer for Crucibles, 36 in. long, perforated bowl 559 Spoon for Sampling Melted Bullion, 4 ft. long, bowl i in. A 11 C Stencil Plates, alphabet. Size 6360 Zinc, per set 6361 Brass, per set Stencil Plates, figures. Size :362 Zinc, per set 363 Brass, per set 6360-6363 i 2/3 i I/- 1/3 £036 £050 £060 I* 3/6 4/9 1/6 1/9 2 in. 4/6 61- 2 in. 1/9 2/3 1159 BAIRD &L TATLOCK (LONDON) LTD. 6364 6364 6/6 i 71- 6364s Stencils, " Interchangeable Lock." A set contains two each of all letters, with exception of X, Y, and Z ; one each figure from i to 9, two figures o ; ten pieces of blank, full stops, etc. ; total seventy pieces. Each set in box. Size . . . . . . . . i Price .. .. .. .. 6/- 6365 Stencil Brushes. No. i No. 2 6366 Stencil Inks, black, blue, or red. Black. Price 9d. 2 in. 15/- per set. each Red. H- Blue. II- per cake. 6367 6367 Turning Out Rack, of teak, for conical parting flasks 6368 Test Needles, of gold. Nine needles fastened'to a ring, numbered, and containing gold upon their points of 4, 6, 8, 10, 12, 14, 16, 18, and 20 carats fine . . . . per set 6368 £0 15 6369 6369 Tongs, for furnaces, with bow. Length Price 6370 Tongs, for furnaces, with bend and bow. Length Price 6370 21- M 2/9 18 2/3 18 24 in. 2/6 each. 24 in. 3/3 each. 14 • CROSS STREET • HATTQTNT GARDEN, E- C 1160 BAIRD ^TATLOCK (LONDON) LTD. 6371 6371 Tongs, for furnaces, basket form. Length Price 6372 Tongs, for furnaces, straight. Length Price 24 14 1/6 6373 6373 Tongs, for furnaces, " Charcoal tongs. Length Price 6374 Tongs, for furnaces, with hend. Length Price 6375 6375 Tongs, for lifting cupels. Length Price 6376 Tongs, for lifting scorifiers. Length Price 6377 6378 6377 Twine, for tying samples 6378 Vices, hand. Length Price 6379 Vice, to screw to table. Weight Price 6380 Vice, strong parallel. Jaws Opens Weight about Price 14 1/6 14 1/9 24 6379 3 2/6 4 3/- 3 7 10/6 6372 28 71- 18 1/9 32 >n. 8/6 each. 24 in. 2j- each. 6374 16 1/9 18 6376 30 24 18 in. 2/- each. 24 in. 2/3 each. 36 in. 3/- each. 32 in. 3/- each 3i 7/6 3* 4i 20 17/6 6380 .. per ball £007 6 in. 6/- each. 5 Ibs. 9/6 each. 4l in. 5i ,, 46 Ibs. 30/- CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1161 BAIRD &TATLOCK. (LONDON) LTD. 6381 Wire Cloth, Mesh Made of wire 6381 treble, extra strong, steel, for mining purposes. 2 3 4 5 6 7 Mesh .. Made of wire io ii 13 14 X5 J6 1/6 1/6 1/6 1/6 1/6 1/6 18 20 24 26 28 30 23 24 26 27 28 29 8 17 10 18 1/6 1/6 32 34 29 30 6382 Wire Cloth, Mesh Made of Brass Copper 6383 Wire Cloth, Mesh Brass Copper 1/4 1/4 1/4 1/4 1/4 1/4 1/4 1/4 brass or copper, for battery screens, sieves, etc. 4 6 8 io 14 18 20 24 wire 20 22 24 25 27 29 29 30 lOd. lOd. lOd. lOd. lOd. 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/4 1/6 1/6 1/6 brass or copper, best quality, fine mesh. . . 50 60 80 90 100 140 160 ..1/6 1/8 21- 2/3 3/- 4/6 6/- .. 1/8 1/10 2/4 3/- 3/6 6382 12 2O 1/4 1/4 36 38 30 31 1/4 1/8 14 21 30 33 36 34 1/2 1/2 1/6 1/6 180 200 7/6 8/6 SURVEYING AND MINING INSTRUMENTS. 16 22 S.W.G. 1/4 per sq. 40 31 S.W.G. 1/8 per sq.ft. 40 35 S.W.G. 1/3 per sq. ft. 1/8 „ 240 12/- per sq.ft. : 6384 6385 6384s Plane Table, 15 in. by 15 in., white wood, with 12 in. sight rule in leather case, boxwood trough, compass and tripod stand 3 in. 4 in. 6 in. 6385 Spirit Level with brass stand in case .. .. 1/6 2j- 2j- £220 6386 6387-6388 6386 Spirit Level with hardwood sole and brass top . . . . 6 in., lOd. ; 8 in. £010 6387 Spirit Level, 15 centimetres, fitted in case, with graduated level scale for accurate work, on steel base, as shown on levelling table . . . . . . . . . . £076 CROSS STREET • HATTCTNr GARDE1ST, E-C 1162 BAIRD «kT\TLOCK (LOM)ON) LTD. 6388 Levelling Table, glass plate 8 in. diameter, J in. thick, fitted with three brass levelling screws for practice in levelling and for testing spirit levels. Price with glass plate but without level . £096 6389 6389 Spirit Level, circular form, in brass J in., I/- ; li in. £056 6391 6391T Students' Theodolite 6392 £220 . 6392T Theodolites, best, divided on silver, with parallel plates and tripod stand, complete in mahogany case. 4 5 5 6 6 in. Divided to i min. i min. 20 sec. 20 sec. 10 sec. £21 10 0 £24 0 0 £25 10 0 £27 10 0 £30 0 0 1 6393' Transit Bell Theodolites, divided on silver, with parallel plates, and tripod stand, complete in mahogany case 4 5 5 6 6 in. Divided to i min. i min. 20 sec. 20 sec. 10 sec. £24 0 0 £26 10 0 6394T Diagonal Eyepiece for above instruments . . 6395T Open Frame Tripod for above instruments 6396T Centring Head, for above instruments 6397' Hoffman Head for above instruments 2O sec. £27 10 0 20 sec. £30 10 0 £32 0 extra 0 £1 1 £0 18 £1 10 £2 2 jfJCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &. TATLOCK (LONDON) LTD. 6398 Gravatt's or .Dumpy Levels, light construction, complete in case. 8 10 12 6398T Without Compass .. £550 £10 10 0 £11 0 0 6399T With Compass £660 10 £11 10 0 12 £12 10 0 14 in. £13 10 0 14 in. £15 0 0 6400 6404 extra 6400T Improved Y Levels, with parallel plates and tripod stand, with compass in case. 10 12 15 18 in. £13 10 0 £14 15 0 £18 0 0 £21 10 0 640 1T Improved Locking for above Levels 6402T Hoffmann Head, with tangent adjustment for above levels . . 6403T Sliding Leg Tripods for above levels • 6404T Miner's Dial, 4 in. plain, in case, with jointed legs . . 6405T Miner's Dial, 5 in. plain, jointed sights, divided on cover for hypotenuse and base, with ball and socket, in case, jointed legs £1 16 £220 £0 18 0 £600 £7 15 0 CROSS STREET • HATTCXN GARDEN, E-C 1164 BAIRD &TATLOCK (LONDON) LTD. 6406-6410 6411-6412 64067 Prismatic Compass, 2 in., card dial, jewelled centre, morocco case . . ..£113 64071 Prismatic Compass, z\ in., „ ,, sling leather case .. .. £20 64081 Prismatic Compass, 3 in., ,, .. ,, . . . . £26 6409' Prismatic Compass, 3i in., ,, ,, ,, .... £2 9 6410T Prismatic Compass, 4 in., ,, ,, ,, .... £2 13 641 11 Prismatic Compass, 3 in., Hutchinson's form, opening in cover, slight leather case .. £24 6412r Prismatic Compass, 4 in., ,, ,, ,, ,, ,, ., .. £2 11 6413T Engine divided Aluminium Rings for compasses Nos. 6406 to 6412 . . . . extra £0 15 6414r Tripod Stands, ball and socket, for compasses Nos. 6406 to 6412 . . ,, £1 12 0 0 0 0 0 0 0 0 0 6416 \YheninuseasClinometer. , 6415 6416 When in use as Sight Compass. 6415' Prismatic Compass, 3 in., and altitude combined, in sling case . . . . . . £3 16 0 6416T Clinometer Compass, 2i in., silvered dial, edge bar needle, sight in base, metal case . . £0 19 0 6417T Clinometer Compass, 3 in., .. £130 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1165 BAIRD & TATLOCK (LONDON) LTD. 6418 6420 6418T Compass, 5 in., Lean's dial, with telescope and rack, semi-circle and telescope to remove for use, with sights only, in case, jointed legs in separate case 6419T Compass, 6 in., Lean's dial, with telescope and rack, semi-circle and telescope to remove for use, with sights only, in case, jointed legs in separate case 6420T Compass, 5 in., improved Medley dial, rocking centre, outside vernier, improved arc, telescope and sights interchangeable, with Hoffman head . . 6421T Compass, 6 in., improved Hedley dial, rocking centre, outside vernier, improved arc, telescope and sights interchangeable, with Hoffman head 6422 6423-6424 6422T Pocket Sextant, best make, divided on silver, morocco case, with telescope . . 6423T Pocket Clinometer, boxwood, one level, compass, no sights, in case . . 6424T Pocket Clinometer, boxwood, two levels, compass, two sights £6 15 0 £150 £1 16 0 6425T 6426* 6425 Locke's Pocket Reflecting Level, metal case, 5 in. long, in leather case Locke's Pocket Reflecting Level, nickel-plated . . £0 18 £1 0 14 • CROSS STREET- HATTCW GARDEN, E-C 1166 BAIRD &TXTLOCK. (LONDON) LTD. M 6427 6427T Pocket Clinometer, boxwood, two levels, flush vernier, with swing compass, jewelled centre and stop, in case £2 10 0 6428 6429-6431 6428r Pocket Compass, 2 in. bronzed spring hunter case; metal dial, raised graduated ring, bar needle ; agate cap and stop . . . . . . . . . . . . ..£0106 64291 Cross Staff Heads, octagon, with staff socket, 2\ in. diameter . . . . . . £080 64301 Cross Staff Heads, octagon, with staff socket, ai in. diameter . . . . . . £096 6431T Cross Staff Heads, octagon, with staff socket, 3 in. diameter .. .. .. £0 10 6 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS, f v. W J\ At— BAIRD & IATLOCK (LONDON) LTD. 6432 6432' Abney's Pocket Reflecting Level, with graduated arc, 5 in. long, with draw telescope and improved central fixing clamp to vernier, for the measurement of vertical angles, in leather case £1 17 6433 64331 Improved Abney Level, comprising the addition of a magnetic compass on upper side of tube, and on the lower side a circular base upon which the whole rotates, and horizontal angles can be measured, the vertical angles being measured by the arc in the usual way. Complete in case, with staff socket £2 14 6434 Surveying and Mining Aneroid. Giving readings to single feet of altitude. >tout bronzed metal case, silvered metal dial, vernier scale, moved by rackwork motion. Reading lens arranged to traverse the entire circle. Altitude scale'to 6,000 ft. Com- pensated for temperature. In solid leather sling case, 3 in. diameter Same as above, but 5 in. diameter, giving more open divisions Same as above, but 5 in. diameter, with altitude scale to 10,000 feet . 6435 6436 £5 5 £5 12 £5 17 BAIRD &TATLOCK (LONDON) LTD. THE THEODOLETTE. Patent No. 15472. New Instrument for Land and Mining Surveyors, Civil Engineers, etc Illustrations about two-thirds full size. £880 >7T A surveying instrument of small and compact dimension, capable of fulfilling many requirements, is a great desideratum, and the instrument described below has been invented to facilitate the taking of angular measurements, either horizontally or vertically, with accuracy and despatch hitherto only obtainable with the larger and more_expensive instruments. Complete with leather sling cases The instrument measures 7 in. by 3 in. by ij in., and weighs thirteen ounces. The body contains a clinometer disc and a .pass dial, both of aluminium, divided on the periphery into half degrees, being read through a telescope of strong power, bling the observer to obtain very accurate results. The face of the clinometer disc is divided into degrees, and has a proportion le for determining heights and setting-out levels. The scales are read through a window over the face of the disc. The compass 1 is divided on the face to every five degrees, figured every 20 to 360, and 8 compass letters for use as an ordinary compass, o levels are mounted on a loose collar, rotating on the body of the telescope ; these are for the purpose of levelling the instrument, en in the horizontal (Compass, Fig. i) or vertical (Clinometer, Fig. 2) position. A screwed socket is fitted for attaching the rument to the double action head of a light but rigid aluminium telescopic stand. A foot is also attached, so that the instrument be used for ascertaining or setting out angles of slope on surfaces. When once the instrument is set up, forward or backward lings can be taken by simply turning the instrument end for end. For Finding Heights of Buildings, etc. — The instrument is aligned on the objective, and a note made of the division on the roportion ' ' scale that cuts the index line on glass. The distance from observer's position to base of the objective is now measured the distance divided by the figure noted ; the result, plus height of observer, is the height required. For instance, supposing index line cuts division 3, and the distance is 150 ft., 150-^3 = 50 ft. + height of observer = height of object. The following tables will be found of much assistance. Table A gives certain angles of elevation or depression, which give :y of rise per amount of run. Thus 18 deg. of elevation gives i vertical to 3.0 horizontal. Table B gives certain angles up 5 deg., the amount of rise or fall per 100 of run, measured horizontally. Heights can therefore be found as follows : — Thus, 4 deg. of elevation the rise would be 7.0 per 100 horizontal, and an object 300 ft. from the observer, extending an angle of e. would be 7.0 X 3 = 21 ft. in vertical height. TABLE A. Degrees. One in. Degrees. One in. Degrees. One in. Degrees. One in i 57-° 8 7.1 18 3-o 30 1-73 2 28.6 9 6.3 20 2.7 32 i. 60 3 19.0 10 5-6 22 2.4 34 1-43 4 »4-3 12 4-7 24 2.2 36 '•37 5 11.4 14 4.0 26 2.0 38 1-23 6 9-5 16 3-4 28 1.88 45 I.O 7 §> 8.1 fZ^ SfiA-f—TSZ^X £Sf»*^ — "^ ^y^ CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. TABLE B. Horizontal Horizontal Horizontal Angle. Distance, 100. Rise or Fall. Distance, 100. Angle. Rise or Fall. Distance, 100. Angle. Rise or Fall. I 1.7 12 21.4 35 7°-5 2 3-5 13 23.2 40 84.2 3 5-3 M 25.2 45 IOO.O 4 7.0 15 26.9 50 no 5 8.8 16 . . .. 28.7 55 M3 6 10.6 17 3°-7 60 174 7 11.3 18 3L8 65 214 8 14.1 19 34-5 70 275 9 16.0 20 36.6 75 3°3 10 17.7 25 46.9 80 575 II 19.5 30 58.0 85 1143 64381 64391 6438-6439 ^*^P Full size The Service Pattern Luminous Prismatic Compass, Mark V. and VI. As universally used by officers of the British Army.. An accurate compact and serviceable instrument of best make and finish. Mark VI., complete in solid leather sling or belt case Mark V., complete in solid leather sling or belt case . . „. £2 £2 15 6 6440 6440T The " Simplex " Range-Finder and Surveying Instrument. (Major Baden-Powell's Patent, new pattern Mark II.) This convenient little instrument consists of a short metal tube with one end half closed by reflector, set at an angle of 45 deg. ; and at the other end are two small slits, numbered i and 2. The ring forms a shutter which can be folded over so that only one slit at a time can be looked through. Directions for use sent with each instrument. Engraved scales, 3/9 extra. Leather case for belt, 2/- extra. Price £110 CROSS STREET • HATTCnST GARDETST, E- C 1170 BAIRD &TATLOCK. (LONDON) LTD, 6441 6442 6441T Clinograph. The clinograph is a very useful instrument when a number of lines are required at an angle to the base line other than are found on an ordinary set square. The arc attached to the movable arm is divided to degrees, and a clamping screw tightens to an auxiliary strip of metal, which presses on arc and holds firmly when set. Two working edges are provided so that angles and opposite angles of any degree are accurately obtained. Made in dyed hardwood, with two celluloid edges and German silver arc, engine divided. Price, 6 in., 7/- ; 7 in., 8/- ; gin. . £0 10 6 |6442T Sketching Boards, improved military pattern, polished .. .. .. .. £1156 Working surface of board, Kaurie pine, top and bottom cleats, polished boxwood, fitted with best compass, I with bar needle, on agate centre, and line of direction etched on glass. Lacquered brass rollers, sight screws at [bottom of board, rubber bands, boxwood straight edge, and Clinometer divided on boxwood arc to 60 deg., and [fitted with spring clamp, top cleat divided round compass to ten degrees, and scaled H.E., 20 ft. at 6 in. to M, j 4 in. to M, and 6 in. to M. Bottom cleat divided to inches and tenths, best quality bridle leather, wrist strap with covered brass buckle, vivelled on brass plate, which is let into back of board flush. Size of working surface of board, i\ in. by 5j in. [Rubber bands and boxwood straight edge. 13T Waterproof Canvas Case, best quality, leather bound, for above . . . . . . £046 6444-6446 Land Chains. The 2 and 4 pole chains are divided into links, and tallied at every ten links. The 50 and 100 ft. chains are divided into feet, and tallied at every 10 ft. Made of best iron wire, with three oval rings, brass swivel handles and tallies. 2 4 poles. 50 100 ft. 444T No. 7. W.G. .. .. .. 6/- 10/- 6/9 1 1/- each. •445r No. 8. W.G. .. «446T No. 9. W.G. . . 5/9 5/3 9/6 8/3 6/6 5/9 10/6 9/6 V»iX*k/ 'BAIRD &TATLOCK (LONDON) LTD. 6456 6457 Metre. Divided into fifths of metres, and tallied at every two metres. Made of best iron wire, with two oval rings, brass swivel handles and tallies. 10 20 25 metres. 5/3 8/3 10/6 each. 4/9 6/9 9/6 „ 61- 9/- llf- „ 6447* No. 8. W.G. 6448T No. 9. W.G. 6449T No. 7. W.G. Land Chain Arrows, 15 in. long, in sets of ten. 6450T No. 10, made of best cast steel wire, hardened, tempered, and black enamelled per set £012 645 1T No. 8, made of best cast steel wire, hardened, tempered, and black enamelled ,, £014 6452T No. 7, made of best cast steel wire, hardened, tempered, and black enamelled „ £016 6453T No. 6, made of best cast steel wire, hardened, tempered, and black enamelled ,, £018 6454T No. 7, made of best iron wire . . . . . . . . . . . . „ £010 6455T No. 6, ditto, ditto . . . . . . . . . . . . . . „ £011 Patent Steel Band Measuring Chain, width of band | in., divided into links, and numbered at every ten links. Length 6456T Price in cross as figured . . 6457T Price in metal case as figured 2 poles. £086 £0 12 6 4 poles. £0 13 6 £0 17 6 CROSS STREET • HATTCVN GARDEK, E-C 1172 BAIRD &. WLOCK (LONDON) LTD. Scientific Books 173^1186 Any books not found in the following list we shall b< pleased to obtain at published prices. Section XXV. Chemicals Index 1187-1246 1247 &TXTLOCK (LONDON) LTD. The following are the different Sections in our Catalogue. Those marked * are also printed separately. Pages Nos. Section No. 1." Laboratory Fittings 14-56 2.* Bacteriological Apparatus 57-161 3. Chemical Physiology Apparatus 162-192 4.* Microscopes and Microscopical Accessories 193-320 5.* Balances and Weights 321-382 6.* Chemical Apparatus 383-816 7.* Botanical Apparatus 817-842 8. Gas Analysis Apparatus 843-886 9." Milk Analysis Apparatus 887-894 10. Refractometers 895-902 11." Oil Analysis Apparatus 903-926 12. Water Analysis Apparatus 927-933 13. Cement Testing Apparatus 934 - 946 14. Leather Testing Apparatus 947-949 15. Paper Testing Apparatus 950-951 16. Physico Chemical Apparatus 952 - 976 17.* Pyrometers 977-1006 18.* Calorimeters 1007-1022 19.* Seed and Soil Analysis Apparatus 1023-1042 20.* Spectroscopes and Polariscopes 1043-1078 21. Volumetric Apparatus '1079-1087 22. Anatomical Models 1088-1105 23. Meteorological Apparatus 1106-1124 24." Assay Apparatus 1125-1172 25 * » » A.-/. Chemicals 1187-1246 w3J§^==== ==/S^rffl • *Ti\\ -•' t^ y In 14 -CROSS STREET- HATTOTsf GARDEN, EC- MJ\ 11 w. U -R A41 A Selection of Scientific Books. We are always ready to obtain NEW and Second-hand Books not mentioned in the enclosed List, and to supply same at Publisher's price. General Chemistry. NAME OF AUTHOR Abegg & Herz Adie, R. H. . . Adie, R. H. . . Arraitage , F. P. Armstrong, F. Auld, S. J. M. Bailey, G. H. Barnett, E. de B. Bausor, H. W. Bayley, T. . . Behrens, Prof. Bernthsen, A. Blitz, Hall, & Blanchard Blount, B., & Bloxam.A.G. Boardman.T.H. & French.W. Briggs, W., & Stewart, R.W Brown, S. E. Brown, J. C. Browning.P.E. Bunge, G. . . Cain, J. C. Church, A. H. Classen, A. . . Clowes, Frank Clowes, F., & ColemanJ.B. Cohen, J. B. BOOK TITLE PRICE Practical Chemistry . . ..£060 Introduction to the Carbon Com- pounds . . • . ..026 Junior Chemistry . . ..026 A History of Chemistry . . 060 The Simple Carbo-hydrates and the Glucosides . . ..050 An Introduction to Quantitative Analysis . . . . ..050 The Tutorial Chemistry. Part I. 0 3 6 Part II. 2nd ed. . . ..046 Chemistry for Matriculation . . 056 Second Stage Inorganic Chemistry (Theoretical). 4th ed. ..046 The Preparation of Organic Com- pounds . . . . ..086 Junior Practical Chemistry . . 010 Senior Chemistry . . ..046 Elementary Science for the Certi- ficate Examinations. Section A : Chemistry . . ..020 Chemists' Pocket Book.. ..050 Micro-Chemical Methods of Analy- sis . . . . ..060 A Text Book of Organic Chemistry (trans, by Geo. McGowan.Ph.D.) 076 Laboratory Methods of Inorganic Chemistry . . . . . . 0 12 6 Chemistry for Engineers and Manufacturers. Vol. I. . . 0 10 6 Vol. II. . . 0 16 0 A Practical Text Book (illus- trated). Vol. I. . . . . 0 14 0 Vol. II. . . . . 0 16 0 Practical Chemistry, Part II. . . 016 Chemical Analysis, Qualitative and Quantitative . . ..036 Experimental Science. Part II. : Chemistry . . . . ..020 Practical Chemistry, 5th ed. ..020 Introduction to the Karer Elements 066 Text Book of Organic Chemistry for Medical Students ..060 The Chemistry of the Diazo-Com- pounds . . . . 0 10 6 Laboratory Guide . . ..066 Quantitative Chemical Analysis by Electrolysis . . . . 0 12 6 Practical Chemistry and Qualita- tive Analysis (illustrated) . . 076 Quantitative Chemical Analysis (illustrated) .. . . 0 10 6 Introduction to Quantitative Analysis . . . . . . 0 10 6 Elementary Practical Chemistry and Qualitative Analysis. Part I. 5th ed. ..026 „ II. 6th ,. ..036 Practical Organic Chemistry for Advanced Students . . ..036 NAME OF AUTHOR BOOK TITLE PRICE Cohen J. B. Theoretical Organic Chemistry . . £0 6 0 ,, Organic Chemistry for Advanced Students . . . . ..110 Cohn, A. I. . . Indicators and Test Papers . . 0 12 6 „ Tests and Reagents, Chemical and Microscopical . . . . 0 12 6 Cohn, Dr. L. A Laboratory Manual of Organic Chemistry (trans, by Alex. Smith) . . . . ..086 Crookes, Sir Select Methods in Chemical Wm. . . Analysis . . . . ..110 Dannerth, F. Textile Chemistry ..086 Desch, C. H. Inter-Metallic Compounds (In Preparation) Dittmar, W. Analytical Chemistry . . ..026 Don & Jame- First Year : Measurement and son Matter . . . . ..010 Second Year : Heat . . ..010 Third Year : Chemistry ..010 Dunstan, A. E. A Senior Experimental Chemistry 036 A Text Book of Practical Chemis- try for Technical Institutes . . 036 A First Year Course of Organic Chemistry for Technical Insti- tutes .. .. ..026 Dunstan, S. E. Elementary Experimental Chemis- try . . . . ..020 Dupre, A., & Inorganic Chemistry, a Short Wilson Hake Manual of . . ..060 Fenton,H.J.H. Outlines of Chemistry . . ..090 French, W. . . Practical Chemistry . . ..026 Fournier,E.E. Contemporary Chemistry . . 040 Freund, Ida The Study of Chemical Composi- tion . . . . . . 0 18 0 Furneaux, W. Elementary Chemistry, Organic and Inorganic . . ..026 Garrett, A. E. The Periodic Law . . ..050 Garrett.F.C., & An Elementary Course of Prac- Harden, A. tical Organic Chemistry ..030 Gattermann, L. Practical Methods of Organic Chemistry . . ..070 Gemmell.G.H. Chemical Notes and Equations . . 050 Gordon, J. H. Aids to Practical Chemistry ..026 Green, A. G. A Systematic Survey of the Or- ganic Colouring Matters . . 110 Grossman, J., The Elements of Sewage Treat- & Ramsay, Sir ment . . . . . . 0 15 0 W. Groves.C.E., & Chemical Technology of Chemistry Wm. Thorp in its application to Arts and Manufacturers. Vol. I. Fuel and its Applica- cation. By E. J. Mills (illustrated) .. . . 1 10 0 Vol. II. Lighting, Fats and Oils. By W. J. Dent, etc. (illustrated) .. ..100 Vol. III. Gas Lighting. By C. Hunt (illustrated) .. 0 18 0 (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1173 BAIRD ^TATLOCK. (LONDON) LTD. NAME OF AUTHOR Haas, P. Hale. A. J. Hanson & Dodgson . . Hardin, W. L. Haskins & Mac- Leod Hempel.Dr.W. Henry, T. A. Heusler F., & Pond, E. J. Hilditch, T. P. Hodgkinson, W. R. Hodgson, Dr. H. H. Hoff, V. T. Holleman & Cooper Holleman, Walker & Mott Hughes, A.M., & Stern, R. Irving, W. F. Jago, W. Jenk, T. Johnson, A.E. Jones, C. Jones, F. Kipping, F. S. Krauch, Dr. C. Lewes, E. I. . . Lewes. V. B. Lewes.V.B., & BrameJ.S.S. Lupton, S. . . McBain McGlannan, A. Martin, G. Meldola, R. . . Mendelieff, D. Merck, E., & Schenck, H. Meyer, E. Von BOOK TITLE Laboratory Notes on Organic Chemistry for Medical Students £0 Practical Chemistry for Engineer- ing Students An Intermediate Course of Labora- tory Work in Chemistry The Rise and Development of the Liquification of Gases Organic Chemistry Methods of Gas Analysis Aids to Chemistry The Chemistry of the Terpenes . . A Concise History of Chemistry . . A Third Year Course of Organic Chemistry for Technical Insti- tutes Qualitative and Quantitative Analysis (illustrated] The Chemistry of the Colloids (translated from the German of Dr. Victor Poschl) Lectures on Theoretical and Physi- cal Chemistry. Part I. „ II. „ III. A Text Book of Inorganic Chemis- try A Text Book of Inorganic Chemis- try A Method of Teaching Chemistry in Schools The Chemistry of the Coal Tar Dyes Inorganic Chemistry, Theoretical and Practical An Introduction to Practical In- organic Chemistry Chemistry for Beginners The Analyst's Laboratory Com- panion An Introduction to the Science and Practice of Qualitative Chemical Analysis, Inorganic . . Practical Inorganic Chemistry for Advanced Students Junior Course of Practical Chemis- try Inorganic Chemistry The Testing of Chemical Reagents for Purity (trans, by J. A. Williamson and L. W. Dupr6) Inorganic Chemistry The Elements of Organic Chemis- try Service Chemistry Laboratory Note Book for Chemi- cal Students Chemical Arithmetic Indicators (In Preparation) Inorganic Chemistry and Physics Researches on the Affinities of the Elements, etc. The Chemistry of Photography . . The Principles of Chemistry (illus- trated) Chemical Reagents History of Chemistry from the Earliest Times to the Present Day (trans, by Dr. M'Gowan) NAME OF PRICE AUTHOR BOOK TITLE PRICE Meyer, Lothar Outlines of Theoretical Chemistry ;n 2 6 (trans, by Prof. P. Phillips Ben- HP fl V son, and Prof. W. Carleton 030 Williams) .. ..£090 Miller, W. A. Introduction to the Study of In- 036 organic Chemistry . . ..036 Minchen, E. A. An Introduction to the Study of 066 Protozoa . . . . ..110 086 Molinari, E. Chemistry, Pure and Applied, Fart I. ..110 0 10 6 Moore, F. J. Outlines of Organic Chemistry . . 066 046 Neave, G. B. The Identification of Organic Com- pounds . . . . ..040 0 17 0 Nerast, Prof. Theoretical Chemistry (trans, by 0? B Prof. C. S. Palmer) . . . . 0 15 0 u u Newth, G. S. Elementary Practical Chemistry 026 Chemical Analysis, Quantitative 030 and Qualitative (illustrated) . . 066 A Text Book of Inorganic Che- 0 10 0 mistry (illustrated) . . ..066 M Chemical Lecture Experiments . . 060 Oldham, F. M. The Complete School Chemistry ..046 036 Olsen, J. C. Van Nostrand's Chemical Annual 0 12 6 0-4 o n Ostwald, W. The Fundamental Principle of \i U Chemistry . . . . ..076 086 OT ft Analytical Chemistry (trans, by / b Dr. McGowan) . . ..060 Conversations on Chemistry 0 10 6 Part I. (trans. by E.C.Ramsay) 066 „ II. ,. „ S. K. Turnbull 086 0 10 6 Principles of Organic Chemistry, in 2 vols. . . . . each 026 030 Palmer, J. D. Practical Text Book of Chemistry 046 0 16 0 Pattison Muir, The Elements of Chemistry . . 0 10 6 M. M. 046 A Treatise on the Principles of Chemistry. 2nd ed. . . 0 15 0 016 Perkin, F. Practical Methods of Inorganic 036 Mollwo Chemistry . . . . . . 0 1 Perkin, W. H. Organic Chemistry. New ed. . . 0 ' 066 Part I. . . ..040 „ II. .. ..040 Perkin, W. H., Introduction to Study of Chemis- 060 & Bevan & Lean try Perkin W. H. Conductivity of Electricity in Gases . . . . . . 0 16 0 Practical Physics, A Text Book of 0 9 0 Physics, A Text Book of . . 0 10 6 The Theory of Experimental Elec- tricity . . . . . . 0 8 a CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1183 BAIRD cVTATLOCK (LONDON) LTD. Mechanics, Statics, Dynamics. NAME OF AUTHOR Alexander & Thomson Ball, R. S. . . Barr, J. H. .. Barton, E. H. Bedford, E. J. Browne, W. R. Church, I. P. Clifford, W. K. Cotterill & Slade Cox, J. Dobb, W. J. . . Du Bois, A. J. Ferry, E. S. . . Franklin & Macnutt Glazebrook, R. T. Goodeve, T. M. Gray, A. Greaves, J. Greenhill, Sir A. G. Inglish, C. E. PRICE £110 016 0 10 6 0 10 6 BOOK TITLE Elementary Applied Mechanics A Class-Book of Mechanics Kinematics of Machinery Analytical Mechanics Introductory Mechanics The Student's Mechanics Foundations of Mechanics Mechanics of Engineering Notes and Examples in Mechanics The Elements of Dynamics. Part I., Books I. -III. Kinematics „ IV. Kinetic Lessons in Applied Mechanics — Vol. I. Parts I. and III. . . „ II. „ H- -• Complete . . Mechanics Examples in Elementary Me- chanics The Mechanics of Engineering. Vol. I. . . „ II. . . A Brief Course in Elementary Dynamics The Elements of Mechanics Mechanics and Hydrostatics : an Elementary Text Book, Theore- tical and Practical Part I. Dynamics II. Statics ,, III. Hydrostatics A Manual of Mechanics A Treatise on Dynamics Statics for Beginners Treatise OQ Hydrostatics Examples in Applied Mechanics and Elementary Theory of Structures . . . . ..026 010 150 086 076 060 030 030 066 090 050 NAME OF AUTHOR Jamieson.Prof. Lamb, H. Loney, S. L. . . Lcve, A. E. H. Low, D. A. Maxim, J. L. . . Morley, A., & Inchley, W. Norwell, A. . . 1 11 6 Parker, G. W. 2 2 0 Parkinson, S. 0 5 6 Pullen, W. W. 0 6 6 F. Roberts, H. A. Robinson, J.L. 0 6 0 Robson, H. . . 0 3 0 Sanderson, F. 0 2 0 W. 0 2 0 Taylor, J. E.. . 0 2 6 0 10 0 0 3 6 Thornton, A. 0 7 6 Wells, S. H. . . BOOK TITLE PRICE An Elementary Manual of Applied Mechanics . . . . ..£038 Hydrodynamics. 3rd ed. ..100 Mechanics and Hydrostatics for Beginners, nthed. .. 046 The Elements of Statics and Dynamics. I2th ed. ..076 Theoretical Mechanics . . . . 0 12 0 Applied Mechanics : Embracing Strength and Elasticity of Materials, Theory and Design of Structures, Theory of Mechanics and Hydraulics . . ..076 Experimental Applied Mechanics for Technical Students ..020 Elementary Applied Mechanics . . 030 Elementary Applied Mechanics (Statics), introducing the Uni- tary System . • 030 Elements of Mechanics . . 046 An Elementary Treatise on Me- chanics. 6th ed. . . . . 0 ! Mechanics . . . . . . 0 Williamson & Tarleton A Treatise on Elementary Dyna- mics Elements of Dynamics . . Principles of Mechanics Hydrostatics for Beginners . . 0 Theoretical Mechanics . . Theoretical Mechanics, Solids . . 0 Theoretical Mechanics, Fluid . . 0 Theoretical Mechanics, Solid? . . Practical Mechanics . . . . 0 An Elementary Treatise on Dynamics . . Spectroscopy. NAME OF AUTHOR Baker, T. T. . . Baly, E. C. C. Gissing, C. E. Lockyer, J. N. Roscoe & Schuster BOOK TITLE PRICE The Spectroscope . . ..£050 Spectroscopv . . . . 0 12 6 Spark Spectra of the Metals ..076 Studies in Spectrum Analysis . . 050 Spectrum Analysis. 4th ed. . . 110 NAME OF AUTHOR Tingle & Lan- dane Watts, W. M. BOOK TITLE Spectrum Analysis PRIC £0 12 An Introduction to the Study of Spectrum Analysis . . . . 0 10 Pharmacy. NAME OF AUTHOR Attfield, Dr. J. Beddoes, T. P. BOOK TITLE PRICE Chemistry, General, Medical, and Pharmaceutical . . . . £0 15 0 Preservers' Formulary and Index of Pharmacy . . ..026 NAME OF AUTHOR French, H. . . Gadd, H. W. BOOK TITLE Medical Laboratory Methods and Tests . - £0 A Synopsis of the British Pharma- copoeia, 1898 . . ..01 5 0 CROSS STREET • HATTO>J GARDEN, E-C 1184- BAIRD &TATLOCK. (LONDON) LTD. NAME OF AUTHOR Gadd H. W. BOOK TITLE PRICE Drugs, their Production, Pre- paration, and Properties . . £0 5 0 The Poisons and Pharmacy Act, 1908 . . . . ..010 Hudson-Cox, F. The Pocket Pharmacopoeia 036 NAME OF AUTHOR Squire, P. W. Stark, A. C. . . Whitla, Sir W. BOOK- TITLE PRICE Pocket Companion to the British Pharmacopoeia . . ..£07 Aids to Practical Pharmacy . . 02 Elements of Pharmacy, Materia Medica, and Therapeutics. 5th ed. . . 0 16 Microscopy. NAME OF NAME OF AUTHOR BOOK TITLE PRICE AUTHOR BOOK TITLE PRICE Bousfield.E.C. Guide to the Science of Photo- Squire, P. W. Methods and Formula? us.ed in Carpenter, W. Micrography . . -..£060 The Microscope and its Revela- the Preparation of Animal and Vegetable Tissues for Micro- scopical Examination, including B. tions . . . . ..180 the Staining of Bacteria . . £0 3 6 Cross, M. I. Modern Microscopy . . ..060 Whipple, G. C. The Microscopy of Drinking Water 015 0 Gait, Hugh . . The Microscope of the more Wright, Sir A. Principles of Microscopy . . 110 commonly occurring Starches . . 036 E. Vol. I. The Microscope and its Accessories . . . . 0 14 0 Griffiths, Dr. An Elementary Text Book of the Vol. II. The Microscope, its J. W. Microscope . . ..076 Revelations . . . . 0 14 0 Scales. F. S. . . Practical Microscopy. 2nd ed. . . 050 Zsigmondy- Colloids and the Ultramicroscope 0 12 6 Alexander Physiological Chemistry. NAME OF NAME OF AUTHOR BOOK TITLE PRICE AUTHOR BOOK TITLE PRICE Abderhalden- Text Book of Physiological Che- Heitzmann, L. Urinary Analysis and Diagnosis Hall, Defren mistry . . . . ..£110 by Microscopical and Chemical ' Bunge, G. Text Book of Physiological and Examination . . . . £0 10 6 Pathological Chemistry . . 0 16 0 Milroy, J. A.,& Practical Physiological Chemistry 050 Hall, A. J. Student's Note Book of Phy- Milroy, T.H. siological Chemistry for the Thudichum, J. Aids to Physiological Chemistry .. 016 Laboratory . . ..026 L. W. Hawk, P. B. Practical Physiological Chemistry 0 16 0 Foods 6? Drugs. NAME OF NAME OF AUTHOR BOOK TITLE PRICE AUTHOR BOOK TITLE PRICE Bolton & Fatty Foods, their Practical Parry, E. H. Foods and Drugs — Revis Examination . . . . £0 10 6 Vol. II. The Sale of Food and Greenish, H.G. Microscopical Examination of Drugs Acts . . ..£076 Leach, A. E. Foods and Drugs. 2nd ed. . . 0 12 6 Food Inspection and Analysis . . 1 11 6 Pearmain, T. The Analysis of Food and Drugs. H., & Moor, Part I. . . . . ..060 Mitchell, C. Flesh Foods, with Methods for C. G. „ II. . . . . ..060 Ainsworth Moor, C. G. . . their Chemical and Microscopical and Bacteriological Examination 0106 Suggested Standards of Purity for Sherman, H.C. Chemistry of Foods and Nutrition 066 Thresh, J. C. Preservatives in Food and Food Examination . . . 0 14 0 M Foods and Drugs . . ..076 Aids to the Analysis of Foods and Drugs . . . . ..036 Whymper, R. Cocoa and Chocolate, their Che- mistry and Manufacture . . 0 15 0 Parry, E. H. Foods and Drugs — Wiley, H. W. Foods and their Adulteration ..110 Vol. I. Analysis of Foods and Wynter Blyth, Foods, their Composition and Drugs . . . . ..110 A. & M. Analysis . . Forensic Medicine 6? Toxicology. NAME OF NAME OF AUTHOR BOOK TITLE PRICE AUTHOR BOOK TITLE PRICE Hawthorne . . Forensic Medicine and Toxicology £060 Witthaus.R.A. Manual of Toxicology . . . . £1 10 0 Murrell, W. . . Aids to Forensic Medicine and BAIBD ^IXTLOCK (LONDON) LTD. Gas Analysis. NAME OF AUTHOR Hempel, W. Lunge, G. NAME OF AUTHOR Andes, L. E. Blount, Ber- tram Bockmann.Dr. Fr. Booth. W. H. Butterfield, W. J. Atkinson Dcsch. C H. Dumesny & Noyer Dyson & Clarkson Geschwind, L. Grant, j . Gross, E. Groves, Thorp, & Dibdin BOOK TITLE Methods of Gas Analysis Handbook of Technical Analysis Hodgson, H.H. Hehner, O. . . Gas PRICE £0 10 0 0 10 6 NAME OF AUTHOR Royle, H. M. Travers, M. W. BOOK TITLE PRICE Gas Manufacture, Chemistry of .. £012 6 The Experimental Study of Gases 0 10 0 Technology. BOOK TITLE Vegetable Fats and Oils Chemistry for Engineers and Manufacturers. Vol. I. » »,, H. Celluloid . . » Water Softening and Treatment Gas Manufacture, the Chemistry of. Vol. I. 4th ed. „ II. 3rd ,, (Ready shortly) The Che'mistry and Testing of Cement Wood Products, Distillates, and Extracts Chemical Works The Manufacture of Alum The Chemistry of Breadmaking . . Hops Chemical Technology, or Chemis- try in its Application to Arts and Manufactures. Vol. I. Fuel and its Appli- cations „ II. Lighting „ III. Gas Lighting IV. Electric Lighting Celluloid, its Manufacture, Appli- cations, and Substitutes Butter, its Analysis and Adul- terations NAME OF PRICE AUTHOR £0 10 6 Hudson, O. F. Hurst, G. H. 0 14 0 Roller, Dr. T. 0 16 0 Leeds & Butter- 0 5 0 field Lunge, G. 0 7 6 0 7 \ 6 0 10 6 0 10 6 Martin, G. . . 1 1 0 M'Intosh, J.G. 0 12 6 0 5 0 0 10 6 Shaw, Simein 1 10 0 Simmons, W.H. 1 0 0 & Appleton, 0 18 0 H. A. 1 0 0 Southcombe, J. E. 1 5 0 Vincent, C. . . Wagner, R. . . 0 3 6 Waterbury, A. BOOK TITLE PRICE Iron and Steel (In Preparation) . . Textile Soaps and Oils . . ..£050 The Utilisation of Waste Products 076 Acetylene : the Principles of its Generation and Use . . ..086 The Manufacture of Sulphuric Acid and Alkali. Vol. I. 4th ed. . . „ II. 3rd ,, . . .220 ,, III. 3rd „ .. 1 10 0 ,, IV. (In Preparation) . . Coal-Tar and Ammonia. 4th ed. 220 The Technical Chemists' Handbook 0 10 6 Industrial and Manufacturing Che- mistry, Organic . . ..110 Spirit Varnishes and Spirit Varnish Materials Technology of Sugar . . . . 0 10 The Re-issue of the Chemistry of the several Natural and Arti- ficial Heterogeneous Compounds used in the Manufacturing Por- celain Glass and Pottery . . 0 10 The Handbook of Soap Manufac- ture .. .. ..08 Paints, Oils, and Varnishes (In Press) Ammonia and its Compounds . . 05 Manual of Chemical Technology . . 112 Cement Laboratory Manual . . 04 CROSS STREET • HATTCXN GARDETST, E- C 1186 BAIRD &TATLOCK (LONDON) LTD. Price List of Pure Chemicals. Standard Solutions, Bacteriological Stains, etc. CONTENTS. T. Microscopes Dyes (Grubler's) T. ,, ,, in solution T. „ ,, Soloids (Burroughs, Wellcome & Co.'s) T. Disinfectants T. Merck's Guaranteed Pure Reagents T. Chemicals and Acids, etc. T. Fertilizers and Weed Killers T. Standard Solutions s. Minerals in Sets T. ,, for Analysis T. Solmedia T. Sterile Culture Tubes T Collections T. Voltoids T. Pyrogallic Acid (Special Prices) T. Litmus Books and Test Papers Directions for Making Reagents PACK 1191 "93 "94 1196 1200 1234 "34 1238 1239 1241 1243 1244 1240 1245 1246 1240 ACIDS, ETHERS, and other Dangerous or Inflammable Chemicals. — As the Railway Companies will only carry these under special conditions and at an extra rate, the minimum being 55., we recommend clients to order the largest possible quantity in one consignment, and so reduce the cost of carriage. Prices subject to alterations. — The prices quoted in each column are only for the quantities mentioned, with the exception of J-lb. lots, which will be charged at Ib. rate ; under |-lb. will be charged at oz. rate. Any Chemicals not specified will be obtained to order. Estimates for larger quantities than specified in this List on application. All* former Chemical Price Lists cancelled. Full value for our Cases and our Empty Bottles when received back in good condition Carriage Paid. We have equipped a Laboratory for testing the purity of Chemicals, preparing Standard Solutions and Bac- teriological Stains, &c. ; the quality of these may be relied on, as they are all thoroughly tested by a competent Chemist. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1187 BAIRD & WLOCK (LONDON) LTD. When ordering please refer to note on preceding page re carriage of Acids, Ethers, 6?c., and note minimum rate charged by Railway Go's. CROSS STREET • HATTQTST GARDE1ST, E-C BAIRD &.TATLOCK (LONDON) LTD. SECTION No. 25. GRUBLER'S STAINS. Powder and in Solution (specially selected for Bacteriological Work). POWDER, in Original Bottles. ,:ains not specified below will be obtained to order. (Bottles with metal screw caps are included in prices.) Per 5 gr- Per 10 gr. Per 5° gr. Per Per 10 gr. Per bottle. bottle. bottle. bottle. bottle, bottle. s. d. s d. i. d. s. d. 5. d. s. d. etin, blue o 6 o 9 3 o Brilliant blue o 10 i 3 5 6 lid, carminic, pure (Mayer) 2 o 3 6 14 o Brasilin o 6 o IO 3 6 1, ,, ammoniacal (Hoyer) 2 6 4 6 Brilliant Cresyl-blue o 8 i o 4 o 1 , green O 7 o 10 3 6 ,, green o 8 i o 4 o [ridin, orange O 8 I o 4 ° Carmalum, dry i 4 2 o 7 ° hm, carmine, dry (Griibler) I 3 2 3 IO O Carmine, rubr. opt. o 9 I 2 4 6 f:hyl, violet 0 8 I o 4 o Carmine ammonia (Hoyer) 2 6 4 9 Izarin I., dry o IO I 3 3 6 China blue 0 8 I o 4 ° Izarinblue S. (Ehrlich) o 6 O ii 3 6 ,, green O 6 o IO 3 6 Izarine sulp. acid (Metschnikoff) 0 8 I o 4 ° Chlorhydrin blue (Kuhne) o 6 o 9 :ali blue o 6 O ii 3 6 Chrysoidine 0 6 0 9 3 ° ,, green 0 8 I o 4 ® Congo red (Nissl) o 8 I o 4 o :annin o 6 I o 4 ° Corallin, soluble in spirit and soda ilinblue soluble in alcohol o 8 I o 4 ° (Strassburger) o 6 o 9 3 ° ,, ,, water o 8 I o 4 o Corallin, soluble in water o 6 o 9 3 ° tline, blue-black o 8 I 0 4 ° Chromogen for Neuroglia (Weigert) 0 6 o IO 3 6 yellow o 6 o IO 3 6 Cresylechtviolet o 7 o II 4 ° .lingreen (Strassburger) 0 6 o 10 3 6 Crystal violet (Hochst) . . 0 8 I o 4 o Itline Chlorhydrate o 6 0 9 3 ° Cyanin 9 6 17 o — I,, Sulphate o 6 o 9 3 ° Dahlia 0 8 I 0 3 6 J-amin o 8 I o 4 ° Diamantfuchsin o 8 I o 4 O A'antia o 9 I 3 5 ° Direct Bright Cotton Blue o 8 I 0 4 f 1> blue o 6 o IO 3 6 Echtgriin (Dinitrosoresorcin)Platner o 8 I o 3 6 1 carmine 0 6 o 10 3 6 Eosin, soluble in water, yellow shade o 7 o ii 4 ° Air, I., Giemsa, dry per grin. 6/- . . — ,, ,, ,, blue ,, o 7 o IO 3 6 II 3/6 — — ,, ,, alcohol o 7 0 II 4 o II., Eosine, ,, ,, 4/9 — — pure for blood corpuscles . . o 8 I o 4 o •izoazurin o 8 I o 4 6 A.G. o 8 I 0 4 O •izo-purpurin (Birch-Hirschfeld) o 7 o II 4 o extra B.A. 0 8 I o 4 ° • brich's scarlet (Griesbach) o 7 o II 4 ® methylene blue 2 6 4 6 — • ndi-Ehrlich-Heidenhain's triple ,, (Jenner stain 2 o 3 6 16 6 May-Grunwald) 2 6 4 6 — narckbrown (Weigert) o 5 o 8 2 6 Leishmann 5 o 9 0 — u de Lyon (Greisbach) 0 7 o ii 4 o Reuter . . 5 o 9 o — ax carmine, dry I 6 2 6 II O Erythrosin, pure o 9 i 3 5 o deaux red (Greisbach) x^^S o 8 I o 4 o Fluorescein (Kuhne) o 9 I 3 n 5 ^ ?^£v OCHEMICAL AND SCIENTIFIC~APPARATUS AND PURE CHEMICALS '•' W iJ. J ^3dS2z5P 5^ **^=— t gjlr1 1189 BAIRD &TXTLOCK (LONDON) LTD. Griibler's Stains (i-ontinuett) . Per Per Per IVr Per Per 5gr. iogr. 5°gr- 5gr. 10 gr. 3°gi bottle. bottle. bottle. bottle. bottle. lottlf s. d. s. d. s. d. 5. d. s. d. s. a Fluorescin Potassium o 8 I o 4 ° Naphthylamincbrown (Kaiser) o 6 o 9 3 Fuchsine, for bacteria o 6 o 9 3 6 Xaphthylamineyellow (Naphthol- „ acid (Weigert) o 6 o 9 3 6 yellow) o 7 O IO 3 ' Fuchsin-inethylene blue i 6 2 0 7 ° Naphthol green B o 7 0 10 3 ' Gallein paste o 4 o 6 2 0 Neutral red i 3 I 9 8 < i, .. dry I O I 6 6 o Nile blue chlorhydrate . . o 9 i 3 S ' Gallocyanin o 6 o 9 3 ° ,, sulphate o 9 i 3 - Gentian violet (Gram) o 6 o 9 3 ° Night blue for flagella — • o 8 a Haemalum, dry (Gruhler) I 2 i 9 7 ° Nigrosine o 6 o 9 Haemateifl, purest (Mayer; 4 6 8 6 — Orange G. " 5 o 8 Haematin Ammon (Mayer) 4 6 8 6 — Orceln, pure (Israel, Unna) 2 6 4 6 - Haematoxylin, purest crystal I 0 I 9 8 6 ,, special 2 6 4 6 - Haematoxylin-eosin Hclianthin i 6 o 6 2 6 o 9 II 0 2 6 Orseille (extract) Phloxinred (Birch-Hirschfeld) o S o 5 I 0 r Hofmann- violet o 8 I O 4 ° Picrocarmine (Cuccati) 3 6 <) 0 - Indigo carmine o 9 i 3 5 o (Hoyer) 3 6 6 6 - Induline o 8 1 0 4 " ,, (Ranvier) 3 6 6 6 ~ Iodine green (Griesbach) O IO I 4 5 6 Picro-lithia carmine dry 3 3 6 o - lodine-eosin I 0 i 6 6 o Ponceau, P.R. o 6 o 9 3 Jenner's stain 2 3 4 o — Purpurin I 0 i 6 Kreso fuchsin 3 6 6 o — Pyronin o 9 I 2 5 Irishman's blood stain powder 5 ° 9 o — Resorcin-Fuchsin 3 6 6 o - Light green o 6 o 9 3 o Rosaniline (base) o 9 2 5 Litmus Neutral 12 6 Rosanilinehydrochloride o 8 0 3 • Magdala red . . per grm. 1/2 5 6 II O — Rosaniline nitrate o 8 O 4 Magenta red o 8 I 0 4 6 ,, sulphate o 8 o Malachitegreen o 8 I 0 4 ° Rose Bengal (Griesbach) o 8 2 (Hochst) o 8 I O 4 o Rubin S. o 7 Oil „ cryst. Ruthenium red (Mangin) 4/- per o.i (Zinc Chloride double salt) o 8 I O 4 o grm. Martius yellow . . o 6 I O 3 o Safranine o, soluble in water May-Griinwald Colour 2 6 4 9 — (Pfitzner, Flemming) o 8 I 0 Methvlblue o S I O 4 6 soluble in spirit 5 6 11 O Methvl-eosin o 8 I O 4 6 ,, pure (Pheno-Safranine) . . o 9 I 2 Methyl-green, cryst. oo (yellowish) O IO I 4 5 6 Scharlach R. o 8 I 0 Methyl-orange o 6 o 9 3 o Smaragd green o 8 I 0 Methyl-violet, iB o 7 0 II 3 6 Spillcr's purple . . per grm. 1/9 7 9 2B o 6 o 9 3 o Soudan III. o 8 I O 5B o 7 on 3 6 Thionine pur. 2 6 4 0 6B (Hexa-methyl- Toluidineblue (Hoyer) o 8 I O violet) o 8 I O 4 ° Trypan Blau O IO i 6 B.N. o 8 I O 4 ° Roth O IO i 6 Methylene-blue, for bacteria (Koch) o 8 I 0 3 & Uranin o 8 I 0 „ medic, pur. (Gutt- Vesuvinebrown (Koch) o 6 o 9 mann & Ehrlich) 0 10 I 4 5 ° Victoriablue 4R (Lustgarten) o 8 I 2 Methylene-green O IO I 4 5 ° Waterblue (Unna) o 8 I 0 Methylene-violet o 8 I O 4 o Wollschwarz (Loeffler), for bacteria Mucicarmine, dry (Mayer) 3 6 6 9 flagella o 7 O IO Muscarin (dye) I O I 6 8 o Wright's blood stain per grm. i/- 4 6 8 6 Naphthylene blue R. cryst. O IO 1 4 5 6 Curare . . per grm. 4/- 19 o 36 o - See page 1206 for Aniline Colours suitable for Dyeing Experiments, &c. See page 1223 for Griibler's Paraffin Wax. Griibler's Stains for Injection. (Prices do not include bottles.) s. d. Indigo-carmine lA. opt., for Heidenhain's o method of injecting kidney i grm. Injectionmass, cold (Beale), red or blue 50 grms. Xeutralred, pure (Ehrlich) for injection into o 7 living tissue 2.5 grms. o 9 Methylene blue, rect. (Ehrlich), for injection into living tissue Prussian blue, best, highly soluble in distilled water, without the addition of oxalic acid, particularly suitable for the preparation of injection masses . . 10 grms. Glycerine, chemically pure, in bottles of about 20 c.c. each Glycerine jelly, chemically pure, in bottles of about 20 c.c. each 1190 BAIRD &TATLOCK (LONDON) LTD. Stains in Solution. For Bacteriological Work, &c. Prepared from Griibler's Selected Dyes in our own Laboratory (Prices do not include bottles.) Per 100 grms. s. d. kannin tincture . . . . ..20 -Methylene blue eosin (Reuter) . . ..36 "um-carmine (Grenacher) . . ..08 .urn-gentian violet (Unna) . . . . i 8 .Icohol-carmine (Grenacher) . . ..19 „ (Mayer) . . . . ..20 mmonia-carmine (Gerlach) . . ..08 „ (Ranvier's) . . . . i 6 onia picrocarmine . . . . ..19 niline-water gentian violet (Gram) . . o 10 blue solu. (Giemsa) . . . . ..66 ndi-Ehrlich-Heidenhain's triple stain . . 23 •acic acid carmine (Arcangeli) . . . . i 6 orax-carmine (Grenacher) aqueous . . 08 alcoholic . . 20 orax indigo carmine (Merkel) . . . . i 6 „ methylene blue (Unna, Sahli) . . 20 irbol-fuchsine (Ziehl-Neelsen) . . o 10 irbol-gentian violet . . . . . . i o irbol-methlyleneblue . . . . . . i 6 irbol-thionine . . . . . . ..20 1'irminic acid, 5% alcohol . . ..26 urmalum (Mayer) . . . . . . i o >chineal tincture (Mayer) . . . . i 8 >rallin soda (Strassburger) . . ..20 ystal-violet (Bender) . . . . . . i 6 irlich's triple stain for eosinophilous cells . . 29 ulich's triacid stain for neutrophilous granules . . . . . . ..26 5sm aqueons . . . . . . o 10 alcholic, ordinary . . . . . . i 8 sat. alcoholic 4 6 Eosin-glycerine Eosin-haemalum Eosin-haematoxylene (blood stain) (Ehrlich) .. „ „ -glycerine cone. (Renaut) Eosin-methylene blue (Laurent) . . (May-Grunwald) „ (Willebrand) Ferrotannant for flagellas Fluorescin-methylene blue (Czaplecosky) Formalin-gentian violet (Raebiger) Fuchsine, aqueous „ sat. alcoholic Fuchsin-methylene blue Gabbet's bacteria stain, carbol-fuchsine I. . . ,, methyleneblue, sulphuric acid II. Gentian violet aqueous „ ,, alcoholic saturated Gieson's solution Giemsa's stain Glycerine-alum haematum (Rawitz) Gram's iodine staining solution Haemalum (Mayer) ,, glycerine cone. Haematoxyline (Boehmer) „ (Hansen) (Gage)' .. ale. (Kleinenberg) (Delafield) (Kultschitzky's) acid (Ehrlich Per 100 grms. s. d. , 2 O r 6 i 6 i 6 3 6 4 6 4 6 4 o 1 3 2 6 1 3 o 8 4 6 2 O 0 IO 1 6 i 6 4 6 0 8 6 6 1 6 i o 0 9 1 6 .1 9 3 8 6 6 3 6 •CHEMICAL AND SCIENTIFIC .APPARATUS AND PURE CHEMICALS. BAIR.D &. IMLOCK (LONDON) LTD. Stains in Solution (continued). Haematoxyline (Heidenhain) double stain (Weigert) for spinal cord, two solutions, Nos. I. and II. Haematoxyline chrome salt — I. Chrome salt II. Haematoxyline Hofmann's blue . . Iron-haematoxyline (Heidenhain) solution I. (Heidenhain) solution II. Tod-eosin (Unna) Jenner's stain Kernschwarz Kreso-fuchsin Leishman's stain Lithium-carmine (Orth) Lithium picro-carmine Litmus solution, prepared according to Kubel & Tiemann, per litre, 6/6 Lceffler's Xo. I. solution for flagellae „ Xo. II. „ ,, alkaline methylenblue for bacteria Methylene blue soap solution (Xissl) aqueous sat. alcoholic borax carbol corallin solution (Pappenheim) sulphuric acid Methyl blue, aqueous „ sat. alcoholic neutral red Per ioo grms. $, d. o 9 13 0 9 1 o 3 o 4 6 2 4 2 6 4 6 i 6 i 6 2 0 0 IO I O I O i 3 4 6 i 3 1 3 2 0 i 3 i 3 4 6 i 6 Methyl green, aqueous „ „ pyronin solution (Pappenheim Unna) Methyl violet, oxalic acid solution (Weigert) . . sat. alcoholic solution M Oiler's solution Xeisser's stain for diphtheria (a) (b) .. Xeisser's triple stain Orcein solution, acid (Unna) neutral (Unna-Tanzer) Paracarmine (Mayer) Picric-anilinblue Picric-nigrosine (Strassburger) Picric acid solution ,, ,, ammoniac Picrocarmine (Ranvier) (Weigert) .. Polychrom-methylenblue (Unna) Romanowsky's stain Rubin and orange solution Roux's blue, for diphtheria bacillus Safranine-aqueous Safranine-aniline solution (Babe's) Safranin polychrome methylene blue solu. . . Sherrington's fluid Toison's fluid Toluidin's blue solution (Pugh) Tworts stain Weigert 's elastica stain Wright's blood stain Per 100 grms. s. d. I 0 1 6 2 0 4 6 0 3 1 o 0 6 4 o 2 0 1 8 i 8 i 3 i o o 7 0 7 1 6 i 6 1 8 4 6 2 6 2 6 1 3 2 0 2 0 i 3 2 4 4 4 Hardening and Fixing Reagents. Alcohol, absolute 90 per cent. , 84 ., „ and acetic acid Erlicki's fluid . . Fleming's solution Fol's solution . Per oz. s. d. o 5 o 5 o 4 o 6 o 4 Per Ib. s. d. 5 o 4 9 4 o 6 o 4 o 14 o 4 o Klein's solution Mayer's albumen Muller's fluid .. with alcohol Perenyi's solution Rabl's fluid Per oz. s. d. 0 5 1 0 o 4 o 6 o 4 s. 6 i 3 6 4 Corroding and Decalcifying Solutions. Ebner's Solution . . Eau de Javelle Eau de Labarraque Per oz. s. d. o 6 O 2 O 2 Perl s. d. 6 o 2 0 2 0 1192 BAIRD c^TATLOCK (LONDON) LTD. Microscopic Stains. (BURROUGHS, WELLCOME & Co.) Trade Mark — " Soloid " Brand. The word " Soloid " is a brand which designates fine products manufactured by Burroughs, Wellcome & Co. To ensure the supply of these pure and reliable preparations this brand should always be specified when ordering. The tendency of solutions of the aniline dyes to decompose has always been a source of trouble in micro- scopic work. The " Soloid " Microscopic Stains enable solutions to be prepared in small quantities when required. List of " Soloid " Brand Microscopic Stains, in tubes containing six tabloids. " SOLOID " Brand- BISMARCK BROWN, pure, o.i gm. BORAX METHYLENE BLUE EHRLICH'S TRIPLE STAIN EOSIN, pure, o.i gm. EOSIN-METHYLENE BLUE, 0.05 gm. (Louis Jenner) EOSIN AZUR., for Giemsa's Staining with one solution, 0.038 gm. FUCHSINE, pure, o.i gm. GENTIAN VIOLET, pure, o.i gm. GRAM'S IODINE SOLUTION, 15 c.c. Per doz. tubes. s. d. 80 80 10 o Per doz. tubes. 8 o 18 8 SOIOID " Brand HVMATOXYLIN, pure, o.i gm. . . HYMATOXYLIN (Delafield) METHYLENE BLUE, pure, o.i gm. METHYL VIOLET, pure o.i gm. SODIUM CARBONATE, .05 gm. THIONIN BLUE, pure, o.i gm TOISON'S BLOOD FLUID ROMANOWSKY STAIN (Leishman's Powder] 0.015 §m- ROMANOWSKY STAIN (Wright's Modification] 0.05 gm. d. o o o o o o o DIRECTIONS FOR USE. The amounts of distilled water and absolute alcohol respectively required to produce saturated solutions of certain dyes in common use are indicated in the following table. In all cases the " Soloid " product should be thoroughly powdered before it is shaken up in the solvent. " Soloid " Produce of o.i gramme of Dye. Water (c.c.) Alcohol (c.c.) Bismarck Brown, pure 7 7 Fuchsine, 10 2-5 Gentian Violet, 7 7 Haematoxylin 2 I Methyl Violet, 5 I Methylene Blue, 7 7 Thionin Blue 5 10 Aqueous dilutions of the above, containing 5 to 10 per cent, of these saturated solutions, are well adapted for ordinary stain- ing purposes. Various other solutions, ready for immediate use, may be prepared from " Soloid " Microscopic Stains according to the following directions : — Eosin. — To obtain a solution of eosin suitable for general staining, one " Soloid " product may be dissolved in 20 c.c. of 50 per cent, pure alcohol. This gives a 0.5 per cent, solution. Loefiler's Alkaline Methylene Blue.— Dissolve one " Soloid " Methylene Blue in 7 c.c. of absolute alcohol, and add 25 c.c. of distilled water to which one drop of Liquor Potassae P.B. has been added. Aniline Gentian Violet. — Dissolve one " Soloid " Gentian Violet in 7 c.c. of absolute alcohol ; and add 63 c.c. of a freshly filtered saturated solution of aniline oil in distilled water. Zeibl's Carbol Fuchsine. — Thoroughly powder one " Soloid " Fuchsine in 3 c.c. absolute alcohol ; add 22 c.c. of 5 per cent, aqueous solution of carbolic acid ; shake well and filter before using. Gram's Iodine Solution. — Dissolve one " Soloid " product of reagent A in 10 c.c. of distilled water ; add one of reagent B, and when solution is complete, dilute to 15 c.c. with distilled water. Carbol Thionin Blue. — Dissolve one " Soloid " Thionin Blue in 100 c.c. of a 5 per cent, aqueous solution of carbolic acid. Borax Methylene Blue. — Dissolve one " Soloid " Borax Methylene Blue in 10 c.c. of distilled water. Delafield -s Haematoxylin. — Dissolve one " Soloid " Haematoxylin (Delafield) in 10 c.c. of a 25 per cent, solution of glycerin in water. Eosin-methylene Blue (Louis Jenner's Stain). — Dissolve one " Soloid " product in 10 c.c. of pure methyl alcohol. Romanowsky's Stain (Leishman's Modification). — Dissolve one " Soloid " product in 10 c.c. of purr methyl alcohol. In the cases of Loeffler Alkaline Methylene Blue, Aniline Gentian Violet, and Zeihl's Carbol Fuchsine, the solutions obtained as above are only approximately equivalent to those prepared according to the original formula. The figures avoid small fractions in measurement ; this enables the solution to be prepared more readily without diminishing the efficiency of the stain. .CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1193 f BAIRD &TATLOCK (LONDON) LTD. Disinfectants, Formalin, Schering's 40%. i gal. £ gal. i lb. 12/6 144/- 6/6 76/- 1/6 17/6 lib. 1/1 12/6 J lb. bottles. 9d. each ) bottle 8/6 per dozj free. Formaline Tablets, Schering's (Paraform'.) i lb. | lb. 6/- 3/- 60/- 30/- Formaline Disinfecting Powder, in tins, I/- each; 11/6 per doz. Formochlorol Charges for autoclave, per doz., 50/-. lb. tins (about 450 tablets_to the 1 2/- each. 2 1/- per doz. Urotropine, Schering's. i oz. bottles. 2/4 5 grain tablets (boxes of 50). 1/9 5 grain tablets (boxes of 100). 3/5 each. Kerol Disinfectant Fluid. Small bottles. 6d. Large bottles. 11- \ pint tins. H- i pint tins. 1/6 each. Jeyes' Fluid. | gallon tins. 4/- i gallon tins. 7/- each. ' Small bottles. 6d. 5/6 Large bottles. I/' 10/- J pint tins. lOd. 9/- i pint tins. 1/3 each. 14/- per doz. Chinosol, pure powder. J gallon drums. 3/6 i gallon drums. 6/- each. i 1/11 2 4 3/8 7/2 8 ll/- 16 oz. bottles. 2 1/- each. Chinosol in compressed tablets. Tubes of 12. II- 4 oz. bottles. 7/6 8 oz. bottles. 13/- each. 14 -CROSS STREET • HATTCTN GARDEN, E- C 1194 BAIRD &.TXTLOCK (LONDON) LTD. Jeyes' Special Fluid. " CYLIN." Bottles. II- H/- | gallon drums. pint tins. I/- ll/- Pint tins. 1 /6 each. 16/- per doz. i gallon drums. 7/- each. Izal." Disinfectant (non-poisonous). 4 6d. 5/6 8 II- II /- Lysol. 8 l/- Trikresol (Schering's). i I/- 16 1/9 24 2/6 28/- 48 oz. bottles. 4/6 51/- 32 oz. bottles. 1/9 i gall, drums. 6/- each. 70/- per doz. i gall, drums. 10/6 each. i Ib. bottles 3/- each. 'MICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &. raTLOCK (LONDON) LTD. JODXALIUM K»UU» JODATUM PUBlSS Merck's Guaranteed Reagents for Analytical Work AT MERCK'S ORIGINAL PRICES. These are stocked in Merck's Original Bottles, under strict guarantee of their conformity with the standards of purity established by E. Merck. WHEN ORDERING PLEASE SPECIFY "MERCK'S GUARANTEED REAGENTS.' Prices quoted below include cost of bottles, which are not returnable. (g.s.6. signifies glass stoppered bottles.) Per Per Per Per oz. 4oz. Jib. lb. bott. bott. bott. bott. s. d. s. d. s. d. s. d. Acid Acetic, extra pure glacial 1.064 g.s.6. — — I 2 2 I , „ anhydrous g.s.6. — 2 0 3 9 7 3 , Arsenious, pure powder . . — — — 1 4 , Boric, extra pure fused, for analysis of Silicates, ace. to Jannasch . . . — 2 I 4 i 8 i , Chromic, pure, for the estimation of CO2 g.s.6. — — i 6 2 10 „ extra pure cryst. free from Sulphuric Acid g.s.6. — I 3 2 3 4 3 , Citric, perfectly white, extra pure cryst. — I O i ii 3 9 , Gallic, white, extra pure cryst. — I O i ii 3 7 , lodic, pure anhydrous g.s.6. 3 5 12 8 — . Molybdic, extra pure, free from Ammonia and Nitric Acid 3 8 6 10 ii 6 , Naphthylamin-sulfonic alpha, extra pure • . . i 5 5 2 — — , Oxalic, extra pure cryst. . i i I 10 , Phospho-Molybdic, cryst. g.s.6. 2 9 10 0 — — ,, Tungstic, extra pure cryst., absolutely free from NHS and N 2O5 g.s.6. i 5 4 8 — — , Phosphoric, extra pure 1.7 (syrupy consistency) g.s.6. I 2 2 0 glacial (Meta-) — — i 8 3 I ,, anhydrous, perfectly white . . £•«.& — I 2 2 I 3 7 , Sulpho-anilic (sulphanillic), white cryst. . — i 6 3 o 5 10 , Tannic, extra pure i 5 2 7 4 9 Alcohol Amylic, extra pure .-^X^Oh I. E- ^,> C- M w* 1196 f fi BAIRD &TATLOCK (LONDON) LTD. mm y *•> W mm Merck's Guaranteed Reagents (continued). Per Per Per . • : oz. 4oz. Jib 1!.. bott. bott bott. l*>tt. 5. d s. d. 5. i. s. d. Ammonium Acetate, pure cryst. I 4 2 5 Carbonate extra pure — — 1 4 Chloride, pure — — I i 2 0 ,, Molybdate, extra pure — 2 3 4 4 6 7 Oxalate, extra pure — i 4 2 4 Sulpho-cyanide, extra pure cryst. — I 0 2 0 3 9 Aniline . . . . . . . . . . . . . . . . g.s.b — — i 8 3 o Azolitmin, extra pure 8 2 — — — Barium Chloride, extra pure — — — i 3 „ Oxide hydrated, extra pure cryst. — — — 1 7 Benzidin, for blood test 2 O 7 8 — Bromine, Reagent . . . . . . . . . . . . g.s.b. — 2 O 2 IO 5 4 Cadmium, Boro-tungstate Solution, 3.28 . . . . . . . . g.s.b. 2 5 9 ^ — Calcium Carbonate, precip., extra pure — i 5 2 8 „ Chloride, pure, dry gran. . . . . . . . . — — i 5 ,, ,, ,, fused white, lumps . . — — I 2 2 I ,, ,, granulated for drying tubes — — — I O Oxide, caustic (burnt lime) from marble — — — i 8 Phosphate, Acid . . — — I 10 3 5 ,, ,, Tribasic, dry — i 6 2 2 4 i Sulphate, pure precip. — — I 6 2 9 Charcoal, Blood, purified by acid . . — 2 5 4 7 9 * ,, Animal, extra pure dry . — 2 I 3 " 7 8 Cobalt Nitrate, pure . . . . . . . . . . . . g.s.b. i 3 4 ^ — ,, ,, extra pure, free from nickel . . . . . . . . g.s.b. 2 I 7 4 — — Copper Metal, extra pure by electrolysis — i 5 2 9 ,, Bichloride, pure — i 3 2 4 4 5 White Monochloride • — i 4 2 8 5 o ,, Oxide, wire form — I 0 I IO 3 & „ pure powder — — i 8 3 3 ,, Sulphate, extra pure cryst. — — — i 6 Cubes, for generating Sulphurous Acid — — — i 9 Dicyandiamidinsulphate Nickel . . . . . . . . . . g.s.b. I I 3 4 — Dimethylglyoxim 4 6 — — — Diphenylamine, extra pure, white cryst. — 2 2 4 4 7 i 5 10 25 gram. gram. gram. Furfurol, extra pure Reagent for testing Margarine B. Pt. 158-160°, in 5, 10 and 25 tube. tube. tube. gramme tubes 0 10 I 7 3 9 Per Per Per oz. 4 oz. 41b. bott. bott. bott. Glycerine, twice distilled, extra pure, 1.230 — — I 0 i ii Haematoxylin, cryst. 4 2 — — — Hydrazine Sulphate, extra pure 2 O 7 6 — — Indigo (from plants) 2 10 5 8 — Iodine resublimed, extra pure . . . . . . . . . . g.s.b. 1650 8 10 17 5 Reel of loo gram. Iron Metal Wire, 0.57 mm. 2 0 Reel Reel of 10 of 50 gram. gram. „ ,, fine 0616 Per Per oz. 4 oz. bott. bott. „ ,, Powder — . _ — i i „ Hydrogen reduced, extra pure . . I I 2 0 -(& 3 " A, iVtra InCHEMICAL AND SCIENTIFIC~APPARATUS AND PURE CHEMICALST If F VV II ^^ *J ^S\ /^^^^ 1197 BAIRD &.WLOCK (LONDON) LTD. Merck's Guaranteed Reagents (continued}. Per Per oz. 4 oz. bott. bott. s. d. s. (i. Iron Ammon. Sulphate, extra pure . . „ Sesquichloride, cryst. .... Lacmoid Scales, extra pure Lead Acetate, extra pure, Ph. Helv. IV. „ Peroxide, extra pure, free from Manganese Litmus, extra pure Magnesium Carbonate „ Chloride, extra pure Oxide (calcined Magnesia), free from Sulphuric Acid Manganese Peroxide, Pryolusite abt. 90% Mercury Metal, extra pure redistilled „ ,, in nickel bottle ,, Bichloride, extra pure Metadiamidobenzol Hydrochlor., pure (Phenylendiamine Hydrochlor.) . . Naphthylamin, alpha, extra pure Nitrophenol, ortho para Perhydrol (H2O.j chem. pure Merck = 100 volumes), original bottles in tins Phenolphthalein pure Phenylhydrazin, extra pure, in original g.s. bottles of 25, 50 and 100 grammes Phloroglucin, extra pure, free from Diresorcin Phloroglucinol, for wood pulp Potassium Antimoniate, pure ,, Bichromate extra pure cryst. ,, Bisulphate, ,, ,, Bromide, ,, ,, Chromate, yellow, extra pure ,, Cyanide, extra pure ,, Ferricyanide, extra pure Ferrocyanide ,, ,, ,, ,, powder Hydroxide, „ Iodide, Nitrite, Permanganate, pure cryst. extra pure, free from Sulphuric Acid ,, Sulphate, extra pure cryst. Sulphocyanide, extra pure cryst. Potassium and Sodium Tartrate (Tartarus Natronatus) Resorcin, resublimed, perfectly white Silver Nitrate, extra pure cryst. ,, Nitrite, extra pure Sodium Biborate Bicarbonate, extra pure powd. Carbonate, chem. pure anhyd. Chloride, chem. pure >, ,, extra pure, fused Per Jib. bott. s. d. — , — I O I O i 96 7 13 o 2243 i i 3 ii ; 7 8 — r 5 10 2 II 56 g.s.b. — i ii 3 3 — i 8 3 2 g.s.b. g.s.b. 2 0 2 0 I 2 I 2 7 8 7 8 3 10 3 10 15 0 15 0 7 4 7 4 5° 200 gram. 3 o Per gram. 9 6 Per oz. bott. 4 oz. bott. . . I 2 4 4 8 4 25 5° loo gram. gram. gram. I 2 Per 2 0 Per 3 8 Per oz. bott. 4 oz. bott. Jib. bott. . . 12 II — — . g.s.b i 8 5 8 i 6 II 2 * * — I 8 — I 0 i 8 g.s.b. I I i 5 6 6 2 8 — • — 1 4 . . — I 0 I 10 :: i 3 T "3 4 6 2 5 7 8 — I 0 2 0 — — I O — — i 8 . . — i 8 3 4 — — i 3 g.s.b. g.s.b. i 5 2 IO 7 8 5 4 10 4 10 10 — — i 3 CROSS STREET • HATTOTsT GARDEN. E- C BAIRD &.TATLOCK (LOM)ON) LTD. Merck's Guaranteed Reagents (continued}. Per IV, IV, Per. oz. 40Z. lb. ilb. bott. bott. bott. bott. s. d. s. d. .-. rf. t. d. Sodium Hydroxide, extra pure from Sodium i 8 3 4 purified sticks — — 1 4 Hyposulphite (thio-sulphate), extra pure — — — 1 0 ,, Nitrite, extra pure, sticks — — i 5 2 7 ,, Nitro Prusside, cryst. i 8 6 2 12 4 „ Phosphate, extra pure cryst. — 3 3 6 o — Thymol, cryst. — 2 7 5 o — Tin Metal, pure granulated — i 4 2 7 5 r ,, Chloride, cryst., pure — i i 2 I 4 i Uranium Acetate, extra pure cryst., free from Sodium . . . . g.s.b. 2 9 IO 0 19 10 35 8 „ Nitrate, extra pure cryst. . . . . . . . . . . g.s.b. I 10 6 4 12 6 21 & Zinc Metal, free from Arsenic, granulated — 1 7 „ ,, „ thin sticks — — I I 2 O ,, ,, ,, ,, coarse powd. — — i 3 2 4 filings (in parcels] . . . . .'. — — i 6 3 o highly pure, powder . . — — i 5 2 & ,, chem. pure, granulated — I 0 I 10 3 7 ,, ,, „ thick sticks — I 0 I 10 3 7 ,, Chloride, pure dry — — — I 2 jnCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &_ 1ATLOCK (LONDON) LTD. Price List of Chemicals and Reagents, PRICES SUBJECT TO MARKET FLUCTUATIONS. SPECIAL QUOTATIONS FOR LARGE QUANTITIES ON APPLICATION. ivr ib. Per Ib. Per Ib. for for for Per oz. Perlb 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. 5. d. s. d. s. d. Acetamide o 9 9 o — — — Acetic Anhydride, extra pure o 4 3 6 — — — Acetone coml. i 3 — — W. Qt., i/i per Ib. rect., boiling pt. 56°-58° C. . . 0 2 i 7 — — — W. Qt., 1/5 per Ib. Acetyl Chloride o 3 2 9 2 8 — — . Acetanilide, extra pure white cryst. (Antifebrin) 0 2 i 5 — — — Acetonitril (Methyl Cyanide) 3 8 — — — Acetophenone (Hypnone) I 2 — — — — Acid, Acetic (B.P.) ,, ,, glacial, 50° F. 0 I o 4 o 8 — — — W. Qt., 3d. per Ib. , W. Qt yd. „ , = 5J Ibs. „ „ 60° F., 99 to 100% O I 0 II 0 10 — — „ ., specially cone, for Valenta test 0 3 3 o — — — Arsenic, pure, dry O 2 2 0 . — Arsenious, pure, powder . . 0 I I 0 — — — ,, sublimed lump . . 0 I I 0 — — — , ,, coml., powder 0 I o 6 — — Benzoic, pure, from gum i 5 17 o — — — ex toluol O 2 2 0 , Boracic, extra pure, cryst. 0 I o 7 — — — ,, ,, ,, powder 0 I o 8 — — — . coml., cryst. — o 4 — o 31 — Cwt., 317- ,, ,, ,, powder . . — 0 5 — 0 4J 35/- ,, Bromic, 1.12, free H2S04 o 9 9 6 ,, Butyric, puriss., normal, free from caproic and acetic acids i 8 ,, Butyric, pure, cone., 50 % 0 2 I 10 — - 100% o 4 4 ° , Carbazotic (Picric) 0 3 2 3 Carbolic, coml. o 6 loose crystal 0 2 1 3 I 2 I I Gallon, 2/9. i-lb. bottle included. " liquid.'B.P. ,, ,, absolute phenol. — I 2 — — — 28-lb. tins, 25/- each. Gallon, 1 1/6. No. i, Calvert's . . — 6 8 — 1 ,, 2, ,, 4 4 i-lb bottles included. Carminic, extra pure n 6 i i ,, Chloracetic, mono, pure cryst. . . o 3 3 o _ tri, pure cryst.. . o 6 6 o Chloric, pure, 1.12 o 3 3 o Chromic, coml. 0 I 0 II 0 10 pure, about 90% free H^SC^ (Reagent) . . Chrysophanic, medic. O 2 0 II I 10 4 3 II O 1 9 i 8 In i-lb. bottles (bottles extra) (bottles free). , ,. oxide 8 6 — CROSS STREET • HATTON GARDEN, E-C 1200 BAIRD&TATLOCK(LOM)ON)LTD. Price List of Chemicals and Reagents (continued). IVr Hi. ivi Ib. 1 Perlb. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. S. (/. s. d. s. d. Acid, Cinnamic, extra pure, medic. o 8 8 o — 7 7 — Citric, cryst. O 2 i 9 — i 8 ,, powder O 2 i ii — — I IO ,, ,, purif. free lead o 3 2 9 — — — Cresylic, pure o 4 3 3 — — — Formic, pure 1.2, about 85% CH202 O 2 i 6 — — — ,, „ ,, 1. 12, about 50% ,, 0 I 0 10 — — — „ 1.06 . . . . 0 I o 6 — — — Formic, pure 1.22, crystallisable o 4 3 6 — — — ,, Gallic, pure cryst., white (P.B.) . . 0 2 2 4 2 3 2 2 — Hippuric, cryst. 2 3 — — — Hydriodic, sp. gr. 1.50 i 3 15 0 — — — i 70 i 6 18 o ,, ,, ,, 2.00 2 0 24 o . . ,, Hydrobromic, pure cone, fuming 82% o 7 7 o — — — „ 1-49 - 48% o 4 3 6 — . — — Hydrochloric, coml., 1.16 O 2 — — — i W. Qt., ijd. per lb.\ Carboys, id. 1 12 W. Qts., ijd. ,, pure, 1. 16 — o 4 — — — f W. Qt., 3id. \ W. Qt. j Carboys, 3d. = 6 Ibs. ,, ,, puriss., redist. 1.16 — . o 6 1 12 W. Qts., 3jd. pure, 1.195 — . o 9 — . — . — W. Qt., 5d. ) , ,, pure, i.io, free from " arsenic O I I O ,, ,, freed from arsenic W. Qt., 6 Ibs. at gd. per Ib by special process o 3 2 6 — — . — Hydrocyanic (P.B.) — — — • — — i i-oz. blue bottles, 4d. each ; per doz. ' 3/6. Hydrofluoric, coml. redistilled . . 0 I o 3 0 10 2 0 — o 9 I IO o 8 1 9 1 Guttapercha bottle extra, not return- able, but can be refilled. * Lead bottles supplied to order. „ puriss., redist. free residue ,, Hydrofluosilicic, coml., 1.157 0 I o 9 — — — i In 4-oz. paraffin bottles, 2/6 each, i bots. included ; per doz. 277-. ,, lodic, pure cryst. 2 0 — — — - Lactic, ex. pure white 1.21, P.B. o 3 2 8 — 2 6 — ,, Lithic (uric) extra pure . . i 6 21 O — — — ,, Malic, pure cryst. 2 9 40 o — . — — Malonic i 5 19 6 _ — — ,, Meconic, cryst. 3 6 — — — . — Molybdic, pure o 8 8 o 7 10 7 9 7 8 ,, ,, about 100%, extra pure o 9 9 o — (Free Nitric Acid and Ammonia. ) Mucic, pure I 0 — — — — Nitric, coml. 1.42 — o 5 — — — i W. Qt., 4td. per Ib. } ( Carboys, 4d. pure, 1.42 . . — o 6 — . — . — 1 W. Qt., 5Jd. .. W. Qt. i Carboys, 5d. „ = 8 Ibs. i. 36 o s , W. Qt.. 4Jd. „ > u 0 ( Carboys, 4d. ,, puriss., redistilled, 1.42 — 0 10 — — — W. Qt., gd. - 8 Ibs. fuming, 1.50 — . i 6 — — — Nitrous, ,, 1.36 - o 7 — — — ,, Oleic, pale . . -wSSSN — o 8 o 7 =e?i5 x Per cwt., 567- -(Oe^ | /if-AT' ~J ^ \J l«»*\ / lilfjCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1] "ijsy:^^-- — y=^a^^je^jj^^ss^-^ —**~^-%sz*t>~ 1201 BAIR.D &TATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued). Acid, IVr 11). Per Ib. Per Ib. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. (i. 5. d. s. d. i. d. Oleic pure P.B o 7 7 o — — — Osmic i % solution 2 0 — — — — i gramme tubes — ,, 2% ,, 3 9 — — — — i 6 12 tubes. „ cryst — — — — 6/- 5/10 5/8 each. Oxalic, coml. 0 I o 5 — — 0 4i | gramme tubes — i 6 12 tubes. ,, extra pure, cryst. 0 2 i 3 — — I 2 3/3 3/2 3/1 each. „ anhydrous sublimed 2 O — — — — Palmatic, pure i 3 — — — — Perchloric, pure, 1.12 o 4 4 o 3 9 3 8 — Phosphomolybdic, cryst. 2 6 30 o — Phosphoric, ortho, syrupy 1.7 . . 0 2 i 3 — I 2 „ anhydrous extra white t In i 2 4 8 16 oz. bot. powder t — yd. lod. 1/6 2/6 3/6 each. meta, glacial sticks . . Phosphorous, 1.12 o 3 o 4 2 3 3 6 — 2 2 2 0 'j (Stoppd. bots. included in above 1 prices.) ,, cryst. i 6 20 0 — — — Phosphotungstic, ex. pure cryst. I 2 14 o — — — Phthalic, pure cryst. o 8 8 o — — — ,, anhydrous o 4 3 6 — — Picric (carbazotic) o 3 2 3 -— — — Propionic, extra pure i 8 — — v — — i Per Ib., gd. perjoz. Pyrogallic (Schering's) sublimed 0 10 — — — — -1 50 oz. lots at 8Jd. | i oz. bottles free. „ (Merck's) sublimed . . O II — — — i oz. tins. See page 1245. heavy cryst. o 9 — — — — Racemic (Uvic) 7 6 — — — — Rosolic o 5 4 6 — — Salicylic, natural . . i 6 — — — (Fm Wintergreen oil.) „ amorphous, P.G.V. 0 2 i 8 i 7 — i 6 „ P. B. cryst 0 2 I 10 1 9 — i 8 Salicyl-sulphonic 0 10 9 6 — Selenic, pure, 1.40 9 6 Silicic, pure, precip. (Silica) 0 2 2 0 — Stearic coml. O I O IO O O o 8 extra pure, P.J. III. i 6 17 6 w y Succinic, pure white cryst. i 6 20 0 Sulphanilic, white cryst. o 5 4 6 , Sulphindigotic, solution O 2 i 6 Sulphomolybdic i 6 18 o Sulphuric, anhydrous, specimen in sealed bulb, containing about 8oz., 5/6 each. Sulphuric, coml., 1.84 _ 0 2\ (W. Qt., 2d. perlb. . Carboys, id. „ W. Qt. 12 W. Qts., ijd. ., I -10 Ibs. „ pure, 1.84 — o 4 — — — /W. Qt., sjd. „ (Carboys, 3d. ,, ,, I.2IO ,, free from arsenic O I o 4 I 0 — — W. Qt., 3 Id. per Ib. , w Qf W. Ot., lod jo Ibs ,. ,, ,, nitrogen o 7 W. Ot , 6d ) „ Xordhausen I 0 Sulphurous, solution — o 3 anhydrous, in syphons i 8 i Syphon, 6/6 extra ; J allowed when c returned Sulphurous Tannic, light, pure o 4 3 o i _ — 12 oz. tubes, 1/3 each. 1202 BAIRD &TATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued). IVr Hi IVr Hi IVr 11, for for for , Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. *. /7>^ JCHEMICAL AND SCIENTIFICAPPARATUS AND PURE CHEMICALS-]^ 1203 4H Wf) BAIRD & TATLOCK (LOM)ON) LTD. JlMI Price List of Chemicals and Reagents (continued). Perlb. for Per Ib. for Perlb. for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. 5. d. s. d. s. d. s. d. Aluminium, Leaves, per book, 6d. — — — — — ,, Powder, coarse o 5 4 6 — — — ., ,, fine o 6 6 o 5 6 . — — Sheet o 4 4 o — — Wire — — — '1° -" 20 30 U.W.t,. , Acetate, dry basic 0 2 i 6 — . — — ' iod. lod. i/- i/- per oz. „ Bifluoride o 9 9 o — — — Chloride, cone, solution . . O I I 0 — — — pure crystal o 3 2 6 — .._ — ,, ,, anhydrous, sublimed o 4 3 8 — — — (Smallest quantity sold, 2 oz.) ,, Nitrate, cryst. 0 2 i 3 — — — Oxide, extra pure, free alkali o 4 4 o — — — ,, ,, hydrate, pure . . o 2 2 O — . — — ,, ,, ,, coml. . . o i o 9 o 8 o 7 — ,, precip. moist . . : — i 3 — — — (Moist Alumina.) „ Phosphate o 4 3 4 — — — ,, Sulphate, pure 0 I o 8 o 7 o 6 — ,, „ extra pure, cryst. 0 2 2 3 I 10 — ,. Sulphocyanide solution 1.16 0 2 I 0 — Amalgam, Electrical o 6 6 o ,, Sodium o 7 6 6 Amber Cuttings and Chips 0 2 2 0 Amidol (Hauff) _ i-oz. bottle, i/io ; 16 oz., 1/9 per oz. Ammonium, Acetate, crystal, pure . . i o 2 i 8 1 7 i 6 — ,, cone. sol. • • ! o i o 8 Arsenate, cryst. o 4 4 o Arsenite o 4 3 9 . Benzoate, from gum o 7 «-* »/ 7 o Bicarbonate, cryst., pure 0 2 i 6 Bichromate, extra pure cryst. 0 2 2 0 — „ Bifluoride 0 3 2 9 2 8 Bimalate 4 ° J Bisulphite o 4 4 ^ — — ,, solution 0 I 0 IO o 9 — „ crystal, pure o 9 9 ° — Bitartrate o 4 4 ° Borate, pure o 4 3 4 ,, Bromide Carbonate o 3 0 I ^ i o 5 2 10 2 9 o 4! — j i4-lb. tins, i/- each extra, not returnable. ,, extra pure . . 0 I I O 0 II \ Chloride, pure . . ..to i O 10 o 9 o 8 powd. (sal- ammoniac) O I o 7 — — o 6 Per cwt., 50;-. lumps . . oi o 6 O ^ » ,, compressed Chromate, pure, neutral 0 5 4 6 • — — w D i " Voltoids " for recharging Batteries, See page 1240. ,, Citrate o "5 6 „ Ferrocyanide, pure *J O 10 T- \s 10 O Fluoride, purif., free As o 2 2 0 . I 10 .» extra pure . . 07 7 0 Formate, pure . . . . 0 6 / 6 o s^sas •ftesx- -vetJ3» /lE^u. ffLJ^'.CR-oss STREET • HATTOlSf GARDETST, E-C- ]f]j 1204 BAIRD &. TATLOCK. (LOTsTDON) LTD. Price List of Chemicals and Reagents (continued). Per 11,. Per 11,. Per Ib. for for for Peroz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d s. d. i d s d Ammonium, Hippurate Hydrate, .880 . . „ .880 free from 3 6 0 I o 6 (W. Qt. 5d. perlb. |W. Qt. j 12 w. Qts., 4id. „ [-Vfn* tar products , Hypophosphite . . 0 I 0 10 I 0 10 0 — — — 1 W. Qt. W. Qt., lod. „ { = 4J Ibs. ,, Hyposulphite, pure cryst. o 4 3 6 — — — ,, Iodide, pure i 4 16 o — — — „ Lactate o 7 6 6 — — — Malate 4 ° — — — — „ Metabisulphite . . o 5 4 6 — — — ,, Molybdate, pure o 7 7 o 6 10 6 9 — ,, Nitrate, coml. cryst. 0 I o 8 o 7 o 6 — ., ,, extra pure, cryst. 0 2 i 3 I 2 i i — ,, „ pure, fused 0 2 1 9 — — — Nitrite, solution 0 3 2 6 — — — * Oxalate, extra pure 0 2 i 8 1 7 — i 6 ,, Persulphate o 3 2 3 — — ,, Phosphate, extra pure . . o 3 2 3 — — — ., Phosphite i 3 15 0 — — — Phosphomolybdate 2 0 24 o — — — ,, Picrocarminate . . 2 6 — — — ,, Salicylate, cryst. o 7 7 o — — . — „ Silicofluoride o 7 7 ° — — — ,, Soda phosph. (microcos- mic salt) extra pure 0 2 i 6 i 5 . — i 4 ,, Stearate . . i 3 15 0 — ,, Succinate, cryst., pure . . I IO 22 0 — — — ,, Sulphate, coml. — 0 4 o 3i o 3 — Cwt., 22/-. * recryst. 0 I o 6 o 5 — Cwt., 4O/-. ,, ,, extra pure 0 I o 9 — o 8 o 7 Sulphide, sol., extra strong ,, Sulphite, pure, cryst. . . o 3 o 8 3 o — — (W. Qt W. Qt., 7d. per Ib. - _ £ ,bs ,. Sulphocyanide, coml. . . 0 2 I 2 — i i — ,, „ pure cryst. 0 2 i 6 i 5 i 4 — ,, Tannate 0 8 8 o — Tartrate, neutral cryst. . . o 4 3 6 — — — Urate, pure I 10 — — — ,, Valerianate, cryst., white o 7 6 6 — — — Vanadate i 6 — — — . — Amygdaline 2 9 — — — — .\rnyl, Acetate coml. specially pure o 3 o 5 2 6 4 6 — — — W. Qts., 2/4 per Ib. Butyrate . . o 4 4 o — — — ,, Iodide, B.Pt., 140° to 148° C. . . i 6 20 0 — — — „ Nitrate o 8 8 o — — — „ Nitrite, P.B o 5 4 9 — — — ,, Valerianate, pure I 0 12 0 — — — \niline Oil, crude 0 I I O — — — ,, ,, extra pure . . 0 2 i 6 i 5 i 4 — „ Acetate . . o 5 5 o — ,. Hydrochlor., pure cryst. O 2 i 6 — — . — Nitrate o 6 6 o — — — Phosphate o 4 4 o — — — ,, Sulphate gw<£53tS— i o 3 2 3 '-"* *'-^» Brassy ^^ fJCHEMICAL AND SCIEN' PIFIC E=^ APE 533^s£ \RAT 8^*g3 us; ^^= IND] PURE CHEMICALS.JQlj 1205 BA1R.D &TATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued). Per Ib. Per Ib. Per Ib. for for tor Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s d s d 5. d. ? d s. d. Aniline Colours, for dyeing experi- ments, &c. (not suitable for microscopic work) — Aurantine 0 10 9 o — — — Aurine 0 6 6 o . — — — Black 0 6 6 o — — — Bleu de Lyon I 0 12 O — — Blue, methyl I 0 12 0 — — — , Hoffmann's 2 0 — — — — , methylene , gentian . . , Nicholson's I 0 i 4 1 4 12 O 14 o 16 o — — — See page 1189 for Gnibler's Stains for Microscopic Work. , soluble I 3 — - — — — Brown, Bismarck o 4 3 6 — — — „ Blackley o 10 IO O — — — Vesuvian, dark o 6 3 6 — — — Chrysoidine, light o 9 7 6 — — — Ccerulin, paste . . I 0 — — — S i 6 Congo red o 6 6 o — — — Coralline o 6 5 o — — — Dahlia o 9 9 6 — — — Eosine blue shade o 8 7 6 — — — ,. yellow shade o 9 8 6 — — — Erythrosine I O 12 0 — — Flamingo I 0 — — Fluorescine 0 IO IO O — — Fuchsine, purif. 0 10 8 o — — — „ acid I 0 — — — — Green conc'd (acid) I 0 IO O ,, iodine 1 9 20 0 ,, malachite, opt . . o 8 7 6 „ methyl i 6 16 6 , Induline o 6 5 6 See page 1189 for Grtibler's Magenta, acid Maroon Mauve 0 10 o 6 2 0 IO O 6 o — — Aniline Dyes' for Microscopic Work. Naphthol blue i 6 Night blue I 0 12 6 ^ Nigrosine o 6 6 o Orange I 0 12 O methyl I 0 12 0 Phloxin i 4 Phosphine 2 3 Ponceau o 9 7 o Primrose I 0 / Primuline o 9 6 6 Purpurine I 0 12 0 Purple (Spiller's) . . . . '.'. 2 0 \ Rosaniline i 3 — ,, acetate I 0 12 O hydrochlorate (fuchsine) . . 0 10 no o _ __ „ nitrate (rubine) 0 10 to o . oxalate 3 o sulphate i 9 — — — — 1206 BAIRD &TATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued). Per ib. Per Ib. IVr II,. for for for Per oz. Per 11). 7 Ibs. 14 Ibs. 28 Ibs. 1. d. i. d. 1. 0 8 8 o •sz^ss •^ZSEx f5t3S /£^x_ ilO 14 • CROSS STREET • HATTOTJ GARDEN, E- C 1208 BAIRD & TATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued). IVr 11.. Per Ib. IVr 11.. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d s. d. s. d. s. d. s. d. Benzoyl, Chloride, pure o 4 4 o Benzyl Bichloride (benzal-chloride) . . o 3 2 6 — — — Bismuth, Metallic 0 10 ro o — — — extra pure i 3 15 0 — — — granulated, free from Arsenic I 2 14 o — — — ,, Carbonate (P.B.), ex. pure . . 0 10 10 6 — — — „ Chloride, cryst. I I 13 o — — — „ ,, oxy (subchloride) I I 13 o — — — „ . Nitrate, crystal o 7 7 o — — — „ sub (trisnitrate) extra pure o 9 9 o — — Oxide, hydrate, pure i 4 16 o — — — Sulphate i i 13 o — — — Black Flux from cream of tartar . . ' o 4 3 8 — — — Bleaching Powder — • — — — — * i-lb. tins, 5<1. each ; 7 Ibs., 4jd. Ib. Blood Fibrin o 8 8 o — — — Bone Ash for assaying, best — o 4 — o 3 — Cwt., 25/-\ Borax, Crystal (sodium biborate) 0 I o 4 — o 3 — Cwt., 22/- ,, Ground . . 0 I o 4 — o 3 — Cwt., 243. „ Pure, Powder 0 I I 0 0 IO o 9 o 8 Special prices tor V cwt. tin-lined cases (or ,, Pure cryst. 0 I 0 II o 9 o 8 — export. Dried, for assaying 0 I o 8 — o 7 o 6 Cwt., so/- Fused, glass lumps O I o 8 — o 7 — Cwt., s6/- „ ,, ,, powdered O I o 9 — o 8 — Cwt., 6o/- Boron, Crystal, per grm., 8/6 • Bromine o 6 3 4 — — 1 Original bottles, 2/11 per Ib. (weight 1 8J Ibs. nett.) ,, Free sulphur o 7 6 o — — - — Tubes, 2.2 c.c. (for Urine Ana- lysis), (in boxes of i doz.), ,o 6 12 doz. 2/10 per doz. — — — — — j j \ 2/9 2/8 2/0 per doz IBromoform, Pure o 6 5 6 — • — — • Bromonaphthaline O 10 10 0 — — — Brucine, Pure crystal . . 2 O — • — — — ,, Sulphate 2 3 — — • — • — Butyl Acetate, iso, extra pure . . o 8 7 6 — • — — ,, Iodide, iso 5 o — — — • ^— Cadmium, Metallic, sticks o 5 5 6 5 3 — . — ., Metal, ribbon o 7 7 6 — • — • ., „ powder o 9 8 6 — — — „ Acetate o 8 7 & — — • — ,, Borotungstate solution, sp. gr- 3-28 i 8 24 o — — • — ,, Bromide, crystal o 4 4 6 — — • — 1.. Carbonate, extra pure o 7 7 o — — — ,, Chloride, pure o 7 7 o — — • — ,, Iodide i 6 • — • — — • — ,, Nitrate o 5 5 o — — — ,, Oxide, anhydrous I 0 12 O • - — - — „ Hydrate, pure O IO 9 6 — — — ,, Sulphate, pure o 6 5 6 — - — — ,, Sulphide, orange o 7 7 o — — — ,, Sulphite, extra pure ! Caesium Metal by electrolysis I 0 12 O — — . — . (20/-per grm., in .1, .5, or i.o grm. tubes only. ! Caffeine, Pure . . i 3 — • — • — — ,, Hydrochlor I 0 — ' — • — • — Price List of Chemicals and Reagents Per Ib. Per Ib. Per ID. for for for Peroz. Perlb. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. s. d. s. sible 0 I o 6 it" rlp- — o 4 — — — 1 LIC Soils s . . o 5 5 o — — — o 3 — — — r . . 0 I o 8 — — — o 3 2 6 — — — 0 2 i 3 I 2 I I I 0 2 0 — — — — I 6 — — — — ) -. i 6 — — — — O 2 i 4 — — o 3 — — — — o 3 — — — — o 3 3 o — — — — i 6 — — 0 2 2 0 — z z 6. o 5 4 6 _ _ _ o 7 6 6 — — — o 5 5 o — — — . . 2 3 — — — — , . 0 2 i 6 — — — o 6 6 o — — — irous 9 o — — — — . . o 8 8 o — — — . . — o 4 o 3 O 2\ O 2 o rVio o 4 3 6 — — 11 1 >' 1 rnis) o 9 9 Q — — — — o 4 — — — — o 4 — — — — • o 5 — o 4^ o 4 o 4 3 6 — — , — o 3 2 6 — — ; — O I I 0 — — — Prices variable. Made from dried balsam Per doz. tubes, 8/6. See also Saccharose. W. t., 6d. per Ib. i W. Qt. i/i" , i = 7 Ibs In i-oz. tins, in water. For i 8 1 Per oz. 3/3 3/2 i oz. tablets' in tins. For i 8 'Peroz. 3/4 3/1 4-oz. bottle, 5/- .. 3/6. 16 oz 16 oz. 2/10. Per dozen bottles, 5/9. Per cwt.. i8/- CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALSJj) 1211 BAIRD &. TATLOCK (LOM)ON) LTD. Price List of Chemicals and Reagents (continued). Per Ib Per Ib. Per Ib for for for Peroz Per Ib. 7 Ibs. 14 Ibs. 28 Ibs s. d. s. d. s. d s. d. 5. d. Chloroform, Methylated, pure 0 2 I 10 — — — W. Qt., 8 Ibs., 1/9 per Ib. „ Pure, from alcohol o 7 6 6 — • — — .- 6/3 „ Duncan & Flock- f i 1 Jib. bottles. hart's — — • — — — 6/8 3/5 ||i/io „ ,, from chloral o 8 8 o — — . — I (Bottles included.) Cholesterine 16 o — — — — Chromium, Metallic, cryst., per grm., 1/3 fused I O 12 O — — — . ,, Acetate, dry o 6 5 6 — . — — , Carbonate . . o 5 5 o — — — , Chloride, oxy i 6 19 o — . — — „ dry, pure o 4 3 6 — . — — , ,, sesqui., sublimed 2 6 — — — — ,, „ solution, 1.44 o 4 4 o — — — , Nitrate o 6 5 o — — . — , Oxalate o 5 5 o — . — — , Oxide, anhydrous, green o 3 3 o — — — ,, hydrated . . o 3 2 6 — — — ,, ,, extra pure o 4 4 o — — — ,, Phosphate o 5 4 6 — — — ,, Sulphate, scales . . o 3 3 o — . — . — ,, Sulphide 3 6 — Cinchonine, Pure, cryst. I 0 Hydrochlor, cryst. o 8 8 o — ,, Sulphate o 7 7 o — . Cinchonidine, Pure, cryst. 2 0 . . Cobalt, Metallic, 98 to 99 %, cubes . . I 2 14 o — . Acetate, crystal 0 8 7 6 — . . Carbonate, pure O IO 0 0 . Chloride, ,, 0 3 3 o Cyanide i 8 . Iodide 2 9 . Nitrate, pure, cryst. 0 3 3 o Oxalate, pure o 8 8 o . . Oxide, coml. black o 7 7 o — — extra pure 1 3 r5 o Phosphate i i 13 o Sulphate 0 3 2 6 Cocaine, Pure, cryst 12 O . Hydrochlorate, pure, cryst. . . 10 6 . . . , Sulphate 17 o . . Cochineal Collargol Collodion (B.P.) . '. o 3 o 6 3 o 5 9 — — — Box 100 tubes each 15 grains, 35/- ,. 25 ,, „ 15 „ 9/6. io „ ,, 15 „ 3/9. Extra thick Flexile, methylated . . Copper, Filings o 7 0 2 o 3 •i " 6 o 2 0 2 6 — — — W. Qt., 5/6 per Ib. ,. 1/6 Foil, pure, .002 in. thick 0 3 O Precipitated «J o => ._; *> o Shavings *J 0 2 fcj 2 O Acetate, pure, cryst., neutral O 2 | 2 0 ,, coml. powder (verdigris) Ammonia, chloride 0 2 0 2 i 3 i 6 — I s I 4 sulphate . . 0 2 1 9 — .j T1 •^&? -~/i^.- •s=^s/^ Price List of Chemicals and Reagents (continued). Perlb. Perlb Perlb. for for for Perot. Perlb. 7 Ibs. 14 Ibs. 28 Ibs. i. d. t. d. \ t. d. \ t. d. I i. d. Copper, Arsenate 0 2 1 9 — „ Arsenite 0 2 19 — Bichloride, cryst., pure 0 2 i 6 — 15 ^_ Bromide 0 8 8 o - - „ Carbonate, pure 0 2 1 9 — — — „ „ extra pure o 3 3 o Chloride, oxy o 3 2 6 — Chlorate, pure, cryst. o 10 iio o — . Cyanide, pure . . o 5 4 6 — — — „ Formate, cr o 6 5 6 — Iodide .. 2 3 — — Nitrate, extra pure, cryst. 0 2 i 6 — — „ crystal, coml. 0 I I O — Oxide, pure from wire o 4 3 6 — _*. „ „ granular o 3 3 o — — i „ powder .. o 3 2 6 1524 coml., black O 2 i 3 — 12 Phosphate o 4 3 6 - — - Potassio, chlorate (Chertier's copper) 0 2 i 6 — chloride 0 2 2 0 — - - Subacetate (verdigris) 0 2 13 — Subchloride o s 46- Suboxide, pure, red . . o 4 4 o — „ ,, coml. O 2 i 6 — — Sulphate, pure, cryst. O I o 7 — o 6 Cwt., yy- extra pure, cryst. free iron 0 2 I 2 I I I O — - coml. cryst. 0 I o 4 — — o 3i Cwt 3V. pure anhydrous, powder O 2 I 10 1918 — Sulphide, precip. o 4 4 O - — — _ „ fused sticks o 3 2 6 — — — Tartrate o 4 3 9 — — — Cotton, Gun, soluble I 0 10 O — — — - Wool, ist quality, white O 2 2 O I 10 1 9 2nd „ white 0 2 i 6 I 5 — i 4 N -'.'•.. 3rd „ grey o i 1312 — i i „ absorbent — 1918 — 1 7 Cotton Wool, Coloured, suitable for plugging test tubes containing bac- teriological cultures, to distinguish the different cultures : — Red, Blue. Mauve, Pink, and Yellow . . 03 2 6 2423 — Cream of tartar . . . . . . ..02 i 3 12 i i Creosote from beech tar (P.B. . . 03 3 o 2 10 — — Crotonchloralhydrate (P.B.) .. .. i o 12 O — — Cupreine Sulphate — — . — — Per gramme. : Curare, per grm., 4/- — — — — Per lo-grm. bottle Dextrine . . . . . . . . . . o i 04 — o 3i Cwt. Extra pure, precip., by ale. . . 03 - , 2 2 Dextrose (Grape sugar) pure . . ..05 4 6 - Diamantine Polishing powder .. . . 2 6 — — — __ Diastase of Malt (malrine) . . . . 25 ^nCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICA1 BAIRD &TATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued} . Per lb Per lb. Per lb. for for for Peroz Per lb. 7 Ibs. 14 Ibs. 28 Ibs. i d v tl s d s. d. a. d. Didymium, Sulphate 15 0 \ oz., 2/6. Dimethylamidoazobenzol, extra pure 2 0 — — — — Dimethylaniline o 5 4 6 — — — Dimethylparaphenylenediamine, base 16 o — — — Per gramme, gd ,, Sulphate 13 0 — — — — Chlor-hydrate 12 6 — . — — — Dinitrobenzol, Pure, meta o 7 7 o — — — ,, Com!. 0 2 i 3 — — — Dinitrotoluol, Coml. 0 2 2 0 — 1 . — ,, Pure, cryst. o 6 6 o — — — Diogen — — — — . — Per oz. tin, 1/6. Diphenal — — — — — Per 3-oz. bottle, 1/6. Diphenylamine, Extra pure, white cryst. o 6 5 6 — — — ,, Sulphate, extra pure Dulcite 0 10 IO O — — — 'Per J £ i oz. bottle. Dutch Leaf, per book, 4d. ; I2/- 23/- 45/- per doz. books, 3/6 Eikonogen 0 II ii 6 _ _ _ Emery Paper, blue backed Erythrite 13 6 — — — — • < No. o oo ooo oooo 'Quire 2/- 2/- 2/- 2/- Ericolin Substance — . i oz. bottle, 4/6. Eserine (Physostigmin), per grm. 7/6 Sulphate, powd., „ 6/- Ether, Aceto acetic o 8 7 6 — — — Anhydrous, distilled over sodium o 4 4 o — — — W. Qt., 3/8 per lb. ,, Methylated, sp. gr. .730 0 2 i i — — W. Qt., 4 Ibs., i/- per lb. „ .725 0 2 1 3 — — — , Special ' prices in „ .722 0 2 i 4 — — • " x/3 .. drums ,, .720 0 2 i 5 — — — ,, 1/4 ,, (on appli- „ .717 0 2 I 10 ,, 1/8 , cation). „ Ozonic o 6 5 6 ,, Petroleum 0 2 i 6 W. Qt., 1/3 per lb. ,, Spirit, nitrous, 1.7 o 6 5 6 Sulphuric, sp. gr. .720, pure . . o 8 7 6 W. Qt., 4 Ibs., 7/4 per lb. Ethyl, Acetate (acetic ether) B.P. o 7 6 o 5 6 Benzoate, from artificial acid . . o 8 8 o _ „ Bromide o 7 7 ° Butyrate (butyric ether) o 7 6 6 . Chloride, sol. 20 % o 8 8 o (Monochlorethane ) , lo-grm. tubes with straight points, ,, Iodide I 7 18 6 ' each 7d. ; per box of 5 tubes, 2/6. ,, Oxalate / O II II O (Enanthic 7 O Eugenol, Pure, soluble . . / 0 II II 0 — — . — • Farrant's Solution O 4 4 o Fehling's T^ O 3 3 ° Ferro- manganese, 80 % +J O I I O Fluor Spar (calcium fluoride) powd. 0 I 0 4 0 3 lumps 0 I o 3 O 2 Flux, Black, from cream of tartar o 4 •J T. 8 Formaline (formaldehyde), 40 % 3 u (Schering's) — — — — . See page 1194. 1214 H WIT BAIR.D &TATLOCK (LONDON) LTD. liUM •^ I .JBMM^M^M •*>>• •^^••••gi milk J_,> Price List of Chemicals and Reagents (fotitinutd). Per Ib. Per Hi. Pur Hi. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. s. d. s. . Gelatine Sheets . . 0 2 i 8 „ Best " gold label," Swiss — 2 6 2 5 2 4 — Coignet „ extra fine . . — 3 o 2 9 2 8 — ,, ,, ,, fine . . • 2 6 I Glass Balls, solid, clear Beads, small ) — 1 9 i 8 — — i 3 to 4 mm. diam., per Ib., 3 <>. 1 8 to 10 mm. diam., per Ib., 3 3. ,, ,, medium \ Clear glass- — i 6 i 4 — — „ large ) ( .. — 1 4 i 3 — — Blue O 2 2 0 — i Glass Beads, Green 0 2 2 0 „ Pink 0 3 2 6 — — — „ Red o 3 3 o — . — — ,, Turquoise 0 2 2 0 — . — — „ YeUow 0 2 2 0 — — ,, Powdered . . o 3 — — — ,, Wool, free from lead o 9 9 o 8 6 — — I Glucose (Grape Sugar), lumps O I o 4 . — — — ,, Pure 0 5 4 6 — — — Glue, Hollis — — . — Per bottle, 6d. ; per doz. 5/9. Le Page's fish — — . . — — — Per bottle, 6d. Gluten, Pure (vegetable glue) 6 6 — — — — Glutin, Animal o 6 5 6 — — — Glycerine, Price's pure, redistilled 1.26 0 2 I IO — — — W. Qt., 1/9 per Ib. , W. Qt. ,, Pure, 1.26 0 2 i 3 — — — „ 1/2 ,, 7 Ibs. Chemically pure, in 20 c.c. bottles, per bottle, 8d. (Grubler's). ,, Coml. brown — 0 II — . — . — W. Qt., 7 Ib., lod. per Ib. Jelly in 20 grm. bottles, per bot., i/- ; per doz., n/- (Griibler's). Glycogen, per grm., 2/6 Glycin, Hauff's, per oz. bottle 2 0 — . — — — Gold Capsule 130 o — — — — ,, Chemically pure, per grain, 4d. per drm., 6/6 ,, Leaf, per book, 1/8 — — — — — . Per dozen books, it)/-. „ Chloride, 15 gr. tube, i/io CV=«SL«- -~7~^SSX ^BflGC^^c ;x— tfff fe i For 123 doz. tubes, 21/6 2 1/- 20/6 per doz. S&S^ In CHEMICAL AND SCIENTIFIC^APPARATUS AND PURE CHEMICALS. Hi P/_». II W *A — j\ JL • i?i s BAIRD &L TXTLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued]. Per Ib. Per Ib. Per Ib. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. s. d. 5. d. s. d. Gold Chloride, 7$ grain tubes, each i/i — — — — . — (For 123 doz. tubes. 12/6 12/3 "/- per doz. „ „ solution, i % ,, „ and Soda o 9 28 o — — — — (In ij-grain tubes, 1/2 each; per ( doz., 12/6. ,, Cyanide 105 o — — — — ,, Iodide 52 o — • — — — • ftpig^ „ Oxide I2O O — — • — — f~jj Graphite (see Plumbago]. Grease for stopcocks, etc. (special mixture) Iln collapsible tubes, *•=- — =ML*^J| per tube i/-, per ^""""^Tl t\r>? TT'- Tn rj-o7 -i H Gum Acacia — bottles, each 4/9. : „ Finest white selected o 3 3 o — — — S oui U White 0 2 2 0 — — — 3 O (/) :J Coml 0 I I 0 — — — •- DlS -I! Mucilage, B.P o 4 4 o — — — Q ° "• §1] Benzoin o 5 5 6 — — — < 10 vol. O 2 1 9 — ,, Peroxide, solution, free Ba & H2SO4 or H3PO4, 20 vol. o 3 2 6 __ „ Peroxide, chem. pure, 100 %, by volume (Perhydrol) Hydroquinone, Extra pure 0 4 3 9 — — 50 200 grm. bottles. 2/6 7/6 each. Hydroxylamin Hydrochloride, extra pure 2 3 30 o — „ Sulphate 1 4 16 o Iceland Spar, selected pieces . . 0 10 10 0 „ coml 0 5 4 6 Indiarubber Solution J | i Ib. tins. i/3 z/- 3/6 each. Indian Ink (Chin-Chin) — . Per bottle, i/-. Indigo, Coml 0660 — 1216 BAIR.D &TATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (.ontinued) . L'cr Ib. JVr II.. 1'cr 11.. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. s. d. 5. d. s. d. Indigo, Purif., la o 9 9 o — — — Carmine, dry I 0 12 0 — — — ,, ,, paste, best o 3 3 ° — — — Sulphate, pure, dry (sodium indigo sulphate) 3 6 — — — — solution O 2 i 4 — — — Indigotine, Pure, crystal 7 6 — — — — Indol, cryst. scales — — — — — Per gramme, 1 1/-. Inosite — — — — — Per gramme, 7/6. Inuline, White (Alant Starch) . . i 4 — — — — Iodine, Resublimed I 2 14 o — — — ,, Coml. I 0 12 0 — — — Chloride (Mono-) i 6 — — — — „ (Tri-) I IO — — — — „ Tincture o 8 8 o • — • — -*• lodoform, Pure, crystal i 4 16 o • — — — Precip i 4 16 o — — — Iridium, Black . . — — — — — Per gramme, 14/6. ,, Chloride — — - — — — 7/-. ,, Sesqui-oxide — — — — — 16/6. Iron, Wire, pure, per bobbin, 6d. . . „ ,, for burning in oxygen, per coil, 2d. ,, Filings, fine — . o 6 . — 0 4 — „ Reduced by hydrogen, pure 75/80% 0 2 2 O — — , Rust — o 6 — — — , Acetate, dry o 4 3 6 — . — — , ,, per, scales, soluble o 8 7 6 — — — , Ammonia, citrate, brown scales o 3 3 ° — — — , ,, ,, green scales . . o 3 3 o . — — — - , ,, . chloride, proto O 2 i 3 I 2 — — , ,, sulphate, ,, cryst. . . O I o 6 — — o 5 , Arsenate (P.B.) o 3 2 6 — — — , Arsenite o 3 3 o — • — , Benzoate o 7 7 o — — — , Bromide, pure o 4 3 6 — — — , Carbonate, red 0 I o 8 — — — „ saccharated (P.B.) . . O I I O — — — , Chromate, liquid . . o 3 3 o — — — , Citrate o 3 3 o — — — , Ferrocyanide (Prussian blue) o 3 3 o — — — „ (soluble) o 4 4 o — . — — , Hypophosphite o 6 6 o — — — , lodatt i 6 18 o — . — — , Iodide, cryst. I 2 14 o — — — . Lactate, powder, pure 0 2 2 3 — — — „ crystal, pure 0 2 2 3 — — — Magneto, oxide, pure 0 2 2 O — — — Magnetic ore (attractable) o 4 3 6 — — — Malate 2 9 — — — — Oxide, pure, brown (P.B.) o 3 2 6 — — — „ com! 0 I o 6 — — — Percbloride, cryst., free HN03 . . O I o 9 o 8 — o 7 Pernitrate, cryst. 0 2 2 0 — — — solution, 33$% m*^£$\ e 0 I ^f&*-~7 I O •^**^a jgZSSTx rffifra iifjCHEMICAL AND SCIEN1 :IFIC V "APP; ^RAT us* JNDI >URE CHEMICALS-JQiJ w cj^ i^L^— ^^RSSfci 1217 BAIRD &TXTLOCK (LOM)ON) LTD. Price List of Chemicals and Reagents (continued]. Per Ib. Per Ib. Per Ib. for ior for Per oz. Per Ib. Tibs. 14 Ibs. 28 Ibs. s. d. s. d. s. d. s. d. s. d Iron, Peroxalate, scales . . o 5 4 6 — — — ,, Peroxide 0 I O 10 - — — — pure O 2 i 6 — — — ,, Persulphate, pure . . O I I 0 . — . — — ,, Phosphate, per, white O 2 2 O — — — „ proto, blue 0 2 i 6 — — • — „ Phosphide, pure . . 2 0 — — — — ,, Protochloride 0 2 I 2 — — — „ Protosulphate, puriss. O I o 4 . — o 3 — pure recryst. o 3 — — — ., Protoxalate 0 2 i 6 — — — ,, Succinate . . i 3 15 0 — — — ,, Sulphide thin plates o 4 — o 3 0 2i Cwt., i8/-. ,, ,, fused, sticks — o 6 — 0 5 o 4! .. 36/-- ,, Tannate o 4 3 6 — „ Valerianate o 7 7 o — — — Isatine . . 20 0 — Isinglass . . I 0 12 0 . — Izal — — — See page 1195. Jeyes' Fluid — — — — . — See pages 1194 & 1195. Kaolin, Purified . . 0 I o 6 — 0 5 Kermes Mineral 0 3 3 o — . — Kerol . _ , See page 1194. Kieselguhr, white, for filtering — o 6 — 0 5 La cm oid, Pure, scales i 6 — , Lactose (Sugar of Milk), powder 0 I O IO o 9 o 8 ,, powder, P.G.V. (Merck's) 0 2 i 6 — pure, cryst. (Grubler's) o 7 7 o Lanolin, Anhydrous (Dartring) o 4 3 8 Lanoline (Adeps Lance) i 3 . _ Lanthanum Sulphate 16 6 . Lead Bowls for determination of gold in cyanide solutions — • — — — JPer tin of 100, per tin of 25, I 10/6. 3/-. Lead Foil, pure, for assaying, free silver — o 8 o 7* o 7 o 6 Cwt., 52/-. ,, Grain, fine, for assaying, free silver 0 I 0 10 o 9 o 8 Cwt., 63/-. ,, Granulated 0 I o 8 0 7-J- o 7 „ 6o/-. „ Shot o 6 / £. / ,, Sticks for assaying 0 2 i 4 ,, Acetate, extra pure, cryst. 0 I 0 10 o 9 o 8 o 7 ,, ,, coml. O I 0 fi 0£ ,, „ tribasic cryst. . . 0 5 \J \J 5 o D o 4 ,, Arsenate o 3 3 o _ ,, Bichromate, extra pure . . 2 9 J ,, Borate 0 2 2 0 ,, Bromide . . . . . . ' o 5 5 o „ Bromate i 4 •J 16 o ,, Carbonate, extra pure 0 2 i 9 ,, Chlorate I 0 2 0 ,, Chloride, pure 0 2 I T. ,, Chromate, pure, fused, gran. o 3 kJ 2 3 _ ». ., „ powder . . 0 3 2 3 — — .. „ precip. 0 2 i 8 ,, Citrate o ^ 4 6 ,, Cyanide +J o 6 I V 6 o „ Formate, pure cryst o 7 7 o — — — jTl 14 -CROSS STREET • HATTOlsf GARDEN, E- C- (r|| 1218 BAIRJD &L lATLOCK. (LOM)ON) LTD. Price List of Chemicals and Reagents (continued). IV] Ib. IVl III. IV, II,. for for (or Per oz. Per Ib. 7 Ibs. i4lbs. 28 II. s. d. s. d. s. d. s. d. s. d. Lead Iodide, powder (P.B.) O 10 IO O — ,, cryst. I 3 15 0 — _ — „ Malate 2 0 — ,, Nitrate, pure cryst. 0 I o 9 — o 8 ,, ,, coml. O I o 6 O *\ — (\wt if I ,, Oxalate o 3 2 6 v D L-wt., 45/-. ,, Oxide, pure, litharge, free silver o 8 o 7 o 6 0 5 Cwt.. 35/-. coml. litharge — o 6 o 5^ o 5 04 „ 28/-. . red (minium) 0 I o 6 o 5j o 5 04 „ 28/-. (litharge) flaked . . 0 I o 8 o 7 o 6 0 5 .. 35/-- ,, „ hydrate, pure o 3 2 6 — ,, Oxy-chloride o 4 4 o . — — ,, Peroxide, pure o 3 2 6 ^ 5 — — ,, ,, coml. 0 I O IO — — ,, Phosphate, pure . . o 3 3 o — — « ,, Plaster (plumbi emplasti) O 2 i 6 — — — ,, Sesqui-oxide I I 13 o — — — „ Sulphate, extra pure 0 2 i 6 i 5 1 4 — ,, Sulphide, by wet process 0 2 1 9 — ,, Sulphite o 4 3 6 — . — — „ Tannate, dry o 3 3 o — — — ,, Tartrate o 3 3 o — . — — ,, Test papers, per doz. books, is. 6d. Legumin Lemco, for making culture media Levulose Syrup for microscope use 4 6 I 0 — — — — I 4 8 16 oz. pots. 1 2/3 4/3 7/9 each- Levulose o 6 5 6 — — — Lime Cylinders, best quality, 35. per doz. ,, ,, in sealed tubes, 6s. per doz. Lithium Bichromate I O 12 O — . — . . — ,, Carbonate, pure o 5 4 6 — — — ,, Chloride o 6 6 o — — — Iodide I 0 12 0 — — — Nitrate . . o 8 8 o — — — ,, Oxide (caustic) I 0 12 0 — . — — „ Sulphate, cryst. o 5 4 9 — — — \ Litmus, Granular O I 0 IO o 9 o 8 — ,, Powder O 2 i 6 — — ,, ,, extra pure . . O II II 0 — — — ,, Books - — — . — . — — See page 1246 Logwood chips — 0 2 — _ — Lycopodium o 3 2 9 — — — Lysol — — — See page 1195. i Parcels 7 Ib. 14 Ib. 28 Ib. Mabor, Powder for making Cupels . . Magnesium Powder o 10 9 ° — — — Each 2/6 4/- 7/6 1 1 c\vt. kegs, 25/-. ,, Ribbon i 4 18 o — — — ,, Rod, about £ in. diameter I O 12 0 — — — Turnings i 4 18 o • — — — Wire I 2 15 0 — • — — ,, Acetate o 3 3 o — — — Ammon . , phosphate chem. pure o 4 3 6 — — — ,, ,, sulphate O 2 i 3 I 2 i i — ,, Benzoate . . m*S%SS\ «E o 5 T!A~-~rs 5 o "•-j'«- WXSS^— -^3TEa_ ff>** JOCHEMICALAND SCIENTIFIC^APPARATUS AND PURE CHEMICALS. HI " \ /L_ W , u _I\ «_« <8s3-i="»-<-* — f V7V!iB^Bai^^t^V*'.>J-~» — • i ' TVJJIJM 1219 BAIRJD & TATLOCK. (LONDON) LTD. Price List of Chemicals and Reagents (continued} . Perlb Per Ib. Perlb for for for Per oz. Perlb 7 Ibs. 14 Ibs. 28 Ibs s. d. s. d. s. d. s. d. s. d. Magnesium Borate o 3 2 6 — — — „ Bromide, pure cryst. o 6 6 6 — — — „ Carbonate, light . . 0 I o 8 o 7 — — „ reagent O I I 0 — — — heavy 0 I I 0 — — — „ Chloride, extra pure, cryst. 0 I o 8 o 7 o 6 — „ „ fused, pure O 2 i 4 — — „ Citrate, soluble o 3 3 o — — — „ Hypophosphite, pure o 9 9 ® — — — „ Hyposulphite, pure, cryst. o 4 3 6 — — — Iodide i 8 20 o — — — „ Mixture 0 2 2 O — — — „ Nitrate 0 2 i 6 — — — „ Oxalate o 3 3 o — — — , Oxide, light 0 2 i 3 — — — heavy o 3 2 6 — — — , „ „ free As o 4 4 ° — _ — , „ light, free As o 4 4 o _ — — , Phosphate, pure . . 0 2 2 0 — _ — , Sulphate, pure, dry 0 I o 6 o 5 o 4 — , „ extra pure, cryst. 0 I o 6 o 5 o 4 o 33 Cwt., 28/-. „ ,, coml. . . — . 0 2 0 if io/6. „ Sulphite, pure o 3 2 6 . »» *• vf "• „ Tartrate o 5 5 o . Maltose, Cryst i 6 18 o . „ Coml. (French) I 0 12 O _ Manganese, Metal, pure, fused o 6 6 o Acetate, pure 0 2 2 O Benzoate o 8 7 6 Borate 0 I I O Carbonate, extra pure O 2 i 9 . . Chloride, extra pure, cryst. O I I 0 — , Chromate o 7 7 o Dioxide, black, coml. o 3 — — 0 2 Cwt i6/- „ pure 0 3 2 6 — — „ granulated for batteries o 3 . O 2 Cwt i6/- Ferrocyanide o 4 4 o ' Hypophosphite, pure o 7 7 o . Iodide i 6 16 o Nitrate, pure o 4 3 6 Oxalate, pure 0 2 2 O Oxide, red o 3 3 o Phosphate, pure . . o 4 3 6 Sulphate, pure cryst. O 2 1 3 I 2 i i I O Sulphide, pure o 5 , Sulphite . . o 4 ~ 3 0 , Tartrate . . J .7 i Mannite 5 4 o Marble Chips I 2 14 o O I ~~ Cwt., 5/-. Marine Glue Menthol, Recryst. Mercury „ Pure redistilled „ Ammonium chloride 0 3 2 6 o 3 o 4 o 4 1 4 3 o 4 ^ 3 9 I 2 2 10 3 10 I 0 2 9 3 9 2 8 3 8 j75-lb. bottles, special price i on application. Prices variable according to the market. Latest prices on application. 1220 BAIRD &1ATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued) . I'.T 111. I't-r 11). IVr 11.. for for for Per oz. Perlb. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. s. d. s. d. s. d. Mercury Bichloride (corrosive subli- mate), powder 0 4 3 4 3 3 3 2 3 o (corrosive subli- i mate), cry st. o 3 3 3 3 i 3 o 2 IO m E ij Biniodide, red P. B. powder O IO 10 0 — B a Bisulphuret, black . . o 3 3 4 — — — 2 5 „ (red vermilion) o | powder o 4 3 6 — — — Carbonate, per o 9 9 o — — — S * „ proto o 9 9 o — — — ^ ° 5 ° Chromate o 6 6 o — — — " S Cyanide o 8 7 6 — — — a g « "E. ., Iodide, green . . O 10 10 0 — — — a °- „ Oxide, red o 4 3 8 3 7 3 6 — 1 I „ yellow . . o 4 4 o • — — — • s ,, „ proto, black o 7 6 6 — — — § Pernitrate o 4 3 4 — — — i Persulphate . . o 3 3 o — — , — ,, Protonitrate, cryst. o 4 3 4 — — — Phosphate, per o 8 8 o • — — — proto o 8 8 o — — — Protosulphate, grey, for batteries o 4 4 o — — — pure .. o 6 6 6 — — — Subchloride (calomel) o 4 3 4 3 3 3 2 — Sulphide (cinnabar) powder . . o 5 4 9 4 8 — — „ Sulphocyanide o 4 3 9 • — — — Metaphenylenediamine hydro-chloride 1 9 21 0 — — — Methylal, Pure o 6 6 o — — — Methyl, Acetate o 6 6 o — — — - Cyanide (acetonitril) . . 4 6 — — — — ,, Iodide i 6 — — — — Orange i 6 — - — — — Oxalate I 0 — — - — — ,, Salicylate, artificial Metol (Hauff's) Mica, in sheets, 4 in. by 2 in. . . o 3 I 0 2 6 — — — Per i-oz. bottle, 2/-. Other sizes cut to order. ,, Scales 0 2 2 0 — — — Microcosmic Salt, extra pure 0 2 i 6 i 5 — i 4 Millon's Reagent — — — See Special Reagents, p. 1237. Molybdaenum Sulphide 3 o — — • — Morphia, Pure, crystal 16 6 — • — — • ,, Acetate 13 6 — — — ,, Bimeconate . . 17 o — — — Prices variable. „ Hydrochlorate 13 6 — — — Sulphate, cryst 13 9 • — — — „ Tartrate 16 6 — — — 1 Nahrstoff (Heyden) — — . — • — • Per 4-oz. tin, 3/6. Naphtha, Coal 0 I 0 10 — — —~ Wood, best . . O 2 i 6 — — ,, for Potassium, etc. 0 2 i 9 — — Naphthaline, Crystal, resublimed 0 I o 4 — - o 3 . Naphthol, Alpha, recryst. o 4 4 o — ,, Beta, purified O 2 i 3 zs^S gBsg^ JCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &. TATLOCK (LOM)ON) LTD. Price List of Chemicals and Reagents (continued} . Per Ib. Per Ib. Per Ib. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. s. d. s. d. S. (/. Naphthylamine, Alpha, pure white . . 0 6 6 0 — — • — Beta crude . . 0 3 3 ° — — — ,, ,, Pure 0 8 8 o — — — Narcotine, Alkaloid 2 6 — — — • — Nickel, Coils for the wet assay of tin . . — — — — — Each, 1/4 ; per doz., I5/-. Cubes, 98-99% . . o 3 2 9 — — — ,, Carbonate o 3 2 6 — — — ,, Chloride o 3 2 3 — — — „ ,, pure, cryst. ° 3 3 o — — — ,, Nitrate, pure 0 2 2 0 • — — — Oxalate o 5 5 6 — • — — „ Oxide, black, extra pure i 8 — — — • — „ ,, pure, hydrated o 9 9 o — — — Nickel, Oxide, coml. o 3 2 3 — — ,, Phosphate o 4 4 o — • — • — • ,, Sulphate 0 I 0 IO — — — ,, ,, extra pure o 4 4 *-* — • — — ,, ,, ,, free from cobalt o 9 9 o — — — ,, ,, Ammonia 0 I o 8 — — . o 7 Nicotine, Extra pure 7 6 • — — — ,, Tartrate 9 ° — — — — Nitraniline, Meta, pure i 6 20 0 — — — Nitrobenzole, best (Ess. of Myrbane) 0 I I 0 — 0 II — Nitron (Reagent for Nitric Acid) 8 o — — — — Nitronaphthaline, Alpha, pure 0 2 i 3 — — — Nitroso-beta-naphthol, cryst. 2 O — — — — Nitrotoluol Ortho, liquid <> 3 2 3 • — — — Para ' o 3 •2 6 — — — Nut Galls, ground 0 2 2 0 — — — Nutrose 9 o ~~ ~ Per 4-oz. packet, 2/6 Oil, Carbolic O 2 i 6 ,, of Amber, rectified — 2 6 ,, ,, Bergamot 2 0 — — — ,, ,, Castor, finest Italian — . 0 10 o 9 o 8 o 7 „ Cedarwood o 3 2 6 ., ,, ,, for immersion, ND 1.515 — — — , Per 3o-gramme bottle, i doz., I2/-. „ Cloves, best English refined . . o 8 7 6 — W. Qt., 6/3 per Ib. ,, Eucalyptus o 3 2 6 _ „ Lavender (Spike Oil) o 6 6 o . ,, Lemon I 0 ,, Olive, superfine 0 2 i 6 i 5 1 4 — \V. Ot., 1/3 per Ib, „ Orange I 2 14 o . „ Origanum 0 6 6 6 ,, Peppermint . . 3 ° . . „ Sesame O 2 i 3 „ for lubricating clocks, watches, etc. — Per 7 oz. tin, od. ; per doz (; „ for lubricating fine machinery Orthoform 5 o • — — — — Per J-gallon tin, 3/-. Ortol v/ Oxygen Mixture O I I 0 0 10 o 9 ^^~~ Per i-oz. bottle, 2/-. ,, Cubes, for generating gas 0 2 2 0 7 . „ Compressed gas in cylinders . . ^•^ _ r""*j*BaSgfrT=rf^ r^ensi Pricesjon application (see page 581). /J^S_ Lp 14- • CROSS STREET • HATTCW GAR DEIST, E-C 1222 ^WFBAIRD &TATLOCK (LONDON) LTD.**' IIS Price List of Chemicals and Reagents (i»*&**eS). ; : . Perlb. Perlb. far for far Perot. Pe: 14 Ihs. i& Ibs. s. 4. s. i. r. d. *.*.*.*. Oxylith for generating pure oxygen . . — — — — — P«r Ib. tin Ozokerit, Refined — 10 — — — Palladium Foil — — — — — Per gnunitte. 9/6. Chloride — — — Nitrate — — — 6J6. Oxide _____ Pancreatine, Absolute (Rhenaniai Per 25-grm. bottle, 3/6. Per so-gm. bottle. 6/6. Paraffin. K;r.r.ed white, M.P., i< :•- 0106 — o 5 — no- F. 0 I Q — 06 — 115 F. oio- — 06 — I2CT F. 0 I 0 { — 07 — :.v F. 0109 — 08 — 130' F. 0109 — 08-. t35°F. O I O IO — o 9 — Paraffin. Grubler's, M.P.. 45 C. . . — — — — Per K3o.. 3/. 5jt*C — — — — 54' C. . . — — — — ^ C. .. — — 60° C. . . — 5/9- lal hard, M.P., ;_ O 2 2 O — — — B.P., hquid OIIO _ _ Per gallon. 5/6. Para -amido -phenol Hydrochloride ra pure, cryst. O IO 10 0 — — Paradimethylamidoazobenzol i 9 — — — Paradimethylamidobenzaldehyde *. 7 ° — — — — Par-aldehyde. Extra rmre o 3 a 6 — — — Paraphenylenediamine Hydrochloride i S 24 o — • — - — Parchment Paper — i — — — Pentane. --.indard. for photometric analyses . — . — Per pint, j/- ; per gallon, jj/-- Pepsine Scales, B.P. 10 — Soluble powder. P.B i S — Peptone Powder (Reidel's) „ 0 u I 0 12 6 12 3 12 O II 6 ! Finest quality far bacteriological • Albumen powder (\Vir specially prepared for work. )cial price for large quantities making culture media — 14 6 14 o -„ Petroleum Ether (s« EtJtfr . Phenacetine 4 3 9 Phenacetoline 26 — — Phenol -phthaleine. Pure I 0 12 0 — Phenylenediamine (Meta) Hydro- chloride I q -: — Phenylhydrazine, Pure 0600 — Hvdrochloride , - — — — Phloroglucin, melting point 210° C. free from Di-resorcin 14 o — — — — Phosphorus S::oks ! o 43 o — ain. J in. diam. . . 0550 — — orphous. 0436 — — Chloride, ter. 3 a o — — — .. oxy i o 5 4 o — — — Penta-bromide . . I o 10 So nachloride •UKHHPlHHHHPII J ^CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS/H BAIBD &TATLOCK (LOM)ON) LTD. Price List of Chemicals and Reagents (continued) . 1 Per Ib. Per Ib. Per Ib. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. i. d. 5. d. *. d. s. d. 5. d. Phosphorus Pentasulphide 0 4 3 o — — — See Acid Phosphoric Anhydrous. „ Pentoxide — — — — — Piperazine 9 o — — — — Piperidine, extra pure . . 4 6 — • — — — Platinum, Basins and spatulas — — — • — • — Black — — — — — Cones — — — — — Crucibles, capsules . . — — — — — Foil .001 in — — — — — Gauze — — — — • — Sponge — — — — — Basins and Crucibles, etc. Wire .015 or .02 in. Bi-chloride, solid . . 87 6 — — — Prices according to market, on appli- cation. Unsettled. ,. in 15 grain tubes each 3/9, doz. 445. See General List, pp. 453-460 (1914 Edition) (or sizes and capacities. ,, solution i% i 6 — — • — — „ 5% •• 5 6 — — — — »» ti " 30 grs. Pt. in. i oz. 16 o — — — — Platinised Silver plates, 5| by 2\ in., each 33. • — • • — — — — ,, Asbestos 12 6 — • — — — Plumbago (graphite) Powder 0 I 0 10 — — — Potassium, in pellets 2 6 35 o — • — - — Acetate, extra pure o 3 2 3 • — • — — ,, pure, fused o 4 3 6 — — — ,, coml. 0 2 i 4 — — — Aluminate o 3 3 o - — • — • — Antimonate, bin o 3 3 o — • — — Arsenate, pure, cryst. O 2 2 0 — — — Arsenite, pure . . . . ] o 2 2 0 — — — Benzoate o 7 7 o - — • — — Biborate o 3 2 9 — — — Bicarbonate, extra pure, cryst. o i O IO — o 9 o 8 „ powd. o i O IO — - o 9 o 8 ,, coml. powd. o 6 — o 5 0 4 Per cwt., W-. Bichromate, extra pure . . ' o 2 i 3 I 2 i i ,, coml., cryst. 0 I o 6 — 0 5i o 5 powder 0 I o 8 — • o 7 0 64 pure, fused . . O 2 2 0 — — Binoxalate, pure, cryst. . . O 2 i 6 — — — Biphosphate, Di-hydrogen potass, phosphate (KHj PO4), pure cryst. o 3 2 6 — • • — „ Bisulphate, extra pure, cryst. O I I 0 — — — • ., ,, pure, fused . . O 2 1 4 — • — • — „ Bisulphite, meta, recryst. 0 I I O — — — Bitartrate, pure, cryst. . . 0 2 2 0 — — ,, ,, coml. cream of tartar 0 2 1 3 I 2 — I I ,, Borate 0 3 2 3 __ - Bromate, pure, 100 % . . -si£& o 7 ^SfSA:*-? 7 o •.aaA^e i^ft^it — —^ec?. i /f^N>_ tO 14 -CROSS STREET • HATTON GARDETsT, E-C 1224 BAIRD ScTATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued). Per Ib. PCI Ib. PCI Ib. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. i d. s. d. o. d. Potassium, Bromide, cryst. 0 2 2 0 — I 10 i 9 ,, Carbonate, extra pure 0 2 I 4 i 3 I 2 ,, ,, coml. (pearlashes) 0 I 0 6 o 5 o 4 — ,, Chlorate, extra pure, cryst. 0 2 i 3 — — — ,, ,, pure, powder . . O 2 I 3 — — — coml., cryst. o 6 — o 5t o 5 powd. .. O I o 7 — o 6\ o 6 Chloride, extra pure 0 I o 9 o 8J o 8 — coml. .. — o 4 o 3 — Per cwt., 2O/-. Chloroplatinite, per 15 gr. tube, 3/6 — — — — — Variable'; prices on application. ,, Chloroplatinate — • — • — • — — 1 ,, Chromate, extra pure 0 2 i 8 i 7 i 6 i 4 „ coml. . . O 2 i 3 — 0 II 0 IO ,, Citrate, extra pure o 4 3 9 — — — ,, Cobaltocyanide I 10 — — — „ Cupric chloride o 3 2 6 — — — Cyanate, pure i 4 — — — — ,, Cyanide, fused stick, 40 % 0 2 i 4 i 3 I 2 ,, Cyanide, fused lump, 98 % t to 100 % (double salt), white 0 2 i 3 I 2 I I „ Cyanide, 98 % to 100 % (double salt) powdered o 3 2 4 2 3 — Special prices in I cwrt. zinc-lined cases for export and for larger Cyanide, single salt, fused quantities on application. lump, free from sodium, white, about 95 % 0 2 i 9 I 8 — i 7 grey o 3 2 0 — I 10 i 9 ,, ,, ,, ,, powdered o 4 3 o — — — ,, Cyanide, extra pure 0 10 9 6 — — — ,, Ferricyanide, red, pure, cryst. o 3 2 4 2 3 2 2 — „ coml. .. 0 2 i 6 i 5 — 1 4 ,, Ferrocyanide, yellow, pure 0 2 i 8 i 7 i 6 ,, „ coml. — 0 IO — o 9 o 8 Fluoride, extra pure o 4 4 o — • — — ,, ,, Bi, pure, cryst. o 3 3 o — — — ,, Formate 0550 — — — „ Hippurate . . 2 6 - — — — „ Hypophosphite 0330 — — — ,, Hyposulphate i 3 15 o — — — • ,, Hyposulphite 03(26 — — — lodate i 3 12 o — — — Iodide (P.B.) cryst. I 0 12 O ii 9 ii 6 — • „ Malate 3 o — • — — — ,, Molybdate . . i i 13 o — — — • ,, Nitrate, extra pure — o 9 o 8 o 7 — „ coml — o 6 o 5i o 5 — Nitrite, pure sticks, 90 % 03128 27 — — „ cryst. o 4 4 o — — — „ Oxalate, neutral, coml. . . O I o 8 — — — pure .. _xi£3s O 2 i 8 ~rtt*X^£ i 7 ii» 11 i 6 - — J GARDEN, E'C- |Tj 1226 BAIRD &TATLOCK. (LOM)ON) LTD. Price List of Chemicals and Reagents (continued} . IVr 11.. IVr 11,. |v, II,. lor lor lor Per oz . Per Ib. 7 n.s. 14 Ibs. J.S 11, s. s. d. s. :/. s. ,/. s. d. t. d. Raffinose 6 'Q — — — — Resin — o 5 ° 4i o 4 o 3* ., Pale — o 8 o 7! o 7 o 6] „ Cerate 0 2 2 O — — — Resorcin, extra pure, recryst., white . . o 5 4 6 — — — Resorcinol 2 6 — — — — Rhamnose (iso dulcite) 12 O — — — — Rochelle Salts, cryst. and powder (see Potass and Sodium Tartrate). Rodinol — — — — — Per 3-oz. bottle, 1/4. Rouge, Jewellers', finest quality o 4 3 6 '• — • — ~~~* Saccharine (550) 2 3 30 o ,, Soluble 2 3 — — — — Saccharose, Pure O 2 2 O — — — (cane sugar) •O I o 6 — — — Salicine (P.B.) . . i 6 — • — — — .Tubes of 0.15 0.3 0.45 0.6 0.75 gr. Salvarsan Neo . . — — — 1/6 3/- 4/6 6/- 7/6 ca. (other sizes to order) //• f \ (Tubes of .6 .5 .4 .3 .2 .1 gr. (600) 1) ywv j Sand, Fine . — . o 3 0 2 O li — Cwt., 9/-. „ Specially sifted for cement testing, passes through a 20- mesh, but is retained by a 30- mesh sieve — o 3 — — . — Cwt., 10/6. Santonine, Cryst. B.P. 8 6 — • — — Price variable Saponine, Extra pure white i 6 24 o — • — — Schlippe's Salt O 2 2 0 — — — Selenium, Sticks 2 9 — — — — Silica, Pure precip. O 2 2 0 — — • — Silicium, Metal, cryst 8 6 — — — — Per gramme, 91!. ,, ,, coml. i 6 18 o — . — • — Silver Capsules, etc. 8 o — — — — „ Foil, pure, for assaying . . 10 6 — — — — ,, ,, fine . . 5 6 — — — — • „ Granulated 4 o • — • — — • — „ Leaf books, i/- each. ,, Precip. 6 o — — — ,, Strip, pure, for assaying ro o — — — — „ Wire 5 6 — — — — ,, ,, pure, for assaying . . ,, Acetate 10 0 4 o — i-lb. quantities at cheaper rates. Prices on application. ,, Benzoate . . 3 6 — — - — — ,, Bromide . . 3 6 — — — — ,, Carbonate 4 3 — — — — ,, Chloride . . 3 ° — — — — ,, Cyanide . . 4 6 — — — — ,, Iodide 3 6 — — — — „ Lactate 5 ^ — — — — „ Nitrate, recryst. 2 O — — • — — 14 8 16 oz. u/ii i/io 1/9 per oz. triple cryst. 2 6 — — — ' — ,4 8 16 oz. "' 2/5 2/4 2/3 per oz. 'CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &. TATLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued') . Per Ib. Per Ib. Per Ib. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. 5. d. s. d. s. d. s. d. s. d. Silver, Nitrate, fused stick 2 0 • — — — — ) solution, I % Nitrite O 2 4 6 2. 0 ' . — . (^l-lb. quantities at cheaper rates. Prices on application. Oxide 4 o — • — — Sulphate, cryst. 3 6 — — — • — Tartrate 4 o — . — — — Soap Test, Clark's or Wankyn's — — — • — — Per litre, 5/-. See also page 1236. , White curd O I I 0 — — — , Castille 0 I o 8 — — — Soda Lime (coarse, medium, fine or powder) Sodium, Metallic in Naphtha . . O I o 6 O IO 4 o — o 9 — In i-lb. tins, each 2/9 (without Naphtha). ,, Acetate, pure, fused white . . O I I 0 — — — extra pure, cryst. . . 0 I o 8 o 7 — o 6 coml. — o 5 — — - Aluminate, pure o 8 8 o — — — • coml O I I 0 0 II 0 10 — ,, Aluminium chloride . . o 6 6 o — — — ,, Amalgam o 7 6 o — — — ,, Antimonate, meta 0 10 IO 0 — — — Arsenate, pure, cryst. O 2 i 6 — — — ,, Arsenite, pure 0 2 I 10 — — — • ,, Asparaginate (aspartate) 6 0 • — — — — Benzoate (P.B.) o 3 2. 6 — — — - ,, Biborate (see Borax). ,, Bicarbonate, extra pure, powd. 0 I o 6 — o 5 — ,, „ puriss., free from NH, 0 2 i 3 — — — ,, ,, extra pure, cryst. 0 I 0 IO — — • — ,, „ powder . . — . 0 2. — — 0 ij Cwt., io/-. ,, Bichromate, coml. 0 I o 6 — o 5 — ,, Biphosphate, pure (NaH2PO4 + H20 o 3 2 3 — . — — Bismuthate (for Manganese estimation) I 3 19 o — — — Bisulphate, pure, cryst. 0 I o 9 o 8 o 7 — „ fused 0 I I O — O II O IO In i-lb. bottles (extra). „ Bisulphite, extra pure — i 4 i 3 — — ,, ,, coml. 0 I o 8 — . — meta I O O II O 10 In i-lb. bottles. ,, Bitartrate, cryst. o 3 2, 6 — — . — . ,, Borate, neutral, powder o 5 5 ° — — — ,, Bromate I O 13 6 — — — Bromide, dry . . 0 2 2. O — — ,, Carbolate, dry ,, Carbonate, pure, anhydrous 0 2 0 2 2, O i 3 I 2 — I I „ „ ,, crystals 0 I o 6 o 5 o 4^ o 4 soda O I (58 % alkali) powd. . — . o 3 . — 0 2\ 0 2 ,, Carminate 7 o — ,, Chlorate, cryst. 0 I I O — extra pure, cryst. . . 0 2 2, O — „ Chloride — o 4 — — — 1228 BAIRD &.TATLOCKL (LONDON) LTD. Price List of Chemicals and Reagents (continued) . p. , 11, . JVrlb. l'<:rll>. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. s. d. s. d. s. d. Sodium, Rock Salt — 0 2 — — — „ extra pure, cryst. . . 0 I 0 8 o 7 o 6 o 5 » ,, ,, fused . . 0 2 I 9 i 8 — „ „ white, in square cakes O 2 2 0 — — — ,, Chromate, neutral O 2 i 3 — — — ,, Citrate, neutral o 3 2 6 — — — ,, Cyanide pure . . I 3 12 0 — — — ,, Ferrocyanide pure . . o 3 2 6 — — — ,, Fluoride, pure O 2 i 8 — — — bi 0 2 i 6 i 5 — • — ,, Formate, pure dry o 3 2 0 — — — ,, Glycocholate . . 4 6 — — — ,, Hippurate 2 6 — — — — Hydrate, extra pure, from sodium o 5 5 o 4 10 4 8 — 2 s „ „ pure sticks, about ) 93-95 % NaHO ) 0 2 1 7 i 6 i 5 i 4 In i-lb. bottles. Bottles 3d. each extra."] en „ ,, sticks, about ) H 93-95 % NaHO I 0 I 0 IO — o 9 o 8 E ,, ,, coml. lumps — o 6 o 5i o 5 o 4 14-lb. drums free. w ,, „ ground, about ) 98% NaHO) _ _ i Ib. 14 Ib. tins. ] Tins 5d. 4/3. 1 and I J i cwt. drums [drums ,, ,, pure by alcohol, 7/6 13/6 25/- each. I free. cakes 0 2 i 6 i 5 1 4 — „ Hypochlorite, solution O I o 4 — — — „ Hypophosphite o 4 3 6 — — — „ Hyposulphate, pure cryst. . . o 7 7 o — — — ,, Hyposulphite, coml. pea cryst. — 0 2 — o ij — Cwt., to/-. pure, dry O I o 7 — — — pure, cryst. . . O I o 4 — o 3i o 3 „ lodate . . i 4 16 o — — — ,, Iodide . . I 0 13 o — — — „ Manganate, coml. ,, Metabisulphite 0 I o 6 I 0 0 II O IO — In i -Ib. bottles. „ Metaphosphate o 4 4 o — — — ,, Molybdate, pure I 2 14 o — — • — Nitrate, extra pure, cryst. . . 0 I o 9 o 8 o 7 — coml. 0 I o 4 o 3^ o 3 0 2J Cwt., i8/-. Nitrite, extra pure, sticks (P.B.) o 3 2 6 2 5 2 4 • — • ,, ,, pure, cryst. . . o 4 4 o 3 6 — — ,, Nitroprusside, pure, cryst. . . i 6 20 0 — — — „ Oleate, extra pure, powder . . o 5 4 6 — — — ordinary o 3 2 6 — — — ,, Oxalate, extra pure O 2 i 6 — — — Perborate, medicinal o 4 4 o — — • — ,, Perchlorate o 5 5 ° — — — „ Permanganate, pure . . „ Peroxide, coml. „ Persulphate . . I O o 3 12 0 — — — | J 1 i Ib. tins | Tins Jod- i/3 z/- ^cMfree (8/6 I4/- 23/-perdoz.) ,, Phosphate, extra pure, cryst. (Na,HPO4 + I2H.O) . . 0 I o 8 o 7 o 6 — Phosphite 0770 ^— 1229 BAIRD &raTLOCK (LONDON) LTD. Price List of Chemicals and Reagents (continued] . Per Ib. Per Ib. Per Ib. • for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. i. d. s. d. s. d. Sodium, Phosphomolybdate . . I 0 12 0 — — — ,, Phosphotungstate I 4 14 o — — — • Pyrophosphate, pure, dry . . 0 2 i 9 — — • • — Salicylate, cryst 0 2 2 0 I II — — • „ powder 0 2 I 10 i 9 — - — physiologically pure o 4 3 6 — — — • „ Silicate, pure, cryst. . . O 2 2 0 — — — „ ,, solution cone. — - o 6 o 5 o 4 o 3 „ Silicofluoride, pure . . O 2 i 6 — — • — Stannate 0 2 i 9 — — — ,, Succinate, pure, cryst. I I 13 0 — — — Sulphate, extra pure, dry . . 0 I o 9 o 8 o 7 o 6 ,, ,. .. cryst. . . 0 I o 5 o 4 ° 3i o 3 „ coml., cryst. (Glauber's salts) — o 3 0 2 o li — „ coml., dry — o 4 o 3 — — Sulphide, cryst., free sulphite 0 2 I 2 — • — — • ,, Sulphide, pure, fused 0 2 2 0 — — — Sulphite, recryst 0 I o 6 o 5 o 4! o 4 ,, ,, coml. 0 I o 4 — - o 3 0 2i ,, ,, pure, anhydrous . . o 3 2 6 2 4 2 3 — • ,, Sulphocyanide, pure, cryst. . . o 3 2 9 — — — Tannate powder . . o 4 4 o — — — ,, Tartrate, extra pure, cryst. . . ! o 3 2 6 — — — ,, Taurocholate, pure O II II 0 — — — Thiosulphate (see Hypo- sulphite). „ Tungstate, crude o 3 2 3 2 2 — — pure o 4 3 9 — — • — Urate 1 9 — — — Sorbite — — — — Spermaceti, True o 4 3 6 — — . — Spirit, Methylated, free from gum o 6 — — Starch — o 4 . — — . — ,, Potato, pure, dry — o 6 — o 5 — „ ,, soluble, specially pre- pared for brewers' chemists 0 5 4 6 — — — Starch Paper, per book, 2d. ,, and Potassium Iodide Paper, per book, 3d. ; per doz. books, 25. 6d. ,, Iodide o 6 5 o Starches, Typical samples, tested microscopically— Arrowroot o 6 3 o . Barley o 6 o . Buckwheat o 6 Q Maize o 6 3 o Oats o 6 3 o Pea o 6 3 o Potato o 6 3 o , Rice o 6 3 o . Rye o 6 3 o — — — . Per Cwt., 8/-. (Very scarce, price unsettled.) i i i oz. 34/- 67/6 I34/- Per gallon, 3/6. 1230 BAIRD &TATLOCK: (LONDON) LTD. Price List of Chemicals and Reagents (>i»itinnca). IVr Hi. IVr Hi. IVl III for for for Per oz. Per Ib. 7lbs. 14 Ibs. 28 Ibs. • s. d. s. d. s. d. s. d. s. d. Starches, etc. (continued'). Sago o 6 3 o — — — Tapioca o 6 3 o — — — Wheat o 6 3 o — — — Stearine, Best . . O I 0 10 — o 9 o 8 (Acid Stcaric.) Steel Filings 0 I O IO — — — Stourbridge Clay — O 2 — — — Strontium Metal, ex amalgam, per gramme, IDS. 6d. „ Acetate o 4 3 9 — — — ,, Bromide, dry o 4 4 o — — — Carbonate, pure, white . . O 2 i 4 — — — „ ,, puriss., precip. by ammonia o 3 3 o — — "— Chlorate, pure o 5 5 o — — — „ Chloride, pure cryst. O I 0 IO o 9 — — „ dry O 2 i 6 — — — ,, Chromate . . o 5 4 6 — — — ,, Nitrate, coml., powder . . O I o 6 — — — ,, pure exsicc. 0 2 i 6 — — — dry 0 I o 8 o 7 — — Oxalate 0 2 2 0 — — — ,, Oxide, anhydrous, pure . . o 5 5 o — — — „ caustic, pure cryst. O 2 i 6 — • — — „ Phosphate . . o 3 2 6 — — — „ Sulphate, precip. 0 I I O — — — free — — — from Sodium o 6 6 o — — — Strychnine, Cryst., pure 2 9 — — — — ,, Sulphate 2 6 — — — — Sugar, cane . . , 0 I o 6 — — — Sulphonal (Mercaptol), oxy I O — • — — • — Sulphopyrogallol — — — — — Per 10-02. bottle, 2/-. Sulphuretted Hydrogen, Cubes for generating 0 2 2 0 — — — Sulphur, Cryst., pure . . O 2 i 6 — — — ,, Flowers — o 3 — 0 2 0 li Per cwt., 12/6. Precip. 0 I o 6 — — — 45/-- Roll — o 3 — 0 2 0 1} "/-• Chloride o 6 3 6 — • — — Tannin, Pure, light o 4 3 o — . — — | (Acid Tannic.) ,, Coml. O 2 2 O — — • i Terpin Hydrate, cryst. O 2 2 O — • — - — Thallium, Metal, pure . . 4 6 — • — — ,, Carbonate, pure II 0 — — — ,, Chloride II 0 — — — Nitrate II 0 — — — „ Sulphate II O — — — — Theobromine (Alkaloid) 2 O — — — ^— Thermit, Iron 0 2 2 0 — — Thionine 6 6 — — — — Thiosinamine i 4 — • — — Thorium Nitrate, dry i 3 18 o — — — Oxide, hydrated 3 6 ~~ ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALb ll BAIRD &. TATLOCK (LOM5ON) LTD. F W>J ll/ ^ f^i Bv Price List of Chemicals and Reagents (continued). Per Ib. for Perlb for Perlb for Per oz Perlb 7 Ibs. 14 bs. 28 Ib. i. d. s. d. s. d. s. d. s. d. Thorium Oxide, anhydrous 5 ° — — . — — „ Sulphate 3 6 — — — — Thymol . . o 8 8 o — — — Tincture, Guaiacum o 6 6 o — — - — Tin, Foil, thick, pure . . o 4 4 o 3 6 3 o — „ „ medium 0 2 2 O — — — „ thin .. 0 2 2 0 — — „ Grain o 4 3 o — — — „ Granulated o 4 3 6 2 10 2 9 2 8 „ Sticks, pure o 4 3 9 — — — „ Turnings . . o 4 4 o — — . — „ Ammonia chloride 0 2 _ 0 — — „ Bichloride, cryst., white . . O 2 2 0 — — . „ „ fuming (tetra) o 5 5 ° — — . . Binoxide, coml. (putty powder) . . o 3 2 3 — — „ „ pure white o 4 3 6 — — „ Bisulphide (Musive gold) o 8 8 o — — „ Bromide I 0 — — — . „ Chloride, proto, crystals, pure . . o 3 2 6 . ,, ,, (stannous chloride), strong solution 0 2 i 3 . Protoxide . . o 5 4 6 . Titanium 12 O ,, Chloride, extra pure Toluidin, Ortho, coml. o 3 2 6 — — i io-grm. 25-grm. tubes. 2/-. 4/6 each. „ „ extra pure . . o 4 3 o „ Para, pure o 6 6 o Toluol, Purif., boiling pt. 110° C. O 2 1 3 I 2 i i I 0 Coml 0 I o 9 o 8 Triacetin 2 0 24 o Trichlorophenol, Cryst., melt. pt. 6s°C. 0 8 8 o 9 Trimethylamine, Medicinal 10% o 8 7 6 Tripoli Powder 0 2 / Trikresol, Schering's . . See page 1195. Tropajolin, oo . . o 6 6 o Tungsten, Extra pure . . 7 6 „ Metal, coml. o 8 8 o Turmeric Powder 0 I I 0 O IO „ Books . Sea page 1246. Turpentine, Coml OTfi Oxx Gallon, 6/6. Purif O I JLV If\ 9 W. Qt., i id. per Ib. „ Venice 0 2 \J 2 0 — — — Ultramarine O 2 I 4 Uranium, Metallic "T Per gramme, 2/-. „ Acetate, extra pure, cryst. 2 0 „ Chloride 2 O ,, Nitrate, extra pure, cryst. I 6 18 o Oxide, black, pure 2 3 „ pure red 2 9 — (Acid Uranic.) yellow i 6 „ Phosphate 2 3 Sulphate 2 O Uranine 0 10 o o Urea, Extra pure, cryst. o 7 7 o — ?^te^=s 1232 Price List of Chemicals and Reagents (continued). Per Ib. Per Ib. Per Ib. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. s. d. s. d. $ d s d r li Urea, Nitrate 0 8 7 6 Oxalate o 7 / 7 ° „ Sulphate I Q Urethane o Io" 9 6 Urotropine (Schering's) . . . . 7 — — See page 1194. Vanadium, Chloride 4 o Vanallin i 6 2O 0 Varnishes — Asphaltum o 3 Black japan 0 3 Damar o 3 3 o Gold size 0 2 +f 2 O Hollis' glue, per hot., 6d. ^ Bates' black, „ 6d. and is. Vaseline — I 3 I 2 I I I 0 i-lb. tins. free. White . . i-lb. tin, a/-. Veratrine, Extra pure, P.B 6 6 — — — — Water, Distilled, per gallon, 6d. ; per carboy, 33. 6d. Wax, Bees', white, cake o 4 3 6 — — — Carboys, s/- each extra. „ yellow o 3 2 6 ,, Special red, soft, for physical ex- periments, etc. Westron ) Non-inflammable o 5 5 o — — In i-oz. sticks. Westrosol / solvents . . i 6 1 4 I 3 — Special price for quantities. Xylidine .. o 3 3 o • Xylol, Pure O 2 +J i 6 — — — W. Qt.. 1/4 per Ib. „ Coml. O I o 8 — — — .. 7d. ,. Zaffre o 5 5 o Zinc, Filings O I I O ,, Foil, thin o 4 4 o ~ „ Granulated, free As. O 2 2 0 I IO 1 9 i 8 „ chem. pure . . o 4 4 o .• „ coml. . . 0 I o 6 o 5 ,, Powder, coml. O I o 8 0/7 o 6 ,, Shavings I O 7 0 IO o 9 \J \J o 8 Cwt., 707- „ Sticks, free As 0 ^ 2 6 j 3 „ Sticks, ordinary . . . . . . o i i 3 „ Acetate, pure 0 2 i 3 . „ Bromide o 4 4 o , . „ Carbonate O 2 i 3 — — — pure PR O 2 2 O _ — „ Chloride, pure, fused, stick, white O 2 i 4 i 3 — — .. ,, corn!., white cake O I o 8 — „ Chromate . . O 2 2 O „ Cyanide o 4 3 6 „ Ferrocyanide 0 S 4 6 . „ Iodide . . . . . . ..1x6 18 o . „ Lactate, pure cryst. . . . . 03 3 o — — — „ Nitrate, pure . . . . . . o j i 6 — — „ Oxalate .. .. .. ..0330 ._. X'*'^Ci^\ JL" *»"A _jr-_— »-«r^"-^^^ | ^CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 1233 Price List of Chemicals and Reagents (continued). Per Ib. ivi n> . Per Ib. for for for Per oz. Per Ib. 7 Ibs. 14 Ibs. 28 Ibs. 5. d. s. d. s. d. 5. d. s. d. Zinc, Oxide, extra pure, precip. <> _' 2 0 — — — ,, coml. — 0 8 — — — Phosphate 0 2 2 0 — — — Sulphate, extra pure, cryst. coml 0 I o 8 o 4 o 7 o 3i o 6 o 3 o 5 O 2A Cvrt., 20/-. pure, free from Nitrogen o 3 2 6 — • — Sulphide, pure o 3 3 6 — — Tartrate o 6 5 6 — — Zirconium, Metal, cryst. — — — — Per gramme, 3/3. Nitrate 2 3 — — — „ Oxide anhydrous .. 3 o — — • — • — List of Specially Selected Chemicals for use as Fertilisers and Weed Killers. Ammonium, Muriate „ Phosphate Sulphate Apatite, artificial Basic Slag Bone Ash Bone Meal Calcium, Phosphate mono di Copper, Sulphate Iron, Sulphate Price per cwt. . . 40 O . . 40 O 19 o •• 35 O ••49 . . 14 6 ..86 . . 40 o • • 25 6 •• 32 o 8 o Kainit Chloride of Lime Super Phosphate of Lime Mercuric Chloride Potassium, Chloride . . ,, Nitrate . . ,, Phosphate ,, Sulphate 90% coml. Sodium, Sulphate acid ,, Chloride Nitrate Price per cwl 6 . . 10 6 I . .33. od. per Ib. 15 ' 30 < •• 35 ' .. 18 i .. 8 i .. 4 i 18 < Quotation for other Chemicals and Quantities Given on Application. Pure Standard Solutions. Prepared by a competent Chemist in our own Laboratory. Each solution is checked against a standard, and the accuracy can be thoroughly relied upon, strength of each solution is noted on the label of the bottle. Acid, Acetic, normal „ decinormal Arsenous, decinormal (N/io sodium arsenite) . . standard, for Cl, i c.c.=i c.c. of dry gas Citric, normal ,, decinormal Hydrochloric, normal ,, decinormal 7-5% for soluble starch „ standard, i c.c. = o.oi grm. NH2 in gas liquor, etc. Nitric, normal ,, decinormal Oxalic, normal decinormal . carefully tested anc The exact working Per litre for Per litre quantities quantiti less than of i liti i litre. and ove (. d. s. d. .. 3 6 3 0 .. 3 6 3 0 ..4 6 4 0 60 mm. and o°C. . . 4 6 4 0 .. 3 6 3 0 .. 3 6 3 0 .. 3 6 3 0 .. 3 6 3 0 .. 3 6 3 o >r, etc. . . . . 3 6 3 0 .. 3 6 3 0 ..3 6 3 o .. 3 6 3 0 .. 3 (Bh 6 i 3 SfcS o A 14 • CROSS STREET • HATTON GARDEN. E- C 1234 BAIRD &TATLOCK (LONDON) LTD. Pure Standard Solutions — continued. Acid, Oxalic, standard, to correspond to standard baryta for CO and CO,, i dlt. = i gas, etc. ,, standard, for CH4, i c.c. = i c.c. dry gas, etc. . . ,, standard for CH4, i c.c. = 0.5 c.c. CO, dry gas, etc. Pyrogallic, alkaline, for absorption of oxygen Sulphuric, normal . . „ decinormal ,, ,, standard, i c.c. = i% NH, using i gram of sample . . „ „ ,, for ammonia, i c.c. = i c.c. dry gas, etc. . . ,, ,, Referee's standard for ammonia in coal gas . . ,, „ standard for water analysis Aluminium Hydrate, pure, suspended in distilled water Ammonia, Solution, normal „ „ decinormal „ „ standard, for acidity in beer, etc. ,, „ Referee's standard . . . . . . ,, standard, i c.c. = o.oi mgm. NH, ,, Magnesium citrate solution (Joulie) Ammonium Citrate, sp. gr. 1.09 „ Molybdate, nitric acid solution of, for PaOs ,, Thiocyanate, decinormal | „ „ standard to equal standard silver nitrate for HC1, i c.c. dry gas, etc. . . ; Barium Chloride, normal „ ,, decinormal „ Nitrate, decinormal Baryta Solution, standard, for CO2, 100 c.c. = 0.15 grain C02 . . ,, ,, „ for CO and CO,, i c.c. = i c.c. dry gas, etc. ,, ,, „ for CH4, i c.c. = i c.c. dry gas, etc. „ ,, for removing P2O6 and S03 Cadmium Chloride solution, for absorption of H,S Calcium Chloride solution, standard, for Clark's soap solution . . „ „ for Wanklyn's soap solution „ Phosphate, standard Copper Solution and alkaline tartrate (for Fehling's solution) in separate bottles ,, Pavy's standard, for colour testing Cuprous Chloride solution, acid, for absorption of CO ,, ,, ,, ammoniacal, for absoption of CO Dextrose Solution, standard Hypobromite Solution, for urea tndigo Carmine, standard Iodine Solution, decinormal standard for Cl, i c.c. = i c.c. dry gas, etc. . . „ for SO2, i c.c. = i c.c. dry gas, etc. Hubl's, for iodine absorption of oils and fats ron Perchloride, solution, i c.c. = o.ooi grm. Fe . . ,ead Acetate, standard for colorimetric estimation of lead ,, ,, for HaS i c.c.=i c.c. dry gas, etc. ,, Subacetate solution, for sugar analysis ifagnesia Mixture, for precipitating P,OS •ler curie Cyanide, standard, Knapp's, for sugar analysis Iodide, standard, Sachsse's, for sugar analysis „ Nitrate, standard for chlorides in urine „ „ standard for urea leta-phenylene-diamine solution, for the estimation of nitrites .Ipha-Naphthylamine solution, for nitrites tessler's Reagent Per litre for quantities less than i litre. c.c. dry s. d. .. 4 6 .. 4 6 .. 4 6 4 6 3 6 .. 3 6 .. 4 6 .. 4 6 .. 3 6 ..26 .. 4 6 .. 3 6 .. 3 6 .. 3 6 3 6 .. 3 6 .. 5 6 .- 5 6 .. 4 6 .. 3 6 = i c.c. 4 6 3 6 3 6 3 6 3 6 4 6 4 6 3 6 5 6 4 6 4 6 3 6 6 6 4 6 3 6 6 6 6 6 4 6 5 6 4 6 4 6 5 6 5 6 15 6 3 6 3 6 4 I 4 6 4 6 7 o 8 6 5 6 5 6 6 6 5 6 10 6 Per litre for quantities of i litre and over. f. d. 4 o 4 " 4 o 4 ° 3 o 3 0 4 o 4 o 3 O 2 O 4 o 3 o 3 o 3 o 3 o 5 o 4 o 3 o 4 o 3 o 3 Q 3 o 4 ^ 4 O 4 o 4 ^ 6 o 4 O 3 o 6 o 6 o 4 O 5 o 4 ^ 4 o 5 ^ 15 o 3 ^ 4 o 4 o 4 o 6 6 8 o 5 o 6 o IO O iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS 1235 BAIRD & IXTLOCK (LONDON) LTD. Standard Solutions — continued. Phenol Disulphonic acid, pure, for estimation of nitrites Potassium Bichromate, decinormal Carbonate, normal decinormal Chromate solution, for the estimation of chlorides, 2 oz. bottles, 6d. . . Cyanide, standard, for mercury or copper Ferrocyanide, standard for zinc Hydrate (caustic potash) normal ,, decinormal .. •• seminormal alcoholic ,, solution for absorption of CO2 for NH,, i c.c. = i c.c. dry gas, etc. . . Iodide, standard, for mercury . . „ solution, for estimation of oxygen absorbed, by Tidy's process, 2 oz. bottles, is. 6d. Nitrate $ to ?£* ,, ,, standard, i part N in 100,000 Nitrite, i c.c. = o.oi mgm. N2OS Permanganate, decinormal standard, for N2O3, i c.c. = I c.c. dry gas, etc. solution, i c.c. = o.i mgm. oxygen „ alkaline, for albuminoid ammonia Sulphide solution Kjeldahl's process „ Thiocyanate, decinormal Silver Nitrate, decinormal ,, ,, standard for HC1, i c.c. = i c.c. dry gas, etc. ,, ,, for chlorides in water Soap Solution, Clark's „ „ Wanklyn's Sodium Acetate, acetic acid solution of, for P200 estimation . . ,, Arsenite, decinormal, for chlorine . . ,, Carbonate, normal „ decinormal standard, i c.c. = 0.25 grain S03 ,, Chloride, decinormal standard, i c.c. = o.ooi gm. Cl . . Hydrate (caustic soda) normal ,, ,, „ decinormal . . ,, ,, standard, for milk analysis, i c.c. = o.oi gm. lactic acid „ i c.c = i% NH3 using i gram of sample ,, ,, 10% free nitrogen -25% 1.500 sp.gr. Nitrite, standard, i c.c. = o.oi mgm. N2O3 Phosphate, standard (or ammonio-sodium phosphate), for P206 in manures, etc. . . „ Phosphate, standard, for bismuth „ Sulphide, 10%, free from iron standard, for copper, zinc, lead, etc. „ Thiosulphate, decinormal . . •. „ standard, for oxygen absorbed Uranium, Acetate, standard, i c.c. = 0.005 gm- V^s » „ i c.c. = i % soluble phosphate using i gram of the sample . Nitrate, standard, i c.c. = 0.005 gm. PjOs Water, Distilled, free from ammonia .. .. free from ammonia and organic matter Zinc Chloride, standard, for standardising ferrocyanide in zinc analysis Per litre for quantities less than i litre. s. d. .10 6 . 3 6 • 3 6 • 3 6 .' 4 6 • 3 6 • 3 6 • 3 6 • 15 6 . 4 6 . 4 6 4 6 3 6 3 6 8 6 3 6 4 6 3 6 6 o 3 o 3 6 5 6 4 6 4 6 5 6 5 6 2 6 4 6 3 6 3 6 4 6 3 6 3 6 3 6 3 6 3 6 4 6 5 6 7 6 6 6 8 6 3 6 3 6 3 6 3 6 3 6 2 6 10 6 10 6 10 6 3 6 3 6 10 o 3 o 3 o 3 o 4 o 3 o 3 o 3 o 15 o 4 o 4 o 4 o 8 o 4 o 5 6 a 6 3 o 4 o 4 o 5 o 2 o 4 o 3 o 3 o 4 ^ 3 o 3 o 3 o 3 ° 3 o 4 o 5 o 7 o 6 o 8 o 3 0 ^ 0 J 3 o 2 0 9 o Q 0 9 o i o j j 1236 ear '11 BAIRD &. TATLOCK (LONDON) LTD. *•> rw. MV "^t^J^x^^ INDICATORS. Bottle of Bottle of 50 C.C. IOO s. d. s. d. arminic acid solution 06 ochineal tincture 08 12 ongo red solution 08 I • Hmethylamidoazobenzene, alcoholic solution [ 0 I M ,osin solution . . 06 jrythrosin (iodeosin) solution >6 46 'erric Indicator, for thiocyanate method 08 I J luorescein 10 I 'I ,itmus solution, ordinary 0 1) I O ,, tincture 10 19 [ethyl orange solution 06 o 10 'henacetolin solution i o 19 'enol phthalein solution . . I O I < i 'otassium chromate solution for chlorine 04 07 losolic acid, or corallin solution 08 12 tannous chloride, alkaline, for estimation of glucose by mercury . . * . . 08 12 tarch, soluble, 2% solution 08 12 „ solution, fresh, ordinary . . 10 ,, concentrated and prepared to keep 08 12 SPECIAL REAGENTS. • Reagents for special work, other than those contained in the following list, can be supplied at u few days' notice. s. d. niline chloride solution i 2 per ioo c.c. arfoed's reagent, for glucose 30 per litre. oas' reagent, for free HC1 26 per ioo c.c. rucine solution for the estimation of nitrites 20 per litre. iphenylamine solution, for nitrites 4»" obbin's reagent, for alkaline hydrate 40,, hrlich's diazo reaction, solution (a) i 6 „ „ „ ,, (b) 06 „ sbach's solution, for Esbach's albumenometer 26,, rohde's reagent for alkaloids 40,, linzburg's reagent (Phloroglucin-Vanilin) for free HC1 in the gastric juice 60 per ioo c.c. .aymen's fluid for hsmacytometer 10,, ieffer's reagent, for free HC1 30 per litre. '. tmus solution, prepared according to Kubel and Tiemann 60,, layer's solution, for alkaloids 40,, lillon's reagent for albumen and phenol 12 0 „ 1 /lander- Almen reagent, for sugar 40,, iiloroglucin solution, for lignin 3 9 per ioo c.c. 1 losphomolybdic acid, 10% for alkaloids 14 o per litre. 1 losphotungstic acid, 10% for alkaloids 5 o Jhweitzer's reagent for cellulose .. 80,, J dio-Cobaltic nitrite solution, for potassium IO 0 Shulz's solution, for cellulose 26 per ioo c.c. (CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 6276-6286 MINERALS IN SETS. Elementary Collections (in Cabinets) arranged to illustrate Dana's Mineralogy. 6276s 50 Specimens, small, but all characteristic, with name and locality 6277s 100 Specimens, small, but aircharacteristic, with name and locality 6278s 200 Specimens, small, but aU'characteristic, with name and locality The same number of larger specimens at proportionate prices. Arranged to illustrate Rutley's Text-book of Mineralogy. 6279s 50 Specimens, in cabinet 6280s 100 Specimens, in cabinet 6281s 200 Specimens, in cabinet 6282s 300 Specimens, in cabinet COLLECTIONS OF METALLIC ORES. 6283s Collection of 100 ores of metals, it by i in. 6284s Collection of 100 ores of metals, 2 by 2 in. 6285s Collection of 200 ores of metals, i^ by i in. 6286s Collection of 200 ores of metals, 2 by 2 in. Larger Collections and larger Specimens to any price. MINERAL CRYSTALS. 6287s 25 Natural crystals of minerals 6288s 50 Natural crystals of minerals 6289s 25 Fragments of minerals for blowpipe experiment 6290s 50 Fragments of minerals for blowpipe experiment 6291s 104 Larger fragments of minerals for blowpipe experiment 6292s |o Larger fragments for use with Ross' " Pyrology " 6293s 80 Larger fragments for use with Ross' " Pyrology " 6294s Moh's scale of mineral hardness 6295s Von Kobell's scale of fusibility of minerals . . £0 10 6 £1 1 0 £220 £0 10 6 1 1 0 £330 £660 £220 £330 £550 £770 £0 £0 £0 £0 £0 0 £0 2 5 18 6 12 5 3 6296 6296s Explorer's Mineral Cabinet of minerals, precious stones, &c. Packed in a small, compact, portable, mahogany, well- made cabinet of 6 drawers, containing examples of 30 varieties of precious stones as found in a native state ; 20 specimens of the typical rocks, such as metals and minerals won I found in or associated with ; and 200 specimens of ores of metals and useful minerals, such as are valuable for com- mercial purposes, all with names and localities. All art numbered corresponding to names on labels, etc., so that no difficulty can arise from confusion. The 200 minerals and ores are intended for comparison with specimens that may be found by travellers. Of some species more than specimen is given, showing different characters, etc. Price £12 12 0 CROSS STREET • HATTON GARDEN, E-C 1238 BAIRD &1ATLOCK: (LONDON) LTD. Minerals in Fragments for Analysis, Alabaster Alumstone (alunite) Ambylgonite Anhydrite Anthracite Antimonite Apatite Aragonite Arsenical pyrites (mispickel) „ cobalt „ iron pyrites Arsenic, native Barytes sulphate ,, carbonate Bauxite Beryl Bismuth glanz . . . . i/- oz. Cadmium blende Calamine Calcspar Celestine (strontium sulphate) Carnellite Cerite Cerussite (lead carbonate) Cinnabar Coal anthracite ,, bitumenous ,, cannel „ brown (lignite) ,, specimens showing fossils each „ peat Cobalt glanz Cobaltite Copper pyrites Coprolite Corundum „ " Emery " . . Cryolite powder Dolomite ,, white Emery Fahlerz Fahlore (tetrahedite) Felspar Fluorspar powder ,, lumps Franklinite Fuller's Earth Gadolonite . . . . . . 1/4 oz. Galena Garnierite Garnet Gold Ore IVr II). s. d. I O I O 4 o I O 0 3 1 o 0 9 1 o 0 9 6 o 1 8 2 O o 4 o 3 0 9 1 8 10 O I O o 6 0 8 1 6 2 6 2 6 6 o o 3 O 2 o 3 0 6 1 O o 4 4 ° 10 o 0 6 1 o 2 O 0 6 1 O o 3 o 6 o 6 2 O 2 O O 6 o 4 0 3 1 6 o 4 o 8 3 6 2 O Graphite Gypsum Hornblende Iceland spar I. (selected specimens from 1/6) II. Ilmenite Iron ore bog . . ,, chrome Iron clay Iron ore black band haematite brown „ - red .. ,, „ bloodstone ,, magnetic ordinary „ „ attractable selected specimens from 2/- each. ,, spathic (carbonate) „ titanic (ilmenite) Iron pyrites Kieserite Kupfernickel Labradorite Lapis lazuli (Chile) Lepidolite Limonite Magnesite Malachite Manganite Manganese Marble, white (selected) Meteorites (chips from 3/- each) 2/6 oz. Mica Mispickel Molybdenite Monazite sand Nickel, arsenical Orpiment Orthite Petalite Pitchblende Pyrolusite Pyromorphite . . Quartz Realgar Per Ib. s. d. i 6 o i 10 4 i o o 0 I I o 3 i 3 o i o 2 5 I 2 0 I o 2 2 O O 3 O 8 4 5 5 7 i 9 o 4 o 0 o /« S5«2 MERCK'S PYROGALLIC ACID Produces the highest density to be desired in a photographic plate. It gives at the same time the finest detail required for the most perfect negative (in high lights as well as in shadows and half-tones). Under ordinary precautions it retains all its superior qualities undiminished for an indefinite length of time. For i lid. PRICES. 8 16 lOd. i Ib. tins, 5/6 each ; i Ib. tins, 10/6 each. Tins Free. 32 I oz. tins per oz. 'YROGALLIC ACID. Concentrated Crystal Form. i Ib. occupying same space as i oz. resublimed. In i 8 16 9d. 8£d. 8d. Bottles Free. 32 i oz. bottles. 7Ad. per oz. CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1245 BAIRD &. TATLOCK (LONDON) LTD. Test Papers. These test papers are in perforated rolls, 5 millimetres broad, and in metal boxes each containing sufficient paper for 100 tests. In addition to being very handy for the pocket, they are more economical in use. BIBULOUS PAPER. Red litmus Blue „ .... Phenolphthalein Duplicate Test, blue and red on one ribbon (see figure above) . . WRITING PAPER, white on one side. Red litmus Blue . . Turmeric TEST PAPERS Brazil wood paper, books Congo red paper, books Red litmus books Blue Neutral „ Red litmus papers Blue „ .... Starch paper, books „ and Potassium Iodide paper, books Turmeric books . Congo red Red or blue papers BOOKS AND SHEETS. . . per book per sheet . . per book per sheet TEST PAPERS, best Quality, extra Sensitive. EACH BOOK IN SEPARATE PAPER. Per doz. s. d. s. d. O 2 I 6 O 2 I 6 O *i I 0 O Ji I 0 0 2 I 6 0 3 2 6 0 3 2 6 0 2 I 6 O 3 2 6 O 2 I 2 O 3 2 6 O 3 2 o Per book.' s. 0 2 Per doz. books. ! s. d. i 6 10 o 10 0 15 0 12 0 Per gross books. s. d. 15 0 CROSS STREET • HATTCTN GARDEN, E-C 1246 BAIRD &raTLOCK (LONDON) LTD. INDEX. No. Abbe Apertometer, Zeiss' .. .. 1122-1123 ,, Drawing Apparatus, Zeiss' .. 1111-1112 kefractometers . . . . . . 4983-4987 „ Stereoscopic Ocular, Zeiss' .. .. 1125 ,, Test Plate, Zeiss' .. .. .. 1124 Abel's Petroleum Test Apparatus . . 4993-5000 Abel-Pensky Petroleum Test Apparatus . . 5001-5003 Abney's Pocket Levels . . . . 6432-6433 Absorbing Vessel, Letts .. ... . . 5081 Absorption Apparatus, De Koninck's . . . . 4690 Bulbs, Hempel's . . . . 4663-4672 Mats . . . . . . . . 4206 Tube, adjustable . . . . ' . . 4366 Tube for carbon dioxide . . . . 4741 ,, Pettenkoffer's . . . . 4680 Tubes, Bunsen's . . . . 3135-3136 Accessories for Dennstedt's Furnaces . . 2829-2865 „ Pyrometers . . 54J9-5453, 5486-5489 Accumulator Hydrometers . . . . 3294-3296 Acecometers . . . . . . . . . . 3292 Acetylene Bunsen Burners .. .. 3518-3519 ,, Gas Generators . . . . 3094-3097 Achromatic Condenser, Zeiss .. .. 1136-1137 ,, Objectives, Reichert's . . . . 1253 ,, ,, Swift's . . . . . . 1400 Leitz's . . . . . . 1064 ., ,, Zeiss' . . . . . . 1108 Acid Dishes, porcelain . . . . 2439, 3053 Funnels, gutta percha . . . . . . 2807 Jugs, gutta percha . . . . . . 2137 ,, stoneware . . . . . . . . 2136 Measure, automatic . . . . 4915-4916 Sulphurous, Liquefied . . . . 3071-3072 Acidimeter, Dairy . . . . . . 4933-4934 Ackermann's Calculating Disc . . . . . . 4991 Adapters, Glass, bent . . . . . . . . 1901 small . . . . . . 1900 straight . . . . . . 1902 Adeney's Apparatus for absorption of oxygen in polluted waters . . 5065 for dissolved gases in water 5087-5089 ,, Gas Analysis Apparatus . . . . 4761 Adhesive Plaster, Mead's . . . . . . 758 Adjustable Support with bell jar . . . . 4513 Adjustment Valves for gas cylinders . . 3081-3082, 3092 Aerobioscope, Sedgwick-Tucker . . . . 525 Aerorthometers . . . . . . . . 4747 Aetna Paraffin Lamps . . . . . . . . 6167 Agar Agar Filter Papers, Chardin's . . 2619-2621 „ Media . . . . . . . . 539-540 „ ,, Tubes . . . . . . . . 540 Agate Mortars and Pestles . . . . . . 3568 Air Baths, Asbestos . . . . . . . . 2544 , ,, Lothar Meyer's .. .. .. 2456 , Pump Plate . . . . . . 37I2-37I3 , Pumps . . . . 3705-3708, 3714-3716 , ,, Compressing (Fleuss) . . . . 3720 . ,, Double Barrel . . . . 3714-3716 Air Pumps, Geryk Special Notes „ ,, Mercury Tate's ,, Tester, Lunge & Zeckendorfs ,, ,, Wolpert's Albumenometers, Esbach's Albuminimeter, Aufrecht's Album Presses Alcoholmeter, Manley's Alcoholometers Aid ridge's Blowpipe Alkalimeters, Chopping's Schuster's Allen's Apparatus ,, & Moore's Apparatus ,, Nitrometer Allihn's Condensers Gas Washing Bottles . . Aluminium Basins Capsules Holder for Platinum Wire Pots Rings Scoops Weights Amalgam Mortar, Buck's ,, Scoops Amber Glass Bottles . . Amboceptor American Pattern Earth Borers Ammeters Ammeter and Voltmeter combined Ammonia Apparatus, George's . . , ,, Hoffmann's „ Cylinder Ammoniameters Ampoules, Vaccine Anaerobic Apparatus, Bulloch's . . Anaerobic Jar, Shattock's Analysers, Bausch & Lomb's Analytical Balances ,, Grinding Mills ,, Weights, etc. Anatomical Models Anatomy, Diagrams of Anderson's Potash Bulbs Anemometers Biram's Fletcher's ,, inclined pattern . . ,, Robinson's Aneroid Barometers Surveying and Mining . . Aniline Dyes Animal Balance Lymph Machine Anode, Platinum Anschiitz's Flasks So. 37'7-37«9. 372'. *7" pa-,'<- 707 3577-3579. 3585-359" 3705-3706 4681 4684 . . 781-782 785 441V 22/57 3287 2016 .. 6ll-6l2, 2107-2108 783 3639 3603 2235 4378 1959 3635 508 4509 .. AMV 3838 1830-. 1866 6297 ''335 2073, 2078, 2112, 2115 411 5731 5351-5356 5380-5381 5937 5909-5917, 5932-5934 4758 3293 2116 601 655 1348-1349 1687, 1690, 1733-1735 3659-3676 1791-1876 6014-6046 5997 3761 1903, 1904, 6050-6055 6052-0053 1003 1904 6054-6055 6079-6090 6434-6436 pages 1189, 1206, 1207 .. 451-452 •• 742-745 5257 2302-2303 'CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 1247 BAIRD &TXTLOCK. (LONDON) LTD. INDEX. No. 2287 4139-4141 5°7 410 3184 2600, 6152-6154 1122-1123 1140 1004-1010 1068 1254 1399 1107 124-128, 130-131 Anschiitz's Manometer „ Thermometers Anthrax Outfits Antigen Antitoxin Pipette, Cobbett's Anvils Apertometer, Abbe, Zeiss' Aplanatic Condenser, Zeiss' Steinheil Triplets, Leitz's Apochromatic Objectives, Leitz's Reichert's Swift's Zeiss' Apparatus Cupboards Apparatus, Acetylene Adeney's, for absorption of oxygen in polluted waters . . . . . . 5°°5 Allen's . . . . 783 Anaerobic, Bulloch's. . 601 Arsenic, various .. .. 1905-1911 Beckman's.. .. .. 2755-2772 Blind spot, Haycraft's . . 875 Blood Gases, Barcroft's . . . . 788-789 Hill's . . . . . . 79° foiling point .. 2771,2781 Bruhl's . . . . . . . . 2298 „ Cement, Faija's . . . . . . 5091 Chlorine, Dittmar's . . . . 4043 Classens . . 2546-2547 ,, Cooling, Dr. Savage's . . . . 658 ,, Counting, Esmarch's . . . . 558 Neisser's .. .. 1011-1012 ,, Wolfhugel's . . 554 Culture, Novy's . . . . . . 544 Detmer Moore's . . . . 4518-4582 Digestion . . . . . . . . 3653 Drawing, Bausch & Lomb's .. 135I-I355 Dunstan & Dymond's . . . . 3814 Dupre's, for constant temperature A3&3 1-63631 Electrolysis . . . . 5939-5942 Elutriating, Schultze's . . . . 5705 Embedding . . . . . . 385-399 Engel's, for blood . . . . . . 858 Entomological . . . . . . 659-674 Filtering, Berkefeld . . . . . . 696-706 Cobbett's . . . . . . 687-688 Doulton's.. .. .. 675-681 Gibson's .. .. 2703-2711 Massen's . . . . . . 686 Novy's . . . . . . 693-694 Witt's . . . . . . 2683 for boring corks . . . . . . 2315 for burning one gas in another 5972-5978 for cane sugar . . . . . . 5907 for determination of carbon . . 4707-4709 ,, of sulphur . . 4694-4698 „ of tar in gases . . 4691 for drying blood films . . . . 450 for drying tanned bark . . . . 5226 for estimating capillary attraction of soils 5707 for experiments on plants . . 4518-4584 for filling lymph tubes . . . . 746 ,, ,, ,, Entrican's . . 747 for heating cultures . . . . . . 453 for making briquettes of cement 5200-5209 for measuring flow of water . . . . 6149 for mixing lymph . . . . . . 742-745 for Nitric Oxide, Senier's . . . . 5962 for Physical experiments (see separate list), for sterilisation of gelatine . . . . 449 for sterilising platinum spoons . . 729 Apparatus (or testing Cement Cordite No. 5090-5225 }626 5683-5685 5064 3615-3623 . . 409-424 3430-3432 4688 4761 4762 47<>o-4770 grams ,, hardness of water . . Nitro-glycerine for Wassermann's Test Freezing, Carre's Gas Absorption, Winkler's „ Analysis, Adeney's Bone's Bone & Wheeler's Dittmar's Elliott's Haldane's Hempel's Macfarlane & Caldwell's Orsat's Orsat-Dennis Orsat-Fischer's . . Orsat-Lunge .. 47'7, ' I7'9 I . Pettersens & Palmquist's 4710. V.|;io Stead's . . 4713-4714 Taplay's . . 4731 5686, 5688, 5692-5700 4724 4732-4738 4697 47". 47" 4715 4721-4722 Germinating Haldane's, for expired air Hall & Russell's (for Cement) . . Harvey's Haycraft's Heinrich's Hesse's Hoffman's Horn's H,S, Babo's Coram's Friswell's Kipps L. de Koninck's Odourless Perkins' Jackson's Kjeldahl's Laker's, Puncturing Lead, for H.F. Leunig's (for paper) Melting Point, Roth's ,, Ubbelohde's . . ,, ,, various Mercury distillation Meyer's Milk, Houston's Nitrogen Nitrogen tetroxide Neosalvarsan Ozone, Brame's Paul's Photo-micrographic, Leitz's . . ,, ,, Zeiss' Physiological (see separate list). Plant Physiology Polarising, Educational set of „ Leitz's Swift's Polenske's Projection, Zeiss' Puncturing, Laker's Registration, Phelp's (for plants) Reichert-Wollny Reiset's Respiration of Plants Rocking, Dr. Bours' Root Pressure 793 5212-5213 5069 875 5706 4683 59°' ' 3604 4045-4046 4048 4047 -l"44 4042 A4O4O 5222-5224 3639-3648 868 1966-1967 5243, .5245 •2/73 2773-2780 3812 4328-4329 4939-A4943 3<> v 4693 487 4317 .. 1071-1075 1142 4518-4584 5908 1046-1047 1408-1411 4937 1156-1157 868 4584 4395 4<>«9 4561-4570 .. 4515. 4544-454* CROSS STREET • HATTCTK GARDEK, E-C 1248 BAIRD &TXTLOCK (LOM)ON) LTD. INDEX. Apparatus, Rose's, Fusel Oil ,, Salvarsan Schoppers (for paper) ,, Schwarz's Seed Testinc, Weinzierl's Shaking ,, for Gerber's Tubes ,, Wagner's Silica, Opaque Fused ,, Transparent . . „ Special Notes "606" Soil Testing ., Washing Soxhlet's for milk analysis . . Soxhlet & Henkel s. . Specific Gravity Stirring Dupre's , . 4009-4010 Witt's Sublimation, Bruhl's Sulphur Temperature of Cement Titrating (Plant Physiology) to prove that only external envelope of v 3017-3019 487 5244 3598 5677 3055-3968 4891 5720-5727 2407-2426 2384^2406 page 461 487 5708-5712 A5705 4909-4913 4906 3865 4008 5292, 5293 3954 3654 4749-4757 4566 flame is hot to show behaviour of gases . . combustion of air . . ,, formation of acetylene manufacture of sulphuric acid ,, principle of Bunsen's burner Transpiration . . . . 4510, Urea, Dupre's . . . . ,, Gerrard's . . . . Vacuum distillation. . .. Vapour Density, Hoffmann's . . ,, , » GuyLussac.. ,, Victor Meyer's . . Viscosity . . . . Waller's . . . . . . . . Woodheads' for sterilising platinum spoons 729 Yeast Testing . . . . 4391-4401 Arc Indicator . . . . . . . . 4575 Archbutt's Vaporimeter . . . . . . 5018 Argand burners . . . . 459, 35T4 Fletcher's 3527-3528 Mastes' . . . . . . 3515 Argentometer . . . . . . 332& Arsenic Apparatus various .. .. 1905-1911 Tubes . . . . . . 1908, 1912, 1914 597°-597i 5965-5966 . 5975 . 5961 . 5963 . 5976 4550-4557 . 767 . 768 2291-2295 4363-4364 . 4365 . 4361 . 4345 792 Arzberger & Zulkowsky's Filter Pump "Asbestos Air Baths Cloth Cord Corks Millboard Paper Tape Aseptic Serum Syringes Ash Trays, Porcelain Aspirator Bottles Aspirators, Copper Fletcher's, collapsing Glass, double Muencke's, double .. Assay Apparatus, Holloway's . . Balances, Becker's „ New form „ Oertling's Flasks Furnaces 3686 2544 3551 3552, 6155 2310 3545-3346 355° 3548-3549 482 3554 2132-2134 3732 3054-3055 3736 3733-3734 6258 1736-1738 1748 1739-1747. I749-I75I 2732-2734 6214-6229 Assay Ton Weights, Becker's . . „ ,. Oertling's . . Weights, Oertling's Atomic Models, Collie's ., Kiloart's Engler's „ ,, Lang's ,, .. Perkiii & Kippmg's Atomisers, Formalin Aufrecht's Albuminimeter Autenrieth & Kcrnigsberger's Autoclaves, Chambcrland's ,, for paper pulp „ Horizontal pattern „ or Steam Digesters ,, Schinrmelbush's „ Soxhlet's Autoclave Washers Automatic Acid Measure ,, Blowpipe, Fletcher's . . ,, Cupel Machines „ (.aslighters Pipettes . . ,, Rotary Microtome ,, Spirit Bunsen Burners „ Water Distillation Apparatus . Auxanometer Auxanometer-Klinostats Auxograph, Demonstration B Babo's Sulphuretted Hydrogen Apparatus Bacilli, Tubercle Bacon Thermometer Bacteriological Case of Pipettes, Klein's . Cultures Kilters Labels „ Book Form Specimens Stains Bags, Gas, Goldbeaters' Skin „ ,. Indiarubber Baird & Tatlock's Blowpipe Set . . ,, „ Centrifuges . . ,, ,, Incubators Balance Cases „ „ Leather, for carrying „ Desiccators . . ,, Riders Balances, Analytical Animal „ Assay, Becker's ,, „ new pattern . . ,. „ Oertling's Becker's Assay „ „ Chemical . . 1669, „ „ Dispensing . . „ Beranger's . . „ Bunge's Candle ,, Chemical Demonstration Diamond Dispensing . . '765, for weighing corn „ samples Gas, Lux's . . Hydrostatic No. .843 1847 1839-1842 3559 3557-355* 3561 3560 3562-3564 740 785 H i mocolnrimi't' 817-827. 5035-5044 •• 325-332 5241, 5242 34' 333-A335 342 5681 327 4915-4916 2019 6203 3555-3556 1644-1649 3453-3456, 3463 2268 4576 4499-4500 4493 4045-4046 . . 320 .. 4189 . . 798 . . A538 . . 675-711 . . 1531 3438, €3438 . . 538 pages 1189-1198 . . '995 . . 3044 . . 6160 . . 876-904 . . 294-301 . . 121 .. 1750 1789-1790 1763, 1868 1679-1751 . . 451-452 1736-1738 .. 1748 i739-'75i 1736,1738 1670, 1691-1696 1765, 1766 1776.4554 1697-1707 .. 4829 1676-1735 1680-1682 .. 1772 1766,1785-1787 5672-5673 .. 1788 . . 4748 . . t(jgi CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LOM)ON) LTD. INDEX. Balances, Kuhlmann's Lecture „ Lever „ Lumsden's . . Magnalium . . New pattern Oertling's, Assay „ >, Bullion „ Oertlin >'s. Chemical „ Paper „ Physical Pocket Ruprecht's . . „ Sartorius' „ Specific Gravity, Becker's „ ,. „ for ores, etc ,, ,, Mohr's „ Sartorius' Westphal's Spring „ Jolly's „ Students Balling's Saccharometers Ball Mills Balloon Filters, porous Balloons, Collodion „ Gold Beater Skin „ Indiarubber Balls, Blowing, Indiarubber „ Iron, for bursting Bandage Sterilisers Barcroft's Blood Gas Apparatus Bardeen's Microtome, Leitz's Bark Mills .. Barkometers Barnard's, Calculating Rule ,, Electric Lamp Barley Germinating Box Barographs Barograph & Thermograph combined Charts Ink Pens Barometer Case Tubes ,. ,, Bunsen's Barometers, Aneroid ,, Bunsen's Syphon . . Collie & Shield's . . ,, Fitzroy's „ Gee's „ Ivory Scale „ Marine ,, Mountain „ New design for Mines ,, Pediment „ Self-recording ,, Standard, Portia's . . „ Students' Barrels, Glass, for hypodermic syringes Barrow, Carboy Bars, Photometer Basin Guards Basins, Aluminium „ Berlin Porcelain, various shapes . . „ Bleeding „ Copper „ Enamelled, cast-iron steel „ Evaporating . . „ German Porcelain, various shapes, No. 1708 1677, 1680 1770-1771 1676 1671-1672, 1688 1662, 1748 1739-1747. I749-I75I 1752-1756 Ai7o8, 61708, 1711-1721 1767 1660-1676 1768-1769 1680-1682 1722-1732 1761 1764 1758 1759-1760 17.:? 1777-1784 1773 1660-1676, 1684-1686 3360 3659-3663 2618 1916 1915 .1917 2039-2040 2144-2145 - • 355-358 . . .788-789 1640 3671 5233-5235 3215 463 5699 61937, Ci937, 6073-6078 Ma 3405 4164 Di937 Di937 . . AI936 6070-6072 1924-1925, 6066-6069 6086-6090 . . 1918, 1919, 1921 1932, 6097 6064-6065 1920, 6058 1922, 6060 1937 1931, 6096 1935-1936 6061-6063 61937, Ci937 1926-1931, 6091-6095 1933-1934, 6098-6099 474 3952 4814-4819 2543 1959 1938-1942 3419-3420 1961 1949 1950 1938-1960 1943-1948 Basins, Glass, for Surgical Instruments .. heavy .... 710 oblong . . (Petri Dishes) . . . . 636-641 various forms . . 631-648, 1952-1957, 1960 Spittoons .. 3412-3413 with covers or lids 631-633, 642-644, 647, 648 Heavy Glass, for specimens . . 3384 Lead . . . . - - 1965 Meissen Porcelain 1946 Nickel . . - - 1958 „ Scheibler's, with counterpoise 1951 Platinum . . 2348, -^2348 Porcelain, for milk analysis . . . . 4907 Silica Silver Tinned ,, iron with lid ground to fit Baskets, for Test Tubes, metal . . „ Iron Wire Test Tube „ Tinned Copper Wire . . Bate's Saccharometers Bath Thermometers Baths, Air, Asbestos . . „ ,, Lothar .Meyer's „ Copper, evaporating ,, ,, for mashing ,, ,, high temperature ,, „ hot air . . „ water Crucible Drying, Victor Meyer's . . for dyeing samples of leather „ Le Chatelier Moulds . . „ sterilising vaccines, &c. paraffin embedding Sand Test Tube Water, cylindrical form . . „ Dr. Houston's pattern Electric „ for fat extraction apparatus „ Nickel . . „ with constant level ,, ,, porcelain cover Batteries, Portable Battersea Cupellation Furnace . . Battery Jars, rectangular Bausch & Lomb Analyzers Dissecting Microscopes . . Drawing Apparatus Eyepieces, Huyghenian . Filar Micrometer Lense-stands Magnifiers Mechanical Stage Microscopes Nosepieces Objectives Polarizers Stage Micrometer 2384, 2412-2415 1964 [963 .. I 33S7 '.''. 4068 439 3343-3344 4190 -544 2456 249(1 2491-2494 2462 2454-2461 2463-2488 2538 524° 5221 . . 400-402 . • 385-399 A2540-2542 2539 2511-2514 402 2523-2525 2559-2575 2535 2515-2522, 2529 -=529 5377 6216-11217 342.v Beads, Glass „ Specific Gravity Beaker Covers, glass . . ,, Flasks ,, Beakers, Bohemian Glass, medium form „ ,, squat form ,, „ tall form ,, ,, wide ,, „ Conical, Phillip's I32I-I337 I35I-I355 '344 1350 1319-1320 1290-1317 1342 1264-1289 I33S-I341 '343 1346-1347 J345 197° 3297-3300, 3860-3864 . . 1 98 1 1974 1972 1978 1979 1982 CROSS STREET • HATTOTST GARDEK, E'C 1250 INDEX. No. Beakers, Copper . . . . 1984-1990 Enamelled Steel . . . . . . 1983 Jena Glass, squat form . . . . 1973 ,, tall form, plain . . . . 1976 „ ,, spout . . . . 1977 Resistance Glass, medium form . . . . 1975 ,, squat form .. .. 1971 Royal Berlin Porcelain . . . . 1980 Silica . . . . . . ' . . 2385 Beard's Pressure Regulator . . . . 3085-3087 Beaume's Hydrometers . . . . 3261-3262 Becker's Balances, Assay .. .. 1736-1738 ,, Chemical 1669, 1670, 1691-1696, 1709-1710 ,, Dispensing Balances .. .. 1765-1766 „ Freezing Microtomes . . . . 1618-1631 „ Specific Gravity Balance . . . . 1761 Weights . . . . 1819-1829, 1843, 1866 Beckman's Boiling-point Apparatus . . 2755-2757, 2771 ,, Freezing-point ,, . . 2758-2769 ,, Thermometers . . . . 4147-4148 Beck-Thorp Spectroscopes . . . . 57°3-57O5 Beech Mallets . . . . . . . . 2598 Beehive Shelves, glass . . . . . . . . 3751 ,. ,, stoneware . . . . . . 375O Beer Flasks . . . . . . . . . . 2265 Bell-jars, brass cap and stopcock . . . . 1998 double, Sach's . . . . . . 1999 fitted with rack . . . . . . 656 glass stopcock . . . . . . 1991 green glass, low . . . . . . 1996 „ tall . . . . . . 1997 knob . . . . . . 1993, 1996, 1997 open-top . . . . . . . . 1994 stoppered . . . . . . . . 1992 tubulure at bottom . . . . . . 2000 illows. Foot . . . . . . 2023-2028 U-shaped Measures .. .. .. 3189,3192 It-driven Blowers . . . . . . . . 2029 inch Fittings . . . . . . . . 270-293 •nches, Glass . . . . . . . . 490-491 Photometer . . . . . . 4806-4813 various .. .. .. .. 100-112 nningsen's Soil Testing Apparatus . . . . 5708 nzine Model, Lang's . . . . . . 3560 nzole Retorts . . . . . . . . 3797 Thermometers .. 4130,4197 enzoline, Bunsen Burner . . . . . . 3463 Furnace . . . . . . . . 2822 Lamp, adjustable burner . . 3466-3469 ,, vertical burner . . 3464-3465 ranger's Balances . . . . . . 1776. 4554 rkefeld Filters and Filtering Apparatus . . 696-706 rlin Porcelain Basins, various shapes . . 1938-1942 ,, Beakers . . . . . . 1980 Crucibles . . . . 2327-2332 rnhard's Drawing-table . . . . . . 1141 erzelius Gas Holders . . . . . . . . 3042 Spirit Lamp . . . . . . . . 3449 -metallic Gas Regulators . . . . 433-434 t-meter CO2 Recorder . . . . . . 4771 inocular-Magnifiers, Zeiss' .. .. 1152-1155,1158 xam's Anemometers . . . . . . 6052-6053 irmingham's Microscope Slides . . . . T43i schof's Water Analysis Apparatus . . 5070-5075 ackboards . . . . . . . . 122-123 ackman & Paine's Recording Transpirometer . . 4516 ack's Blowpipe . . . . . . . . 2001 ack and White Glass Plate . . . . . . 630 „ Tiles . . . . . . . . A630 adder Glass . . . . . . . . 3789 ades. Microtome . . 1565, 1616, 1617, 1632-1639 Bleeding Basins Blind-spot Apparatus, Haycraft's Block for Paraffin Kmbedding . . Blocks, Glass „ Porous ., Sporulating „ Wood, for tubes ,, Wooden, in sets Blood Apparatus, Engel's Coagulation Tubes Film Spreaders Gas Apparatus, Barcroft's „ „ Kronecker's Pfluger's . . „ Pump, Dr. Hill's Serum Tubes Viscometer Blowers, Belt-driven Electric * . . Foot Gold-dust Roots' Blowing Balls, Indiarubber Blowpipe Charcoals, compressed ,, ,, natural Sets ,, Slot for Bunsen burners Table Blowpipes, Automatic, Fletcher's Black's „ Fletcher's . . ,, ,, compound „ ,, oxygen ,, for acetylene gas ,, .. gas and air ,, Gasoline „ Glassblowers' pattern „ Herapath's ,, Laboratory pattern . . ,, Methylated spirit Mouth Blue glass-strips Blyth's Vessel with rod and cap Boards, Draining Setting (entomological) . . Sketching Boats, Combustion, fireclay ,, porcelain Platinum Silica Bohemian Combustion Tubing . . Glass Basins ,, Beakers ,. Flasks ,, Funnels „ Retorts Boiler-tester, Simmance and Abady's Boiling-point Apparatus, Beckman's No. 34 '9-3420 875 4°4 634-635 5696 .. 649-650 2090-2092 3948 858 786 1517-1518 .. 788-789 3582 358l 790 54° .. 871-874 2029 2030 2023-2028 6238 2033-2037 2039-2040 2041-2042 2043 A6i55-6i6o 3481 2038 2019 2001 2017-2020 2017 2018 2OI3 20IO-2OI5 2022 2014 2OO9 2021 2016 2001-2009 3881 5079 129 667 6442-6443 3775 3773 62360-2362 2386,2411 3114-3115 1952-1954, 1956, 1957 1972, 1974, I978. !98'. 1982 1981, 2716, 2726, 2730, 2733, 2737 2783 3791-3793 4725 2755-2757. 2771 WaJcer & Lumsden's . . 2781 Bologna Vials .. .. .. .. 3817 Bolt-head Absorption Tubes . . . . 2731 Bolt-heads . . . . . . . . . . 2729 Bolton & Revis' F.xtraction Apparatus . . . . 2558 Bomb Calorimeter, Mahler's . . . . . . 5645 ,, „ " Sarco " .. .. .. 5646 Bone Spatulas . . 3830 ,, Ash Cupels, Deleuil's . . . . 6195 „ & Wheeler's Gas Analysis Apparatus 4766-4770 Bone's Gas Analysis Apparatus . . . . . . 4762 Books of Labels .. .. 1531. A3436 Laboratory Note 2627-2630, 2635, A2635 iCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK (LONDON) LTD. INDEX. No. pages 1173-1186 2049-2051 2313-2316 Books, Scientific Borers, Charcoal „ Cork Earth, American pattern „ „ Frankels' „ „ Gruner's „ Orth's .. Potato Bossheads Boston's Forceps Botanical Collecting Cases Drying Paper Lantern Slides Models Mounting Paper Press Specimens Trowel Botany Diagrams Bottcher's Microscope Slides Bottle Brushes „ Caps, Indiarubber „ Trays, Stoneware Bottles, Amber Glass . . .. Aspirator „ Canada Balsam „ Cedar Wood Oil Culture, Novy's Roux. . various Drop, Chopping's „ ,. groove in stopper „ .. pipette stopper . . „ „ „ stopper and glass cap „ ,, Schuster's ,, ,, solid rod stopper „ Enamelled Label . . 2066-2068, 2074-2077 English Flint Glass, handmade . . 2054-2055 Moulded . . . . 2056-2058 „ ,, Winchester series . . . . 2060 Ether Extra Wide Mouth „ Flat-stoppered N.M. W.M. . „ for Shaking Apparatus „ for Water Samples Gas . . „ Gas Exploding „ „ Washing . . ,, Glass for Mercury „ Gutta Percha . . ,, Iron, for bursting „ „ (mercury bottles) . . „ Jena Glass „ Morphia Assay, Gardner's Museum .. Oil . . Pressure Reagent ,. Resistance Glass Sample, stoppered Sand Blasted Labels Serum Show ., Soyka's Specific Gravity. Chancel's Drilled Stopper. . for gases ,, solids and liquids „ syrups Regnault's 5728 5729 573° 2219, 3910, 3917. 5290 1503 4415 4420 44°3 4585-4659 4421 4417-4419 4402-4404 4416 4408-4412 '435 4074 501 4277-4279 2073, 2078. 2112, 2115 2132-2134 . . 2094, 2O95, 2098 2093, 2096, 2097 543 545 • • 543-547 613, 2106 2103 2104-2105 2100 . 6ll-6l2 2099 2109 617-619, 2059, 3365 . 2061, 2063, 2065 2059, 2062-2064 5724-5727 5066 3020 4371-4382 2IO2 2150 2146-2147 2139 2069 3205 3366-3368 2084 2140-2143 2054-2077 2070 2085 2071-2072 2H2-2II5 -154-2155 • 724-725 3854 3848 3854 3866 3855 3857 No. 3850 3852 •• 3849 3853. 3856 2151-2152 Bottles, Specific Gravity, Standard „ Wanklyn's „ Warden's ,, with counterpoise „ ,, thermometer Specimen, inverted stoppers „ mushroom shape Spectrum Sputum Stoneware, for Mercury . . „ with stopcock Sugar Sample Tin . . Tube ,, in cases . . ,, stoppered with metal cap Unstoppered, English moulded . . (Kali bottles) N.M. W.M. Vaccine Wide mouth 617-619, 2059, 2062 ,, With metal screw caps . . Weighing, various Woulft's Bourdon Vacuum Gauge Bour's Rocking Apparatus Bousfield's Pyknometers Stills Bowls, Glass, for surgical use Box Photometers, Lummer Brodhun Boxes for carrying samples of water holding glass plates microscope slides sending slides by post sterilising bandages iodoform gauze lymph tubes needles, etc. Petri dishes pipettes ,, Glass, for catgut ,, ,, various shapes „ Iron, for sterilising instruments ,, Killing, Zinc „ Metal, for CO2 . . ,, Resistance ,. Store (entomological) ,, Tin, for samples ,, with glass bottom „ lids „ Wood, Boxwood Rules .. .. .. 3218-3227. ,, Scales, horizontal . . . . 3-r> vertical Top Corks Boys' Calorimeter .. .. .. 5610-5611 „ Geometric Stands . . . . 429 : Brackets, Iron Brain Jars, Glass . . . . . . 3386, 342lS ,, Stoneware Bramah Press Models .. .. .. 3786 Brame's Ozone Apparatus Brass Cased Thermometers . . . . 4100-4107 Brass Filter Pumps . . . . 368' Gratings for Sinks Hinges . . . . . . . . . . -• Hydrometers .. .. .. ^<'> Plugs for Sinks .. .. ... . . 16 Retort Rings -1357 . 521-522 2101 2135 2I1O 21,., 2OS6-2O92 2148 2111,2117 2089 2082-2083 2079 2080 2116 2064, 3365 3426 2118-2124 2127-2131 3701 5-17 5297 5286-5287 3409-3411 4845-4846 • 73i-73<> 44' i 1(11-1484 . . 626-627 • . • 1 14-447 • 44°. 448 3393 621, 624, 2150-2164 • . 3°73 5318-53*5 . . 672-673 CROSS STREET • HATTTST GARDEK E- C BAIRD &TXTLOCK (LONDON) LTD. INDEX. Brass Sheet, perforated Stopcocks Syringes, condensing ,, exhausting ,, exhausting and condensing Tray for Cordite Cutter T. Tubes Y. „ Brau er Grain Tester Bredt's Receivers Brewers' Thermometers Bridge Boxes, Wheatstone „ Glass for Catgut Boxes . . ,, Slide Metre ,, Universal „ Wheel Brine Pipe Thermometers Brinometers, Brass Glass Brix's Saccharometers Broegger-Harada's Soil Testing Apparatus Brown & Duvel's Moisture Tester Brown Glass Jars, Dr. Shattock's Browning's Spectroscopes 5733, 5734, 5738- Bruhl's Apparatus ,, Sublimation Apparatus Brushes, Bottle Burette Camel Hair for burnishing „ cleaning bucking boards ,, ,, mortars . . ,, ,, silver, etc. „ stencils Glass Test Tube Tube Buchner's Funnels Tubes Suck's Amalgam Mortar Suckets, Iron, Enamelled Laboratory Bucking Board Juckmaster & Gardner's Mercury Pump . . Sulbs. Condensation Diffusion Distillation, Gray's Exploding HC1. . . ..... Nitrogen, Fresenius' ,, Volhard's ,, Will & Varrentrap's „ with funnel Potash, Anderson's Delisle's Dittmar's Gomberg's Hill's Liebig's Mohr's New form Ure's Specific Gravity Vaccine Vapour density, Dumas' Bulldog Forceps Bulloch's Anaerobic Apparatus Tubes Bullion Balances, Oertling's Bunge's Balances Weights No. 5719 4036-4040 3710 37°9 37" 3638 4338 4337 5683 2300-2301 4191-4194 5318-5320, 5325 3390 534°-5343 5344-5345 5326-5327 4178 3353 3290-3291 33°i 5710 57°3 655 A5739, 577°-5773 2298 3654 4074 .,075-4076 4078-4080 6162 6163 6164 6165 6365 4°77 4069-4071 4072 2805 • • 528-529 6297 6259 726 6189 • • A3588 2446 3652 3760 3760 3596 3595 3593 3594 3772 3763 3762 3768 37&3-3764 3765, 3766, 3769 3767-3770 377' 3867 2116 4346 1487 601 53° 1752-1756 1697-1707 , Ei8o3 1918, I'll'.. 1924-1925 Bungs Bunsen Burner and Spirit I ..imp combined ,, Burners Acetylene Finckner's fittings Fletcher's for retort stand French pattern Marshall's Meker porcelain small " Sparsam " . . Spirit Teclu pattern with adjustable extensions ., broad flame „ bye pass four tubes rose tops. . stopcock stopcock and jet . . three tulu-^ Bunsen-Kemp Gas Regulator . . Bunsen's Absorption Tubes „ Apparatus for explosive gas . . ,, ,, „ hydrogen „ „ „ water . . ,, Barometers . . ,, Barometer Tubes Clips Eudiometers.. Filter Pump Furnace Gas Holders Ice Calorimeter Bunte's Gas Burettes Burette Brushes „ Caps „ Clamps, jointed ,, Clamps, plain ,, Floats, Erdmann's „ Jets Stands Burettes, Gas, Bunte's ,, ,, Franke's „ „ Hempel's „ ., Measuring, Wills' ,, Mohr's, with enamelled band . ,, ,, ,, jet and pinchcock „ stopcocks ,, second quality „ standard graduated . . ,, Weighing, Ripper's Burgess" Colorimeter Burners, Argand Fletcher's Maste's Bunsen Clay „ Concentric, Fletcher's ,, for Incubators ,, „ soldering bolts ,, ,. thermostats High Power, Fletcher's Incandescent Luminous flame Meker „ Ostwald's Paraffin Oil . . 347°- M7» 3474-35'° 35<>3 3479-3484 3517 3508 3510-3512 3475. 3476 3493-3497 3498-3490 3504-3505 3488 3453-3456, 3463 3500-3501 3487. A34»7 3489-3490 3486 35°7 U74 3485 3502 430 3135-3136 5969 . 5967 '...50-6059 IX If >f 1-6069 2211 3M3 .. 2820 ^028-3029 3429 4742-4744 4075-4076 2221, 3909 J220. 3U'» 3140-314! 3'>3<>-3934 4742-4744 4746 4660-4662. 4745 3624 3*30-3*3' 3'27 3126, 3132. 3133 3122-3125 3134 5086 • • 459. 35 ' 4 3515 3474-35io 2883-2884 3532-3533. 3538 • 455-456 3843 5284 3538 460 3509 3493-3497 3513 3460 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS Sofas 12.53 BAIRD &TXTLOCK (LONDON) LTD. INDEX. Humors, Petroleum . . Radial, Fletcher's . . 35*5 Ring, with bosshead for upright Standard, Fletcher's Star, for spirit burner Tube, Fletcher's Burnishing Brushes Butter Refractnmeter Button Hammers „ Moulds Butts, Brass Cabinets for Microscope Slides . . „ Microscope, Dr. Rees . . „ Tool ,, Urine Testing Cadmium Cells Calcimeter, Clarke's Scheibler's Calcium Chloride Towers „ Tubes, various Calculating Disc, Ackermann's . . Rules, Faber's .. 3208-3211, „ Slide Rule, Barnard's .. Fuller's Calendar's Recording Pyrometers Calor-graphs Calorimeter Jars Calorimeters, Bomb, Mahler's . . ,, " Sarco" Boys' ,, Fischer's „ Hempel's „ Ice, Bunsen's „ Junker's.. ,, Recording, Simmance & Abady's Roland Wild's Rosenhains' ,, Simmance & Abady's „ Thompson's „ Wm. Thomson's Cambridge Microtomes ,, ,, Sliding Camel-hair Brushes Camera Lucida, Swift's Zeiss' Campbell's Prospector's Set Campbell-Stokes' Sunshine Recorder Can for Sterilised Water Canada Balsam Bottles . . . . 2094, Candle Balance Candles, Filter, Berkefeld „ „ Massen's ,, ,, Reichel's ,, Standard Cantilevers, Iron Canulae, various Capillary Attraction of Soils Apparatus . . „ Dynamometer, Haig's Electrometer Tubes . . 5254, 5255 „ Electrometers . . . . 5248 ,, Tubes, with joints Caps, Burette ,, Indiarubbcr Capsule Spoon Capsules, Aluminium . . ,, Copper, for testing malt Glass ,, Meissen Porcelain No. 6166-6170 3529-3531 457-458 3520-3524 3456 3526 6162 4968-4974 6240-6244 6303-6305 . 272-273 1461-1484 657 2594-259.5 . 764-766 5263-5266 5214 5210 2191-2192 2177-2190 4991 3213, 3214 3215 3216-3217 5574-5583 5612-5616 5629, 5632 5645 5646 5610-5611 5630 5658-5661 3429 5644 5612-5616 5617-5627 5637-5643 5607-5609 5631-5636 5628 1568-1596 1577-1585 4078-4080 1405-1407 1175-1181 6159 6117 366 2098 4829 706 689 691 5225 293 . 484-486 57°7 787 5260-5261 5253. 5259 4312. 4313 3M2 . 498-501 3878 3635 2495 646 2325 2095, 4831, Capsules, Nickel, for milk analysis „ Royal Berlin Porcelain „ Silica Carbolimeter, Muter's . . Carbon Dioxide Bi-meter Recorder „ Box . . „ Fine Adjustment Valve . . Gas . . „ Recorders . . . . 4771 Electrodes for Hoffman's Apparatus'] Tubes Carbonic Acid Apparatus, various forms . . „ „ Flasks „ ,, Meter, Wolpert's Carboy Barrow Stand Card Frames or Holders Cardboard Counting Squares ,, Scales, horizontal ,, ,, vertical Cardioid Condenser, Zeiss' Carmody's Clamps Carnegie's Universal Stand Carr's Crucible Furnaces Carre's Freezing Apparatus Cartier Hydrometer, Brass Carrier's Alcoholometers Cartilege Knife Cases, Apparatus Balance Barometer Filter, Japanned Tin for Microscope Slides Paraffin Blocks samples of water ,, „ Army pattern „ „ Dr. Houston's ,, „ Dr. Pake's . . Insect Museum Polariscope Shaking, to hold Gerber's tubes . . Wood Block Cassall's Porcelain Slipper Catgut Boxes, Glass „ Jars, ,, Cathcart's Microtome Catheter Cylinder Jar ,, Troughs, Glass „ Tube Cathetometers, Reading Cathode, Platinum Cavendish Eudiometer Cedarwood Oil Bottles. . Spills Cells, Cadmium Conducting Electrolytic Glass, various shapes Half, with stand and cylinder Kohlrausch's Resistance Stand of five Celluloid Plate for weights Cement Apparatus, Faija's ,, Flasks, Leipper's ,, ,, Stanger & Blount's ,, Gauger, Faija's ,, Hopper ,, „ Testing Apparatus, Mann's No. 2506 2326 2421-2422 3253 477> 3073 3092 3069-3070 4848-4857 5936 3137-3138 2165-2176 4684 3952 3953 . . 281-283 556 3233-3236 3240-3242 "44 2225 3946 2904-2908 3430-3432 3354 3288. 3289 1526 124-128, 130-131 121 2583-2584 1461-1484 1483 • 731-736 732 731 736 674 . . 124-128. 130-131 583° 4895 2090-2092 4917 3388-3390, 3393-3395 3391-3392 1561, 1564 3397-3399 3398 . • 3396, 3401-3404 3397 3056-3066 5258 3M5 2096, 2097 2048 5263-5267 5299 5300-5302 2156-2164 5267-5269 5308. 5309 2093, 5303 53°5, 53°4 5266 1880 5216 5215 5090 5092 5217 CROSS STREET • HATTOW GARDEN, E-C BAIRD &TATLOCK (LONDON) LTD. INDEX. Cement Testing Apparatus, Schumann' „ ,, Machines Centipede Tubes Centrifuge B. & T. Registered Designs Chopping's Electric Hand Martin's, Electric Water Cereals, Collections of . . Chains, Land Chamber, Muscle . . Chamberland's Autoclaves ,, Filter Tubes Chamois Skins Chancel's Specific Gravity Bottle Channel Pipes, Fireclay Charcoal Borers Furnace, Liebig's Pastilles ,, Supports Pencil , Saw Charcoals, Blowpipe, compressed ,. ,, natural Chardin's Filter Paper Charts, Chemical, Low's Clinical ,, of the elements „ for Barograph ,, ,, Sunshine Recorder . . Chemical Balances ,, Becker's ,, Bunge's Labels, book form Lecture Charts, Low's Thermometers ,, Double Scale ,, Long Chemicals . . :mistry, Illustrations of, Johnston's icsts, Ice evalier's Cremometers Chimneys for Bunsen Burners . . ,, Glass .. Mica isels iride of Calcium Towers „ „ Tubes, various lopping's Centrifuge Drop Bottle ,, Shaking Machines -hromometers, Wilson's 2hurn Klutriator, Hilgard's "ider Hydrometer Circular Levels Nitrometer, Brass laisen's Manometer lamps, Adjustable Jaws Burette, jointed „ plain Carmody's Double Jaw for fixing tubing to taps ,, indiarubber tubing . . „ watch glasses Nitrometer, double Right and Left Screw Clark's Arsenic Tubes larke's Calcimeter Classen's Apparatus, electrolytic No. s . . 5218-5219 5095-5209 S3' . . 894-895, 899-904 . . 892-893 . . 880-883, 892-904 . . 876-878 A89I-F89I 879, 884-891 • • A5732 6444-6457 791 •• 325-332 . . 683-684 6171 3854 .. 175-207 2049-2051 2821 2044 2045 2046 2047 2041-2042 2043 2619-2621 5980-5982 4137 - • 5979, 5985-5987 .. DI937 6118 1676-1733 1691-1696 1697-1707 3436-3437 5980-5982 4110, 4114-4125, 4127 4132 4127 .. pages 1187-1246 .. ' 5983 -.383,384 4923-4924 3483-3484 A459 456 2596, 6172 2191-2192 2177-2190 . . 892-893 613, 2106 . . 905-907 5024 57" 3301 • • 495-496 • • A3352 2286 . . 2216, 2218, 3913 2221, 3909 222O, 3908 2225 2217, 3914 245 2207-2211 2212-2213 2222, 3910 2214-2216, 3911-3914 1913 5214 2546-2547 Clay Burners „ Troughs .. „ for blowpipe work Clayton, Beadle & Steven's Extraction Apparatus Cleaners, Test Tube " Climax " Clinical Thermometers Clinical Case, Strong & Seligman's Charts Mercurial Manometers Thermometers ,, " Climax " ,, Veterinary Clinograph Clinometer Compasses No. 2883-2884 2881-2882 20J2 A2557 4°73 •4138 799 4'37 . 815-816 4<33-4'35 4138 4136 644' 6416-6417 Clinometers, Pocket . . . . . . 6423, 6424, 6427 Clinostats . . . . . . . . 4517, 4583 Clips for Burettes . . . . . . 2203-2206- ,, indiarubber tubing . . . . 2207-22TI ,, staining dishes . . . . . . 595-596- ,, watch glasses . . . . 2212-2213 Mohr's . . . . . . . . 2203-2206 Universal . . . . . . . . 4083. Clock Glasses . . . . . . . . . . 4349 Clock, Electric . . . . . . . . 321 Cloez Gas Washing Bottles . . . . . . 4376- Cloth, Asbestos .. .. .. .. 3551 „ Wire .. .. .. .. 6381-6383 Cloths, Selvyt . . . . . . . . 4335 Clover Sampler . . . . . . 5689-5690 ,, Testing Machine . . . . . . 5702 CO2 Recorders, Bi-meter . . . . . . 4771 „ Simmance-Abady's . . 4848-4857 Coal Gas . . . . . . . . . . 3075 Cobbett's Filtering Apparatus . . . . . . 687-688 ,, Pipettes .. .. .. .. 3184 Coddington Lens . . . . . . . . 4428 Coil, Induction . . . . . . . . 5378 „ Resistance . . . . . . . . 5379 Cold Storage Chests . . . . . . . . 383-384 Coleman-Archbutt's Viscometer . . . . 5017 Collapsible Metal Tubes . . . . 754 Collapsing Aspirator, Fletcher's . . 3°54-3°55 Collecting Cases, Botanical .. .. .. 441 5 Collection of Cereals . . . . . . . . A5732 ,, ,, Weed Seeds . . . . . . 5732 Collie & Shield's Barometer . . . . 1932, 6097 Collie's Atomic Models . . . . . . 3559 Collodion Balloons . . . . . . . . 1916 Colorimeter, Autenrieth & Koenigsberger's 5°35-5°44 Burgess' . . . . . . . . 5086 Dubosq' . . . . 5032-5033 Stammer's . . . . 5028-5030 Stokes' . . . . . . . . 3202 Walpole's . . . . 5025-5027 Combination Lens, Leitz's . . . . . . 1065 Combustion Boats, Fireclay . . . . . . 3775 „ Porcelain . . . . . . 3775 Silica . . . . 2386, 2411 Furnaces . . . . . . 2815-2872 Dennstedt's . . 2824-2835 Gas Analyser, Taplay's . . . . 4731 Recorders, Simmance-Abady's . . 4847 Tubes, Glass . . . . . . 4309 ,, Iron . . . . 4308, A4308 „ Porcelain . . . . 4306-4307 „ Quartz (Silica) . . 3101-3103 Tubing, Bohemian . . . . 3114-3115 „ Jena '. . .. .. 3116 Compasses, Clinometer . . . . 6416-6417 „ Hedley's Dial . . . . 6420-6421 Lean's ,, .. .. 6418-6410, ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD ckTATLOCK (LONDON) LTD. INDEX. Compasses, Pocket „ Prismatic Compensating Eyepieces, Leitz's „ „ Swift's „ „ Zeiss' . . Compound Blowpipe, Fletcher's Compressed Air Burners, Meker „ ,, Manometer Cork Sheets Compressing Pump, Hand Compressors for Meat Research Computing Dial, Payne-Gallwey Concentric Burners, Fletcher's Condensation Bulb „ Tubes . . Condenser Clamps ,, Stands „ Tubes, inner, Liebig's ,, outer, Liebig's ,, ,, Silica Condensers, Achromatic, Zeiss' . . Allihn's . . „ and Drying Oven Combined No. 6428 6406-6415, 6438-6439 1069 Aio6g 1401-1402 mo 2017 3496-3497 .. 815-816 660 372° 1441 3212 • • 3532-3533, 3538 Aplanatic, Zeiss' Cardioid „ Cribb's, Double Surface Double Surface Improved Flat Inner Tube . . for microscope for Reichert-Wollny Apparatus Fractional Distillation Graham's Habermann's Improved Form Inland Revenue King's College Pattern Liebig's New Form Paraboloid, Zeiss' Reflecting, Leitz's . . Soxhlet's Spiral Tube Fused to outer tube Spiral Worm ,, Storch's Swift's . . ,, with inside jacket Condensing Syringes, Brass Conductivity Cells Cones, Filter . . ,, ,, Porous ., Glass . . ,, Indiarubber for Gooch's Crucibles „ Seger Conical Flasks, Erlenmeyer's „ Measures Connections, Tube . . Constant Temperature Apparatus, Dupre's „ „ Drying Oven Containing Vessels for Sterilisers Cooling Apparatus, Dr. Savage's Copper Aspirators Basins Beakers Boxes for holding glass plates „ ,, sterilising Petri dishes ,, ,, ,, Pipettes Capsules for testing malt Condensers . . 2248, 2250 Crucibles 4319-4320 2214-2215, 3911-3915 3938-3939 2^30 2229 2387 1136-1137 2235 2475, 2476, 2479, 2480, 2486, 2487 1140 "44 2249-2250 2251-2252 2234 568 4936 2233 2243-2244 2255 2236 2238 2247 2228, 2253-2254 2239-2242 .. " 1143 1052-1063 2248 2237 2231-2232 2245 1404 2246 3710, 3711 5299 2679 2617 3636 2333 5492 2726-2728 3192 4311-4314 A 363 1, 63631 2500 • • 338-340 658 3732-3734 1961 1984-1990 441 • • 444-447 . . 440-448 2495 2253, 2255 2341 2252, Drying Ovens, Brazed, high temperature 2462, 2474 Copper Drying Ovens, hot air . . „ „ „ water „ ,, steam ,, Evaporating Baths Flasks Forcing Trays Funnels, hot water „ set of three Needle Stand . . Plate for drying micro slides Plates Retorts Rings, in sets Scoops Sieves Stand for drying micro slides ,, slides Steam Jacketed Pans Stills and Condensers Test Tube Stand Water Baths, Cylindrical form ,, ,, Electric . . „ „ for test tubes ,, ,, with constant level ,, ,, ,, porcelain cover Coram's Sulphuretted Hydrogen Apparatus Cord, Asbestos Cordite, Apparatus for testing Cutter ,, Sieves for testing ,, Mills for grinding Cork Borer Sharpener Borers Boring Apparatus Mats . . Pressers Rings Sheets, compressed Corks Asbestos Indiarubber Indiarubber, for milk tubes with boxwood tops Corlei's Flask Corn Balances ,, Sampler Cornet's Forceps Correction Tables for Pentane Lamps Corrosive Gas Analysers Counting Apparatus, Esmarch's ,, Neisser's Wolfhugel's Disc, Glass Squares, Cardboard Glass ,, Paper Cover Glass Gauge Cover Glasses, Graduated ,, Microscope Covers, Burette ,, Glass, for specimen jars .. ,, Glass, for beakers ,, Hemp, for gas cylinders „ Porcelain, for baths Craig's Lecture Apparatus Cream Tubes Cremometers, Chevalier's Cribb's Condensers Cross Staff Heads Crouch's Microscopes Crucible Drying Bath, Victor Meyer's 3373-3376- 3 1-5 14; CROSS STREET • HATTOTST GARDEN, E- C 1256 BAIRD &TATLOCK (LOM)ON) LTD. INDEX. Crucible Filler ,, Forceps „ Furnaces, various, ,, Jackets, Salamander ,, Skimmers Tongs, Gunmetal „ „ Iron . . Nickel ,, ,, with platinum points Crucibles, Battersea Link „ „ Triangle „ ,, Round ,, Cast Iron „ Coal-testing ,, for Copper . . „ Gold ,, ,, Iron Gooch's London round, Fireclay Meissen Porcelain Nickel Platinum Plumbago Rose's Royal Berlin Porcelain Salamander Silica Spun Copper ,, Iron Crum's Nitrometer Tubes Crusher, Bucking Board „ Hand „ Malt „ Simplex (for Ore) ,, Weatherhead Crystals, Models of Cubes, Specific Gravity Culture Apparatus, Novy's „ Bottles and Flasks, various „ Media „ ,, Trays ,, Troughs Cultures, Bacteriological Cupel Machines Moulds Tongs Trays Cupels, Bone Ash, Deleuil s "Mabor" Morganite Cupellation Furnace Cupboards, Apparatus. . ,, Fume Cups, Filtering, Rumpler's „ Ladling „ Suction . . Cutters, Cordite Filter Cuvettes, Glass Cylinder Covers, Hemp Stands Cylinders, Ammonia . . ,, Catheter Flugge's „ for microscopical work ., Glass, heavy Graduated, ist quality .. ,. 2nd „ Standard Lecture No. 6336 4274 2909-2912, 2920-2922, 2944- 2963, 2972-2991, 3000-3009 2338 6357-0358 4267-4270 4265-4266, 4274-4276 4271-4272 82383, C2383 6187 2335, 6182-6183 6178, 6179 2339 6188 6186 6184 6185 2332. 2682 2334, 6180-6181 2328 2336-2337 2342 6177 2329-2331 2327 6173-6176 2388-2391, 2416-2418, 2424 2341 234° 3599 6189 6190 3675 6192-6193 . . . . 6191 2321-2324 3870 544 • • 543-547 • • 539. 54° 406 537 A538 6201-6203 6198-6200 6375 6204 6195 6196 6197 6216-6217 124-128, 130-131 . . 113-118 2681 6260 2677 3637 2585, A2585 M43 3076 5088-3091 4758 3397-3399 5713 1444 719 3I7I-3I74. 5675 3175-3176 3169-317° 3369 2427-2414. Cylinders, Oxygen, &c. . . ,, Specimen ,, with loose drop-on lid Dabbers, Camel Hair . . . . Dairy Acidimeter . . . . ,, Analysis, Book of .. „ Thermometers .. .. Damp Chamber Slides. . Daniel's Hygrometer .. .. Dark Ground Condenser, Leitz's ,. ,. „ Swift's Davis' Flask . . . . . . Deflagrating Globes .. .. „ Spoons . . De Koninck's Absorption Apparatus Deleuil's Bone Ash Cupels . . Delisle's Potash Bulbs. . . . Demonstrating Rule, Faber's .. Demonstration Auxograph . . ,, Balances. . . Ocular, Leitz's . . ,, Rod . . . . Set of Thermometers Dennis' Lecture Apparatus Dennstedt's Furnaces . . . . ,, ,, Accessories for Density Rule and Scale of Hardness Dermatograph Pencils .. Desiccators, Triangular .. .. various forms .. Destructors, " Horsfall " . Determination of Tar Apparatus Detmer-Moore's Apparatus . Developing Dishes . . . . Dewar's Vacuum Vessels .. Diagnosis Outfits .. .. Diagnostic Outfit, Swift's .. .. Diagrammettes . . . . Diagrams, Anatomy Botany .. .. Physiological . . Plant Life . . . . Science . . . . . . showing classification of the elements to illustrate hygiene . . Dial Indicator Taps .. .. .. „ Rheostats . . . . . . ,, Thermometers .. .. .. Dials, Miner's . . . . . . Dialysers, Glass .. .. .. ,, Graham's . . . . . . ,, Sausage Skin .. .. Dialysing Filters .. .. .. Diamond Balance .. .. .. Mortars and Pestles . . . . Diamonds for Writing on Glass ,, Glaziers' . . . . . . Diamond's Filtering Flasks .. Diaphanometer, Konig . . . . Diaphanoscope, Lenarcie's ,, Vogel's . . . . Dibdin's Hand Photometer . . . . Differential Pressure of Blood Gas Apparatus Diffusion Bulb .. .. .. Shells .. .. .. Tube . . . . Digesters, Iron . . . . . . Steam .. .. . . 3067 21)8 . . 4080 4933*4934 t-n* 4126, en | 1440 . . 6l4O 1052-1063 . . 1404 . 3167 2355, 3025-3027 . . 4690 . . 3772 3214 . . 4493 1680, 1682 . 1050 '''Ml 2824-2835 2829-2865 . . 6161 2451 17811 _• (Nj -A 2 pm . . 4691 4518-4582 3737-3740, 3743 4340-4344 511-524 996 4 408-4 41.: (>003 6ooc. 6004-6008 . . - i'i'»4 532* 6404-6405 . 714-715 712 . 713 . 720-721 . 177.: <574-357<> -4-t'i . 2448 . . 5°34 . . 5663 . . 4844 . 788-789 . -H<> 7---v J44.i . 2447 .333- A 335 jCHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1257 BAIRD &. TATLOCK (LONDON) LTD. INDEX. Digestion Apparatus for Nitrogen Dilatometcr Dimenuon Thermometers Dip Electrodes Dipping Refractometers Disc Box for Photometer Discs, Calculating, Ackermann's Counting, Glass Filter, Glass ,, Porcelain Glass Indiarubber for bellows . . Pake's Enumerating Ihslies, Acid, Porcelain Developing for staining slides Nickel with cover Petri, various Photographic, Enamelled ,. Stoneware Platinum Roasting Sporulating, Glass . . • Stoneware for staining slides tetanus, Gabritschewsky's Tin, for weighing cream 1 >isinfectants Dispensing Balances . . . . 1 765 Scales Dissecting Forceps Instruments Knives Microscopes, Bausch & Lomb's ,, Leitz's „ Reichert's Sets, various „ Stage, Leitz's Trays, Glass Distillation Apparatus, for water analysis „ Mercury ., ,, Vacuum Bulbs, Gray's Tubes Tubes, Glynsky's . . Le Bel-Henninger's . . „ with trap „ „ Young's Distilled Water Bottles Distilling Bulbs Flasks Distributors. Gas Dittmar's Chlorine Apparatus . . ,, Gas Analysis Apparatus Potash Bulbs Divider, Ramsay's Dividing Machine Doremus' Ureometers Dornbush Spirit Lamp Double Aspirators, Glass Muencke's Bell Jars, Sach's Stirrer, Dupre's Surface Condensers Douche Vessels, Glass Doudney's Incubators Doulton's Filters Drainers, Filter, Porcelain Draining Boards Draining Tube Rack, Porcelain. . Drawer Handles Drawing Apparatus, Abbe No. 3653 5310 4188 53I3-53M 4944-4966 4820 4991 560 2587 2586 3"7, 3373-337° 2026 559 2439, 3053 3737-3740. 3743 594 5067 636-641, 651 374° 3737-3739 2350-2352 6329 648 586 652 4896 pages 1194-1195 1-1766, 1785-1787 1775 1560 AI544-I558 1523-1526 1321-1337, 4431 996-1003 1249-1251 1532-1544, 5671 1013-1014 34°7 5076 3812-3814 .-291-2295 3652 432i-A432i 4327 4326 3649-3651 4323-4325 2132-2134 3815 2739-2742 3543-3544 4043 4763-4765 3763 3118 3119-3121 -• 77°-773 3450 3736 3733-3734 1999 4009-4010 2249-2252 34'7 •• 311-314 . . 675-681 2712 129 3924 . . 274-286 . III-II2 No Drawing Apparatus, Bausch & Lomb's . . I35I"I355 „ Eyepiece, Leitz's . . . . . . 1035 „ Scale, Steel . . . . . . . . 3238 „ Table, Bernhard's . . 1141 Drechsel's Extraction Apparatus 2555 „ Gas Washing Bottles . . . . 4374 Dreyer's Thermostat . . 532 Drigalski-Conradi Media . . . . 540 Driving Wheels .. .. 5.291^5291 Drop Bottles, Chopping's 613 „ Schuster's .. .. .. 611-612 „ various .. 2099,2100,2103-2108 Drug Mill . . . . 3671 Drums, Recording . . . . . . 4495-44' Dryers, Filter Drying Apparatus for blood films . . 45' „ Taeuber's . . . . . . 2193 various, for gas .. 2193-2198 Walpole's . . 2196 ,, Chambers . . . . . . 2489-2490 ., Ovens and Condensers Combined 2475, 2476, 2479, 2480, 2486, 2487 ., Ovens, Brazed for High Temperatures 2462, 2474 Electric . . . . . . 2488 , Hot air . . . . 2454-2461 , ,, water . . . . 2463-2488 Steam . . . . . . 2477 Vacuum . . . . 5229-5232 ,, Paper, Botanical . . . . . . 4420 „ Stoves . . . . . . 2452-2453 ., Tube, Harcourt's . . . . . . 2194 Dubosq Colorimeters 5032-5033 Duclaux's Flasks . . . . . . . '. 549 Dumas' Vapour Density Bulbs . . . . . . 4346 Dumpy Levels 6398-6399 Dunstan & Dymond's Apparatus . . . . 3814 „ Shaker . . . . 3955 Dupre's Constant Temperature Apparatus A 3631, 63631 Heat Tester . . . . . . 3627-3620 „ Stirring Apparatus .. 4009-4010.5292-5293 Urea Apparatus . . . . 767 Dusters . . . . . . . . . . 4334 Dyer's Pans . . . . . . . . 1968 Dynamometer, Capillary, Haig's . . . . 7^7 .Earth Borers, American pattern . . . Frankel's „ ,. Gruner's . . . . - Orth's . . - - Earthenware Tile, Black and White . . . Ear Trough, Glass ..... . Edinger's Drawing Apparatus, Leitz's . . Edington's Staining Trough . . . . . Eggertz's Tubes .. .. .. Ehrlich's Apparatus for drying blood films „ Eyepiece . . . . ,, Salvarsan . . . . , . Eiloart's Models . . Einhorn's Saccharometer . . . . • Electric Blowers . . . . . . . Centrifuge, various patterns 880-883. Clocks .. .. .. 321 Drying Ovens . . . . 2464, 2488 Embedding Baths . . . . . - 388,397 Furnaces . . . . 2972-3016, 5647-5656 Lessing's . . . . 5^47-5656 Hot PJates . . . . . . 2530-2534 Kettle . . . . . . 364 Lamp, Nernst . . . . • • 463 . 5731 • 5729 573° . A63O . 34l8 1036-1045 . 600 3137-3138 45° 859, 1034 . 487 3557-35.58 : 78° . 2030 CROSS STREET • HATTCTN GARDE1ST, E- C BAIRD &TATLOCK (LONDON) LTD. INDEX. No. Electric Measuring Instruments . . 5318-5382 Motors . . . . 3969-3987 Pyrometers . . pages 979-1006 ; 5384-5606 Regulators . . . . . . . . 436-437 Serum Inspissators . . . . . . 379, 382 Signal Timing Clock . . . . . . 321-323 Sterilisers . . . . . . . . 359-363 Water Baths . . . . 2523-2525 Electrodes, Carbon, for Hoffmann's Apparatus . . 5936 DiP 5313-5314 Pipette . . . . . . 5315 Platinum . . . . 2368-2382, 5256 for Hoffmann's Apparatus 5935 A525& 5939-5942 2546-2547 6321 . . B5256 5254-5255.5260-5261 5248-5261 537'-5373 5990-5991 4724 5712 • • 385-399 1949 2513-2514 2066-2068, 2074-2077 374° 1950 1983 2786 3195 54° 3683, 3684 858 Zinc and Copper Electrolysis Apparatus Electrolytic Apparatus, Classen's Cells Electro-Magnetic Ore Separator Electrometer Key Tubes Electrometers, Capillary Electro-motor and Starter Resistance Elements, Specimens of Elliott's Gas Analysis Apparatus Elutriator, Hilgard's Embedding Baths, Paraffin Enamelled Cast Iron Basins Iron Water Baths . . Label Bottles Photographic Dishes Steel Basins ,, Beakers ,, Funnels „ Measures Endo's Fuchsine Media End Runner Mills Engel's Apparatus for Blood Engler's Models Oil Flask . . . . . . . . A2?42 Oil Distillation Apparatus . . . . 5031 Viscometers . . . . 5014-5015 Eng ish Bottles, " Winchester " series .. .. 2060 Filter Paper . . . . 2645, 2646, 62647, C2&47 Hand-made Bottles . . . . 2054-2055 Moulded „ . . . . ' . . 2056-2058 Thermometers .. .. 4084-4114 Entomological Apparatus . . . . . . 659-674 Pins . . . . . . . . 661 Entrican's Lymph-filling Machine . . . . 747 Epidiascopes, Leitz's . . . . . . 1077-1088 „ Zeiss' .. .. .. page 240; 1174 Erdmann's Burette Floats . . . . . . 3139 „ COa Apparatus .. .. 2171-2172 Erecting Prism, Leitz's .. .. .. 1051 Erlenmeyer's Flasks . . . . . . 2726-2728 „ Furnace for Benzoline . . . . 2822 „ Gas . . . . . . 2817 Esbach's Albumenometers . . . . . . 781-782 Esmarch's Counting Apparatus . . . . 558 Eternod's Plate . . . . . . . . 1437 Ether Bottles . . . . . . . . 2109 Ettling's Gas Pipette . . . . . . . . 4674 Eudiometer Stand .. .. .. .. 3147 Eudiometers, Bunsen's . . . . . . 3143 „ Cavendish . . . . . . 3145 ,, Lecture . . . . . . 3146 Ure's .. .. .. .. 3144 Evaporating Apparatus, Vacuum . . 2293-2295 ,, Baths, Copper . . . . 2496-2499 Exhaust Pump . . . . . . . . 707 Exhausting Syringes .. .. .. 3709,3711 .,-"1 5)18-5384 Experimental Malt Kiln Experiments on Plants Apparatus Exploding Bottle Bulbs Tubes Explorer's Mineral Cabinet . . . . 6296 .(explosion Pipettes, Hempel's . . 4673, 4675, 4678-4679 Extraction Apparatus, Bolton & Revis' . . . . 2558 Clayton, Beadle & Stevens A2J57 Drechsel's . . . . 2555 Greiner & Friedrich's . . A 2555 New pattern . . 2557 Soxhlet's . . 2548-2554 Thimbles, C. S. & S. . . . . 2556 Extractors, Meat . . . . . . . . 574-575 Eye, Models of .. .. .. <>oi|-.\6oi6 Eyepieces, Bausch & Lomb's . . 1344 Compensating, Leitz's looy-AioOy „ Swift's . . 1401-1402 Zeiss' . . . . 1 1 10 leiirlich's . . . . . . 859, 1034 Huyghgnian, Leitz's . . . . 1067 „ Swift's. . . . . . 1403 ,, Zeiss' . . . . . . 1109 Leitz's .. •.. 1021-1022, 1027-1035 Reichert's, various .. .. 1252-1260 Eye Protectors . . . . 620 , Faber's Calculating Rules Faija's Apparatus for cement „ Cement Gauger ,, Hopper Farination Apparatus, Grobecker's Farmer's Gas Calculator 3208-3211, 3213, 3214 5<>9I 5090 5092 5669 4760 Fat Extraction Apparatus, Bolton & Revis' 2558 Clayton, Beadle & Stevens .^2557 Drechsel's G. & F.'s New pattern Soxhlet's Thimbles, C. S. & S. Fermentation Saccharometer Vessel, Kuhne's (Plants) Fertilisers Fery Pyrometers, Radiation ,, „ Spiral Fibre, Silica Filar Micrometer, Bausch & Lomb's File Handles Files, Flat „ Round ,, Triangular Film Spreaders ,, Weight, Perforated Filter Cases, Japanned Tin Cones, Paper ,, Platinum ,, Porous . . Cutters Discs, Glass „ Porcelain Drainers, „ Dryers Hats Paper, Chardin's „ Clippings „ C. S. & S. „ English . . „ ' French grey 2555 • A2555 2557 2548-2554 2556 774 4564 1234 5603-5605 5606 2402 '350 2582 2580-2581, 6212-6213 2576-2577, 6208-6209 2578-2579, 6210-6211 1517-1518 3741 2583-2584 2679 2349 2617 2585^2585 2587 2586 2712 2588 2680 2619-2621 2666 2648-2681 2645, 2646, 62647, €2647 2640 ICHEMICAL AND SCIENTIFICAPPARATUS AND PURE CHEMICALS. 1259 BAIRD &TATLOCK (LONDON) LTD. INDEX. Filter Paper, German . . Swedish (Muencktel's) „ Presses Pumps, Arzberger & Zulkowsky's . . Brass Bunsen's Fischer's Glass . . 3686 Kortings New form Starkey's Rings with arms Stands .. -. 3882 Tubes, Soxhlet's ,, stoppered Filtering Apparatus, Berkefeld Cobbett's .. Gibson's . . Massen's . . Novy's Witt's „ Cups, Rumpler's „ Flasks, Diamond's ,, heavy glass widened neck . . ,, ,, with stopcock Filters, Balloon, porous Berkefeld „ Chamberland's Dialysing ,, Doulton's Houston's ,, Kitasato's „ Klein's Lazarus-Barlow's ,, Massen's Paine's Pake's ,, Reichel's Filtrate Jars . . Finckner's Bunsen Burners Fine Adjustment Valves Fireclay Burners ,, Channel Pipes ,, Combustion Boats Crucibles ,, triangular Muffles Retorts Sinks Traps Troughs ,. ,, for holding cultures Fischer's Calorimeter . . „ Filter Pumps Fitzroy's Barometers Flame Steadiers Flash Point Apparatus, Abel's Abel-Pensky ,, ,, ,, Gray's ,, ,, ,, Pensky-Marten's Flask Guards Flasks, Anschiitz „ Assay, Bohemian glass . . „ „ Resistance „ . . Beaker Beer Bohemian Glass Bolt Heads Cement, Stanger & Blount's No. 2647, A2647 2641. 62644 2685-2702 3686 3689-3694 3687 3698-3699 •3688, 3695-3700 3692-3693 3700 3694 2614-2615 .3885, 3887-3890 2713 2714 696-705 .. 687-688 2703-2711 t-86 . . 693-694 2683 2681 2722 2720 2721 2684 2618 706 . . 683-684 . . 720-721 . . 675-681 . . 708-709 682 .. 685,695 711 689 692 710 . . 690-691 3377 35°3 3081-3082, 3092 2883-2884 . . 17 5-20 7 3775 6178-6186 2334. 2335. , 6182 6314 3804-3805 "9, 135-174 152 2881-2882 537 5630 3698-3699 6064-6065 5001-5003 5005-65006 5004 2543 2302-2303 2733 2732 1981 2265 2715, 2730 2729 5215 «^^ NL. Flasks, Cement, Leipper's . . 5216 „ Conical, Erlenmeyer's . . 2726-2728 „ Copper . . 2745-2747 „ Corleis' . . • • - . 4698 ,, Davis's . . . . 3167 Distillation . . . . 2296, 2739-62742 ,, ' Dnclaux's . . . . 549 Engler's . . - . A2742 ,, Erlenmeyer's Bohemian Glass . . 2726 „ ,, Jena ,, . . . . 2728 „ ,, Resistance ,, . . . . 2727 Filtering • • 2684, 2720-2721 ,, ,, Diamond's . . . . . . 2722 „ with stopcock . . . . . . 2684 ,, for Cultures, various . . . . 543-547 for fat extraction . . 2737-2738 „ ,, fractional distillation . . 2296, 2739-62742 „ for water conductivity experiments . . 5298 „ Giles' pattern . . 3163 ,, glass, various . . . . 2715-2742 ,, Globular . . . . . . 2729 Graduated, 2nd quality 3161-3162 ,, ,, Standard .. .. 3152-3153 Stoppered .. 3152,3159-3160,3165 „ ,, Unstoppered 3153, 3154-3158, 3164, 3167 Jena Glass . . . . . . 2718-2719 Kjeldahl's 2735-2736 „ Lister's . . . . 541 „ Oil Testing . . 3166. 5°52 „ Oxygen . . . . 2730 ,, Parting, stoppered 2734 ,, Pasteur's .. . . 536, 548, 550, 551 ,, Porcelain . . . . 2743 Resistance Glass .. .. 2716-2717,5298 ,, Roscoe & Lunt's 553 ,, Sarnstrom's . . . . . . 4699 Schimmel's . . . . . . . . 62742 „ Serum .. .. •• 2114-2115 Silica . . . . - - 2392-2394 Silver.. .. .. .. .. 2256 Sutherland's . . . . . . . . 3168 „ Washing . . 2723-2725 ,, Water conductivity . . . . . . 5298 " Wine " . . . . • • 542, 2266, 2748 with mark on neck, 2nd quality . . 3IDI. 3102 ,, ,, standard . . 3152-3153 ,, stoppered 3I59-3100. 3l65 ,, ,, unstoppered. . platinum electrodes three necks Woodheads Yeast, various Flat 6ottles, Soyka'e Files Flattening Mills Fleischl's Haemoglobinometer ,, ,, Meischer's Modification Fletcher's Anemometer Argand Burners Automatic Blowpipe Blowpipes Burner, with hood for soldering Compound Blowpipe Concentric Burners . . Furnaces, various Gas Pressure Governors High Power Burners Instantaneous Water Heaters Muffle Furnaces Oxygen Blowpipe Radial Burners . . . . 3525 5938 2767 552 5°3-5°5 724-725 2580-2581, 6212-6213 6265-6269 . . 862-865 866 1903 3527-3528 2019 2017-3022 3843 2017 3532-3533 2888, 2903, 2944-2971 3539-3542 3538 3534-3537 6227-6229 2018 3529-3531 CROSS STREET • HATTON GARDEN, E-C 1260 BAIRD 46 3362 3363 3366-3428 599 3414-3416 3366-3382 337°-337« 3372. 3379, 338o 3378 3422-3424 3382 2126 4989-4990 3116 3HO ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. :r^£y BAIRD & TATLOCK (LONDON) LTD. INDEX Jena C.lass Basins Beakers Bottles Flasks .. 2718, Retorts Test Tubes Jets, Burette Johnson's Combined Album-Press Johnston's Illustrations of Chemistry „ Picro-Saccharometer Jolly's Spring Balance Jones' CO, Apparatus „ Opacity Meter Jugs, Acid, Gutta Percha „ „ Stoneware.. „ Graduated Ladling Jung's Microtome Knives „ Microtomes Junker's Calorimeter .. K Kali Bottles . . . . . . . . Kekule Apparatus . . Kettle, Copper, for jnelting paraffin wax „ Electric . . . . . . „ Soxhlet, for sterilising milk . . Key Switches . . . . . . Keys, Electrometer . . . . . . ,, for gas cylinders .. .. Killing Box, Zinc . . . . . . Kipp's Chlorine Apparatus . . . . Sulphuretted Hydrogen Apparatus No. 1960 •• 1973,1976,1977 2069 2719, 2728, 2735, 2738 3794-3796 4065-4066 3140-314! 4419 5983 769 1773 2174 3685 2137 2136 Kirchhoff & Bunsen Spectroscope Kirkby-Gutzeit Arsenic Apparatus Kitasato's Filter Tubes Kjeldahl's Apparatus . . , , Flasks Klein's Bacteriological Case of Pipettes Filters ,, Meat Extractor ,, Pipettes Klinostats Knapp's Ophthalmatrope Kneading Machines Knives, Cartilege Dissecting Glass Tube Cutting Microtome, English „ Jung's ,, Thoma's Knop's Soil-testing Apparatus . . Koch's Hypodermic Syringes ,, Steam Sterilisers Kohlrausch's Cells „ Universal Bridge . . „ Wheel Bridge Konig's Diaphanometer Koninck's HSS Apparatus Korting's Filter Pumps Kossel's Sodium Press Kronecker's Blood Gas Apparatus Kuhlmann's Balance Kuhne's Fermentation Vessel . . Kunkler's Viscometer . . L Moulds Labels, Bacteriological 53°3 6262 1616, 1636-1638 1602-1605 5644 . . 2081 . . 5974 . . 405 . . 364 . . 365 5362-5365, A5368 . . 85256 3°77-3°78 . . 666 . . 4°43 4°44 5766-5769, 5790-5791 1909 682 3639-3648 2735-2736 798 . . 685, 695 574 798 4499-4503 . . B6oi6 3655-365? 1526 1523-1525 3433-3435 1639 1616, 1636-1638 1617 57°9 471 •• 343-346 53°5, 53°8, 53°9 5344-5345 5326-5327 5°34 4042 3692-3693 3841 3582 1708 4564 5016 1562-1563 1531 Nr>. 3438^3438 3440^3441 3436-3437 3439 3442 . . 100-112 2021 4938 726 6270-6273 2685-2702 . . 696-706 . . 685, 695 692 100-293 3098-3100 4801-4805 4774-48o° 2627-2630, 2635^2635 726 3754 Labels, Bacteriological, book form „ for microscope slides „ „ reagents, book form . . „ ,, in boxes . . „ plain, with border Laboratory Benches . . ,, Blowpipes Book on Dairy Analysis Buckets „ Crushers and Grinders „ Filter Presses „ Filters, Berkefeld's ,, „ Klein's ,, ,, Paine's Fittings .. ,, Gas Plant „ Governors „ Meters „ Note-books Pails ,, Press, Small „ Shaker, Dunstan & Dymond's . . 3955 Sinks .. . . .. 119, 135-1/4 „ Stools . . . . . . . . 132-134 „ Truck .. .. .. .. A 1 29 Lactometers . . . . . . 4925-4927, 4930-4.132 „ Soxhlet's . . . . . . 493 1 „ Veith's Ladles . . . . . . 6263 Ladling Cups .. .. .. .. .. 6260 „ Jugs . . . . . . . . . . 6262 Laker's Puncturing Apparatus Lamp Holder for Photometer . . . . . . 4^37 „ Resistance . . . . . . . . 5346 „ Screen, Stoneware ,, Spinners . . . . . . 483.5 Lamps, Benzoline, Adjustable Burner . . 3466-3469 ,, Vertical Burner . . 3464-3465 Formalin . . . . . . . . 737-738 Mercury, Zeiss' .. .. 1150-1151 Microscope . . . . . . . . 461-468 Nernst, Zeiss' .. .. .. 1147-1148 Oil . . .. .. .. 6161 Pentane . . . . . . 4826-4830 Polariscope . . . . . . 5855 Spirit, and Bunsen Burner Combined 347°-3473 Berzelius' . . . . . . 3449 Brass . . . . 3459 Dornbush's . . . . . . 345° Lang's .. .. .. 3447 Luhme's .. .. 345I-3452 with brass wick holder . . . . 3443 „ porcelain wick holders . . 3444 „ side tubulure Land Chains . . . . . . . . 6444-0457 Lang's Benzene Model . . . . . . 3.VJ° „ Spirit Lamp . . . . . . 3447 Lanterns, Science . . . . . . 384 1 Lassar's Microscope Lamps . . . . . . 461-462 Laurent's Polariscopes . . . . 5888-5906 Lazarus-Barlow's Osmometer Tubes Pressure Filter Leach & Lythgoe's Refractometer Scale Lead Apparatus for HF. . . . . 1966-1967 ,, Basins . . . . . . . . . . 1965 „ Seals . . . . . . . . . . 6346 Leaf Cutter or Punch .. .. .. .. 11"! Le Bel-Henninger's Distillation tubes Le Chatelier Gauge Lecture Balances . . . . . . 1677, 1680 „ Blackboards . . . . 122-123 CROSS STRET • HATTOTST GARDETST, E-C 1266 BAIRD &TATLOCK (LONDON) LTD. INDEX. Lecture Cylinders Demonstration Set, Silica Diagrams Eudiometer Furnace Tables Leffmann-Beam Machines Lcipper's Cement Flask Leitz's Combination Lens „ Condensers „ Drawing and Projection Apparatus ,, Epidiascope „ Erecting Prism .. Eyepieces, Compensating „ ,, Demonstration ,, ,, Drawing „ „ Huyghenian . . ,, „ Micrometer . . „ Mechanical Stage „ Microscopes and Accessories „ Microsummars . . „ Microtome, Bardeen Hand ,, Object Marker .. „ Objectives, Achromatic . . ,, ,, Apochromatic „ „ Fluorite „ Polarising Apparatus ,, Photo-Micrographic Apparatus „ Reflecting Condensers „ Selenite and Mica Films . . „ Universal Projection Apparatus Lenarcie's Diaphanoscope Lennox Blowers Lens Holders, Leitz's .. ... „ Stands . . „ ,, Bausch & Lomb's Lenses, Coddington „ Combination, Leitz's Focostat various Lessing's Electric Furnace Lett's Absorbing Vessel Leunig's Micrometer Paper Scales Testing and Registering Apparatus Levelling Stand Table Levels, Dumpy or Gravatt's Pocket Reflecting, Locke's No. 3369 5980-6013 3146 2959-2963 . . 107, 108 „ Spirit „ ,, circular „ straight „ Y, improved Lever Balances ,, Switches Levers, Recording Liebig's Condensers „ Furnace Potash Bulbs Lifters, Section Liyht Screens Lignum Vita? Gratings for Sinks . . Lister and Babcock Milk Testing Machine Lister's Flasks Lithanode Batteries Locke's Reflecting Levels Locks, various Lohnstein's Fermentation Saccharometer Lothar Meyer's Air Bath „ „ Embedding Bath 5216 1065 1052-1063 1036-1045 1077-1088 1051 io6g-Aio69 1050 l°35 1067 1027-1033 1023-1026 . . 914-1088 1070 1640 1643 1049 1064 1068 1066 1046-1047 1071-1075 1052-1063 1048 1077-1088 5664 2029-2030 1015-1016 4430 1319-1320 563, 4428 1065 .. A44i4 561-567, 4428, 6251-6254 5647-5656 5081 5247 5246 5243, 5245 493 6388 6398-6399 6425-6426 495-496, 6385-6387, 6389 495-496, 3255, 6389 • • 3254. 6385-6387 6400-6403 1770-1771 5366-5368 . . 4498, A4498, 4502 2228-2230, 2253-2254 2821 3763-3764 1488-1491 4505-4506 144 4897-4905 541 5377 6425-6426 . . 287-289 774 2456 391 So. Lothar Meyer's Furnace . , . . . . 2885 .. „ Receiver . . . . . . 2299 Lovibond's Tintometer Sets . . . . 4210-4263 Low's Chemical Lecture Charts . . . . 5980-5982 Lowry's Gas Regulators . . . . . . 435-437 ,, Thermostat . . . . . . . . 5285 Luhme Spirit Lamps .. .. .. it'>I-3542 Luminous Burner . . . . . . . . 3509 Lummer-Brodhun Box Photometers . . 4845-4846 Lumsden's Balances . . . . . . . . 1676 Lunge & Rey's Pipette . . . . . . 3868 & Zeckendorf's Air Tester . . . . 4681 Lunge's Gas Volumeters . . . . 3605-3610 „ Nitrometers .. 3600-3602,3605-3610,3613-3614 Lux's Gas Balance . . . . . . . . 4748 Lymph Forceps . . . . . . . . 757 Machine for filling tubes . . . . 746 „ „ „ „ Entrican's . . 747 ,, „ preparation of . . . . 742-745 Spoons, Vqlkmann's . . . . . . 756 Tubes . . . . . . . . 748 Vessels . . . . . . . . 750-753 Lymphometer and Haemacytometer combined .. 811 M Mabor Cupels . . . . . . . . 6196 M'Conkey's Bile Salt Media . . . . . . 540 Macfarlane & Caldwell's Gas Analysis Apparatus 4711-4712 Machines, Cement Testing . . . . 5095-5209 Centrifugal, various . . 876-904, 4871-4897 Clover Testing . . . . . . 5702 Cupel . . . . . . 6201-6203 Dividing .. .. .. 3119-3121 for boring corks . . . . . . 2315 „ filling lymph tubes . . . . 746 „ „ ,, tubes, Entrican's . . 747 ,, preparation of animal lymph . . 742-745 ,, testing metals . . . . . . 3677 Gerber's . . . . • . . . . 4885 Ice Making, Raplin . . . . . . 3704 „ shaving . . . . . . 3658 Kneading . . . . . . 3655-3657 Leffmann-Beam, Centrifugal . . 4871-4884 Lymph, for preparation of .. .. 742-745 Mincing, various . . . . . . 569-571 Mixing . . . . . . 3655-3657 Polishing . . . . . . 3678, 3679,3681 Shaking .. .. .. 3955-396? „ Chopping's . . . . . . 905-907 Mach's Cedarwood Oil Bottles . . . . . . 2096 Mackey's Cloth Oil Tester .. .. 5048-5051 Maercker's Mills . . . . . . 3664-3665 Magnalium Balances .. .. .. 1671-1672,1688 Magnets, Horseshoe . . . . . . 6255-6256 Magnifiers, Bausch & Lomb .. .. 1290-1317 „ Binocular, Zeiss' .. .. 1152-1155, 1158 ,, Thermometer .. .. .. 5317 ,, various . . . . . . . . 561-567 Mahler's Bomb Calorimeter . . . . . . 5645 Mallets . . . . . . . . 2598, 6257 Malt Crusher . . . . . . . . 3675 ,, Kiln, Frew's . . . . . . . . 5704 „ Kiln Thermometers .. 4167-4169,4195-4196 „ Mills . . . . . . . . 3669, 3670, 3674 „ Seck's . . . . . . 3672, 3673, 3676 Manley's Alcoholometer . . . . . . 2257 Mann's Cement Testing Apparatus .. .. 5217 Manometer Tubing, Glass . . . . . . 3111 Manometers, Compressed Air, Oliver's .. .. 815-816 „ Root .. .. .. .. 4514 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- BAIRD &TATLOCK (LONDON) LTD. INDEX. Manometers, various Mansfield's Oil Gas Plant Marcband's Calcium Chloride Tubes Milk Tester Marine Barometer Marsh's Arsenic Apparatus Marshall's Bunsen Burners Martin's Centrifuge, Electric Water Mashing Baths Mash Tun Thermometers Mason's Hygrometers Massen's Filters Maste's Argand Burner Mats, Absorption „ Cork .. ,, Indiarubber Maximum & Minimum Thermometers Mayer's Dissecting Microscope . . McLeod Vacuum Gauge Mead's Adhesive Rubber Plaster Measures, Acid, Automatic Bell-Shape Boxwood Conical Cylindrical Enamelled Steel Spring, Steel Steel Meat Compressors „ Presses Mechanical Mortar and Pestle . . Stage, Bausch & Lomb's „ Leitz's „ Reichert's „ Swift's „ Zeiss' Media Culture Medical Centrifuge, Hand „ „ Water „ Specimens Meischer's Haemacytometer Meissen Porcelain Basins „ ,, Capsules ,, .- Crucibles Meker Burners „ Furnaces Melting Point Apparatus, Roth's Ubbelohde's .. ., ,, ,, various Mercury Air Pumps . . . . 3577-3580, „ Assay Apparatus, Holloway's . . Bottles, Glass . . .. „ Iron . . ,, ,, Stoneware „ Distillation Apparatus .. Retorts „ Gasometer, Hempel's . . .. ,, Stead's ,, Gauges „ Lamps, Zeiss' ,, Pumps, Adeney's „ Buckmaster & Gardner's .. .. Friedrich's „ Reservoirs „ Steel Thermometer „ Toluol Gas Regulator Tongs ,, Troughs Metal Baskets for holding test tubes No. 2279-2289 3098-3100 . . 2182 4922 1937 1905 3475. 3476 ASgi-FSgi . . 884-891 2492-2494 4166 4151-4159, 6124-6128 . . 686, 689 35M 4206 395° M53 . . 4160-4167, 4187, 6143-6146 1150-1173 3580 758 4915-4916 3189, 3192 3218-3227 3192 .. 3169-3176, 3191 3J95 3246-3249 .. 3228-3232, 3237 1441 • • 572-575 3682 1342 1023-1026 . . 1209, 1244-1245 1384, 1385, 1388, 1391 1126-1128 539-54° . . 876-878 879 576 . . 860-861 . . 1946 2325 2328 3493-3497 2909-2925 2773 2775-2778 2773-2780 3585-3591 6258 2IO2 2139 2IOI 3812-3814 3802-3803 3°49 3°33 2283-2285 1150-1151 5087-5089 • A3588 3588 3592 5493 432 4273 3757-3759, 5270-5271 438-439,442 Metal Boxes for CO2 . . ,, ,, holding glass plates ,, ,, sterilising pipettes ,, Glass Bottom Rods for making platinum loops Saccharometers Tubes, collapsible Meteorological Instruments Meters, Laboratory „ Pigmentation Methylated Spirit Blowpipe Meyer's Apparatus ,. Funnels „ Vapour Density Apparatus Mica Chimneys Mice Glasses Micro-Balance, Nernst „ Metallograph, Leitz's „ Nernst Lamp „ Telescope for botanical work Micrometer Eyepieces, Leitz's . . Leunig's Oculars, Zeiss Microscope Accessories, Leitz's . . „ Swift's . . ,, Zeiss' Cabinet, Dr. Rees' . . Condenser Cover Glasses „ ,, Graduated Dyes Lamps Needles Slide Benches Boxes Cabinets Heaters Jars Labels Rings, Aluminium ,, Glass Stand Trays Troughs, Glass „ Porcelain Slides Warm Stage Microscopes, B. and T. Models . . ,, Bausch & Lomb ,, Crouch's ,, Horizontal Reading ,, Leitz's ,, Reichert's Swift's . . „ Watson's, B. and T. Model Zeiss' Microsummars, Leitz's Microtome Accessories 1569-1576, Blades ,, Knives, English ,, Jung's ,, ,, Thoma's ,, Razor Microtomes, Bardeen, Leitz's ,, Becker's . . ,, Cambridge rocking ,, „ sliding . . ,, Cathcart's ,, Demonstrator's „ Freezing, Becker's . . „ Jung's 30 441 440 671 1506 3300-335° • • 754 6050-6151 4774-4800 4227 2016 4328-4329 2787 4361 456 . . 488-489 • • 979-995 1147 4414 1027-1033 5247 1113-1121 1004-1088 1398-1411 1107-1141 657 568 1420-1421 1422 pages 1189-1193 . . 461-468 1507-1510 . . 490-491 1462-1467 1461-1484 579-582, 1456 607 3440, A344I 145° 492 1468-1471 589-596, 598 .. 583-584 1423-1449 M55 1356-1371 1264-1289 1192-1207 3066 914-1088 1208-1263 1356-1371 1089-1106 1070 1580-1585, 1589-1596 1565-1049 1639 1616, 1636-1638 1617, 1632-1635 1598 1640 1618-1631 1568, 1588 1561, 1564 1641-1642 1618-1631 1602-1605 if] 14 -CROSS STREET • HATTO>T GARDEN, E- C 1268 INDEX. Microtomes, Leitz's . . . . . . Minot's .. .. .. „ rotary . . . . Reichert's . . . . Schanze's . . . . Students' . . . . Swift's . . . . . . Williams' . . . . Milk Apparatus, Houston's . . . . ,, litmus media . . . . . . „ Pipette . . . . . . „ Sterilisers, Soxhlet's . . . . ,, Tester, Marchand's . . . . ,, Testing Machine, Gerber's .. ,, ,, „ Lister & Babcock's Millboard, Asbestos . . . . . . Mills, Analytical . . . . . . „ Ball . . . . . . . . „ Bark, Drugs, etc . . . . „ Cordite . . . . . . End Runner . . . . . . Flattening . . . . . . Maercker's . . . . . . Malt . . _ . . . . . . ,, Seck's . . . . . . Sugar . . . . . . . . Table . . . . . . . . Mincing Machines, various . . . . Mineral Cabinet . . . . . . Minerals for Analysis . . . . . . „ in sets . . . . . . Miners' Dials . . . . . . ,, Horns . . . . . . ,, Prospecting Pick . . . . „ Vanning Shovel . . . . Minim Measures .. .. .. Minot's Microtomes . . . . 1610 „ Watch Glasses, solid .. .. Mirror Glass Scales . . . . . . Mittens, Indiarubber . . . . . . Mixing Machines . . . . . . ,, Pans . . . . . . Models, Anatomical . . . . . . ,, Botanical . . . . . . Collie's .. .. .. Eiloart's .. .. „ Engler's . . . . . . Lang's . . . . . . „ of Bees . . . . . . Bramah Press . . . . Crystals, Glass . . . . „ Wood . . . . Eye . . . . . . Honeycomb . . . . Pumps . . . . . . Ram . . . . . . ,, Perkin and Kipping's . . . . ,, to Demonstrate Hygiene . . Mohr's Burettes with Enamelled Band .. „ ,, „ Jet and Pinchcock „ „ „ Patent Stopcock „ „ ,, Side Stopcock . . ,, ,, ,, Stopcock . . ,, Clips . . . . . . ,, Potash Bulbs . . . . „ Specific Gravity balance .. „ Still Watcher . . . . Moist Chambers for hanging drops . . ,, ,, Geissler-Klebs . . ,, ,, Geissler-Recklinghausen „ „ Schulze's . . . . No. 1640, 1643 1610-16:4 1644-1649 1607-1609 1641-1642 . . 1567 . . 1566 4939^4943 . . 540 . . 4928 . . 365 . . 4922 .. 4885 4897-4905 3545-3546 . . 3667 3659-3663 . . 3671 3632^3634 3683, 3684 6265-6269 3664-3665 3669-3670, 3674 3672-3673, 3676 . . 3666 . . 3668 . . 569-571 . . 6296 page 1239 6276-6296 6404-6405 6234-6237 . . 6275 6274, A6274 .. 3188 -1614, 1644-1649 .. 645 . . 3243 . . 6249 3655-3657 . . 1969 6017-6046 4585-4656 .. 3559 3557-3558 . . 3561 . . 3560 4658-4659 3786-3788 . . 2321 2322-2324 6oi4-A6oi6 . . 4657 3776-3790 . . 3790 3562-3564 . . 5995 3130-3131 . . 3127 . . 3132 . . 3133 . . 3126 2203-2206 3765-3766, 3769 .. 1758 . . 2304 . . 1451 . . M45 . . 1446 . . 1452 Moisture Tester, Brown & Duvel's Morgan-Harvey Furnace Morgan's Plumbago Crucibles . . ,, Salamander Crucibles Morganite Cu|" Morochowetz Dialysing Filters . . Morphia Assay Bottle Mortars for Quartz Iron, flat bottom Ross's Amalgam, Buck's and Pestles, Agate Diamond . . Glass Iron Mechanical Porcelain . . Wedgwood Mosquito Outfits Motor and Starter Resistance . . Motor Starters * Motors, Electric ,, Hot Air, Henrici's ,, ,, Robinson „ Water, Thirlmere Moulds, Button Cupel for Metal Rods „ Ingot L .. Mountain Barometer Mounting Paper, Botanical Mouth Blowpipes Muencke's Aspirators . . „ Gas Washing Bottles Muencktell's Swedish Filter Paper Muffle Furnaces, various 2900-2971, Muffles, Fireclay ,, Nickel „ Platinum Silica Muscle Chamber Museum Bottles with metal screw cap „ Cases „ " Jars Muter's Carbolimeter . . „ Tubes N 5703 -16221 0177 6171 6197 720 3205 6298 6299 .. B6i52 6297 3568 3574-3576 3573 • 3565-3567, 6299 3682 3570-357* 3569 659 537'-5373 3988-4000 3969-3987 908-909, 2031-2032 .. 911-913 910 6198-6200 6316 6300-6313 1562-1563 1931,6096 4421 2001-2009 3733-3734 4375 2641-62644 3011-3012, 6215-6229 6314 6315 2363 2426 791 3426 124-128, 130, 131 3366-3428 3253 3251-3252 800 4131,4199 540 5°93 1511-1512, 1514-1515 Nabarro's Pipette Naphtha Thermometers Nasgar Culture Media Needle Apparatus for Cement . . ,, Holders „ Stand, Copper ,, Sterilising Box . . . . . . 628 Needles for Hypodermic Syringes . . 477, 478, 480 ,, Microscope .. .. .. 1507-1510 „ „ Platinum Indium .. .. 151? Steel .. .. .. .. 1516 „ Test, Gold . . . . . . . . 6368 Vicat's .. .. .. 5188-5189 „ weighted, for Cement .. .. .. 5187 Negretti & Zambra's Horticultural Hygrometer . . 6139 Neisser's Counting Apparatus, Leitz's ; .. 1011-1012 Nelson-DaUinger Microscope Lamps . . . . 466-467 Neosalvarsan Apparatus . . . . . . 487 Nernst Electric Lamp . . . . . . . . 463 „ Lamps, Zeiss' .. .. .. 1147-1148 „ Micro-Balance . . . . . . Nesslerising Tubes .. .. .. 3196-3204 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1269 INDEX. Nets, Folding, Pocket . . „ for Bellows „ Sugaring „ Telescopic Nicholson's Hydrometers Nickel Basins „ „ Scheibler's „ Capsules for Milk Analysis „ Crucible and Lids „ Crucibles Tongs „ Dish with Cover „ Muffles „ Spatulas „ Wire .. ,, Wire Gauze Nickel-Chrome Wire Triangles . . Nicol's Specific Gravity Tubes . . Nitrogen Apparatus „ „ Schwarz's . . „ Bulbs, Fresenius' ,, ,, Volhard's „ „ Will & Varrentrap's ,, ,, with Funnel „ Tetroxide Apparatus . . Nitro-glycerine Apparatus Nitrometer Clamps „ Tubes, Crum's Nitrometers, Allen's „ Horn's „ Lunge's . . 3600-3602, „ Schiff s . . „ Tennant's Nobbe's Clover Sampler ,, Corn Sampler. . „ Separator Nosepieces, Bausch & Lomb's . . „ Leitz's „ Reichert's Swift's „ Zeiss' Novy's Culture Apparatus „ „ Bottles „ Filtering Apparatus „ Thermo-Regulators Nuttall's Incubator Object Marker, Leitz's Objective Changer, Zeiss' • Objectives, Achromatic, Leitz's „ „ Reichert's » » Swift's . . » „ Zeiss' „ Apochromatic, Leitz's ,, ,, Reichert's ,, ,, Swift's „ „ Zeiss' „ Fluorite, Leitz's Oculars, Bausch & Lomb's ,, Compensating, Reichert's Swift's . . .. Demonstration, Leitz's ,. Huyghenian, Reichert's •< ,, Swift's . . Zeiss' „ Micrometer, Zeiss' .. Projection, Reichert's . . „ Revolving, Reichert's . . , Spectroscopic ,, Odourless HjS. Apparatus No. .. 662-663 2027 665 664 3356-3358 1958 1951 2506 2336-2337 4271-4272 5007 6315 3831-3833 4384 4385 A4284 3872 3639-3648 3598 3596 3595 3593 3594 4693 3615-3623 2222 3599 3603 3604 3605-3610, 3613-3614 3597 3611-3612 569° 5691 5670 1338-1341 1017-1019 1261-1263 1398 1129-1131 544 543 .. 693-694 •• 43J-432 324 1049 1132-1135 1064 1253 1400 1108 1068 "54 1399 1107 1066 1343-1344 1255 1401-1402 1050 1252 1403 1109 1113-1121 1256-1257 1259-1260 1258 A4O4O Oertling's'Balances, Assay „ ,, Bullion ,, ,, Chemical ,, Weights Oil Burners, paraffin . . „ Distillation Apparatus, Engler's „ Flash Point Apparatus, Abel's „ ,, Abel-Pensky No. I739-I747. I749-I75I 1 752-1 756 1708, 1711-1721 1808-1818, 1831-1842, 1865 3460 Gray's Pensky-Marten's Flasks Engler's Schimmel's . . ,, for Air Pumps ,, ,, Oleorefractometer ,, Furnaces . . ,, ,, Fletcher's. . „ Gas Plant, Mansfield's ,, Stoves ,, ,, Petroleum . . ,, Testers, Mackey's ,, ,, Thurston's ,, Thermometers „ Vapour and Gas Detector . . ,, Viscosity Apparatus, Coleman-Archbutt's „ „ „ Engler's ,, „ ,, Kunkler's ,, ,, ,, Redwood's Oleometers Oleorefractometer, Jean's Olivers' Clinical Manometer „ Haemacytometer ,, Haemodynometer „ Haemoglobinometers ... Opacity Meter, Jones' Opal Glass Scales Ophthalmatrope, Knapp's Opisometer Opsonic Incubator Pipettes Optical Projection Screens Ore Crushers ,, Separator, electro-magnetic Orsat's Gas Analysis Apparatus 4993-5ooo 5001-5003 5005-65006 5004 3166, 5052 . . A2742 82742 3724 4990 2944-2947, 2969-2971, 3460 6228-6229 3098-3100 6166-6170 3461-3462 5048-5051 5045-5047 4182-4184 5055-5063 5017 5014-5015 5016 5007-5013 3302 4989-4990 . . 815-816 810 812 . . 829-841 3685 3244 B6oi6 4492 317 318-319,614 1185-1191 6189-6194, 6270-6273 6321 47T5-473° Orsat-Dennis' Gas Analysis Apparatus .. 4715 Orsat-Fischer's „ „ ,, 4721-4722 Orsat-Lunge's „ ,, ,, 4717-1^4719 Orth's Earth Borers . . . . . . . . 5730 Osmometer Tubes . . . . . . . . 784 Ostwald's Burner . . . . . . . . 3513 Capillary Electrometer . . . . 5259 Slide Meter Bridge . . . . . . 5342 Thermostat . . . . . . . . 5272 Outfits, Diagnosis .. .. .. ..511-524 for Carrying Anthrax Specimens ,, Preparing Mosquitoes Oval Specimen Jars . . . . . . . . 3378 Oven Thermometers . . . . . . 4172-4173 Ovens, Drying, Brazed, for high temperatures 2462, 2474 ,, Hot Air . . . . 2454-2461 „ Hot Water . . . . 2463-2488 ,, Steam.. .. .. .. 2477 „ Vacuum . . . . 5229-5232 Paraffin embedding . . . . . . 394 Oxygen Blowpipe, Fletcher's . . . . . . 2018 Cylinders . . . . . . . . 3067 Gas . . . . . . . . . . 3068 Retorts . . . . . . 3799-3801 Tubes, Glass . . . . . . 4310 Oxy-hydrogen Gas Generator . . . . . . 4682 Ozone Apparatus, Brame's .. .. .. 4317 14 -CROSS STREET • HATTON GARDEN, E- C BAIRD &TATLOCK (LOM)ON)LTD. INDEX. Ozone Tube Ozotometcr Pads, Sectional Paper Page's Gas Regulator Pagoscope Pails, Laboratory Paine's Laboratory Filter ,, Microscope Lamp Pake's Enumerating Discs ,, Pressure Filter ,, Water Sample Case Palettes Palladium Tubes Pans, Dyers' Gold-Washing Iron, Enamelled Mixing Scale, Horn Paper Absorption Mats Asbestos Balance for Counting Squares Drying, Botanical Filter Glazed Glazed, for Klinostats Heat Test Mounting, Botanical Parchment Scales, Leunig's Sectional Squares, Thresh's Trays Weighing Paraboloid Condenser, Zeiss' Paraffin Block Cases Embedding Baths Blocks Oil Furnaces Parchment Paper Parker's Hide Powder. . Parnell's CO, Apparatus Parting Flask Stands Flasks Set, Silica Pasteur's Flasks Test Tubes .. Pastilles, Charcoal Paterson's Rotator Pathological Specimens Paul's Apparatus Payne-Gallwey Computing Dial Peake's Control Board Peander Set of Meteorological Instruments Pedestal Spring Balances Pediment Barometers Pencils, Charcoal for Writing on Glass Pens for Barographs Pensky-Marten's Flash Point Apparatus Pentane Standard Lamps Peptone Broth Media No. 4315 4560 2636-2638 . . 427 6138 726 692 464 559 710 736 4205 4685-4686 1968 6230-6237 6264 1969 1877 4206 3550 1767 557 4420 2619-2621, 2640-2681 6326 45°i 3631 4421 .. 716-717 2622-2639 5083 2676 4383 H43 1483 •- 385-399 404 3460 .. 716-717 5227 2165 6327-6328 2732-2734 A24O6 536, 548, 550, 551 535 2044 4834 578 3798 3212 5508-5511 6134 1783-1784 6061-6063 2046 2450, 2451 .. 01937 5004 4826-4830 54° Pepy's Gas-holders .. .. .. 3034-3041,3043 Perforated Brass Sheet . . . . . . 5719 Periodic Collecting Cabinet . . . . 5988-5989 Perkin & Kipping's Models . . . . 3562-3564 Perkin's Sulphuretted Hydrogen Apparatus . . 4041 Petri Dishes, various .. .. .. 636-641,651 6166-6170 3457-3458 1461 : ' • • • 972-975 4680 47IO-A47IO 4584 1982 374° 3743 3742 3741 3737- 3739. 4811 4806-4813 4820-4859 4845-4846 4823-4824, 4841-4843 4844 4838-4840 5222-5224 1071-1075 1142 45°4 1660-1676 4118, 4119 Petroleum Burners „ Heating Stoves Oil Stoves Testing Apparatus . . Petrological Microscopes, Leitz's Pettenkotfer's Absorption Tube . . Pettersen's & Palmquist's Apparatus Pfltiger's Blood-Gas Apparatus . . Phelp's Registration Apparatus. . Phillip's Beakers Phosphorus Spoons Photographic Dishes Enamelled „ ,, Stoneware „ Drainer . . „ Film Weight Plate Washer Photometer Bars „ Benches Photometers, Accessories for ,, Box, •Lummer-Brodhun Flicker . . ,, Hand, Dibdin's ,, Simple Photometric Apparatus, Jackson's (Cement) Photo-micrographic Apparatus, Leitz's . . „ Zeiss' . . Photo Synthometer, Ganong's Physical Apparatus (see separate list). ,, Balances „ Thermometers .. ..4115 Physiological Apparatus (see separate list). „ Diagrams . . . . 6000-6003 Physiology of Plants Apparatus . . 4493 4584 Picnometer . . . . . . . . . . 3858 Picro-Saccharometer, Johnston's . . . . 769 Pigmentation Meter . . . . . . . . 4227 Pins, Entomological .. .. .. .. 66 1 Pipeclay Triangles . . . . . . 4283-4285 Pipes, Channel, Fireclay .. .. .. 175-207 „ Silica . . . . . . . . . . 2425 Pipette Electrode .. .. .. .. 5315 „ Rest, Porcelain . . . . . . 3886 ,, Stand . . . . . . . . 3891 Pipettes .. .. .. .. 3177-3187 Automatic . . . . . . 3185-3187 Cobbett's . . . . . . . . 3184 ICttling's . . . . . . . . 4674 for Milk . . . . . . . . 4928 ,, Wassermann's Test . . . . 417-418 Graduated .. .. .. .. 3181 for Sera . . . . . . 3183 in case, Klein's . . . . 798 „ Strong & Seligman's 799 Nabarro's . . . . 800 with Opal Backs . . . . 795-797 „ Zero at point. . .. 3182 Griinbraum's . . . . . . 870 Hempel's . . . . . . 4663-4679 Lunge & Rey's . . . . . . 3868 Opsonic .. .. .. 318.319,614 Plain . . . . . . . . 3745 Rothe's . . . . 4709 2nd quality . . . . . . 3180 standard .. .. .. 3177-3178 with Mark, various forms .. .. 3«79 Pistons, India-rubber for Syringes . . . . 476 Pith.. .. . . .. .. .. 1454 Plane Table . . . . . . . . . . 6384 Plant Life, Diagrams of .. 6009-6013 „ Physiology Apparatus . . . . 4493-4584 Plaster, Adhesive, Mead's . . . . . . 758 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &. TATLOCK (LONDON) LTD. INDEX. Plate Drainers Washers Plates, Air Pump Celluloid, for weights Copper „ for Drying Slides Eternod's Glass, black and white . . „ for Desiccators „ for Levelling Stand „ with Cavities Porcelain for Desiccators ,, Micro slides ,, Sputum „ Weights .. Porous Silica Platinum Anode „ Apparatus, various . . „ Basins Boats Cathode „ Crucibles ,, Dishes Electrodes No. 3742 3744 3712-3713 1880 2306 579 1437 630 2438 494 1442 2440 587 588 1879 4208 2419-2420 5-S7 2342-2382 2348 62360-2362 5258 2342 2350-2353 2368-2382,5256 for Hoffmann's Apparatus . . 5935 Filter Cones . . . . • • 2349 Gauze . . . . . . • • 2365 Iridium Needles . . . . I5X3 „ Needles for Syringes . . 478 Loops for making Rods . . . . I5°6 Muffles . . . . . . . - 2363 Needle-holders .. .. 1514-1515 Resistance Couples . . . . 5588-5602 Sheet, perforated . . . . - - 2364 Spade .. .. .. .. 1522 ,, Spatulas ,, Spoons ,, „ in Glass Handles „ Triangles „ Wire Holder Pliers, Square Nose „ Straight Nose . . ,, Various Plimmer's Nitrogen Apparatus . . Plimpton's Gas Holders Plug Key Switches Plugs, Brass, for Sinks „ for Cylinder Valve Socket Plumbago Crucibles 2357-2359 . . 2354-2355, 2360 730 2367 2053 2589 2590 6317-6320 3647 3°3°-3°32 • • 5362-5365, A5368 . . 167-169 3080 6177 Plummet, Thermometer, for Sp. Gr. Balances . . 1762 Pneumatic Troughs, Glass 718, 1957, 3749' 3752> 3753 „ „ Stoneware . . . . 3747-3748 Tin .. .. .. 3746 Pocket Balances .. .. .. 1768-1769 Clinometers . . . . . . 6423, 6424, 6427 Compass . . . . . . 6428 Folding Nets . . . . . . . . 662-663 Microscope Cabinet . . . . . . 657 Reflecting Levels, Locke's . . 6425-6426 Sextant . . . . . . . . 6422 Spatulas, Horn . . . . . . 3825 „ Steel . . . . . . 3826 Spectroscopes . . . . . . 5740-5741 Poker, Iron . . . . . . . . . . 6322 Polarisation Apparatus for Cane Sugar . . . . 5907 Polariscope Cases . . . . . . . . 5830 ,, Lamps . . . . . . 5855-5864 „ Tubes . . . . . . 5865-5871 Polariscopes and Accessories, Schmidt and Haensch's 5808-5887 Laurent's . . . . 5888-5906 Polarisers, Bausch and Lomb's . . 1346-1347 Polarising Apparatus, Education set of . . „ Leitz's . . . . 1046-1047 „ Swift's .. .. 1408-1411 Polenske's Apparatus . . . . . . 4937 Polishing Machines . . - . 3678, 3&79, 3681 Pollard's Regulator .. •• 3873 Porcelain Acid Dishes 2439, 3053 Ash Trays . . . . . . 3554 Balloon Filters 2618 „ Basins, various shapes .. 1938-1948 „ Beakers .. .. .. iySo Boats ,, Bunsen Burners 3498-3499 „ Capsules, Meissen . . . . 2325 „ Royal Berlin . . 2326 ,, Covers for Baths . . . . . . 2537 Crucibles, Gooch's . . 2332, 2682 „ „ Meissen . . . . 2328 „ Rose's . . . . 2329-2331 „ „ Royal Berlin . . . . 2327 „ Draining Tube Rack . . . . . . 3924 Filter Cones .. „ Discs . . „ Drainers . . . . 2712 „ Rings.. .. .. jDi.(-20i5 Flasks . . . . 2743 Funnels, Dr. Buchner's „ Dr. Hirsch's . . 2804 Mortars and Pestles . . . . 357°-3572 Mercury Troughs . . 3757-3759 Pipette Rest „ Plates for Desiccators ,, Micro slides ,, ,, Sputum „ ,, Weights . . . . . . ,, Pots „ Rings for Baths . . . . ,, Steam Jacket for Beckman's Apparatus Slipper, Cassall's . . . . Spatulas . . „ Staining Troughs . . . . . ,, Supports for Charcoal Pastilles Tiles . . . . . . Trays ,, Troughs for Paraffin Embedding „ Tubes . . . . . - „ Watch Glasses . . Poroscope . . . . . . . . Porous Blocks „ „ Sporulating Filters . . Pots Saucers . . Soup Plates . . Tiles . . . . Trays . . Portable Batteries Pyrometers . . . . 5394-34°3 Post Boxes for Microscope Slides Potash Bulbs, Anderson's Delisle's Dittmar's Gomberg's Hill's . . Liebig's Mohr's . . new form Ure's . . Potato Borers Media 2440 5»7 588 1879 599 2536 2/57 4917 3834-3S35 .. 583-584 2045 4201-4204 587 4°3 4306-4307 •1351 454° 5696 . . 649-050 2617, 2618 5695 4209 4208 4207 5693-5694 5377 5464-5473. 55°2 1458-1460 3761 .. 3763 3762 3/68 3765, 3766, 3769 3767- 377° 3771 502 54° CROSS STREET • HATTOTST GARDE1ST, E-C BAIRD &.TATLOCK (LONDON) LTD. INDEX. 1765-1766, 1774-1775, 6406-6415 Potato Tubes, Roux's Potometer, Ganong's . . ,, Pethybridge's Pots, Aluminium „ Glass, Shallow . . ,, Porcelain „ Porous . . ,, Stoneware Pounders Praussnitz's Weighing Cups Prescription Scales Pressers, Cork Presses, Botanical Filter for Making Coal Pastilles Laboratory, Small Meat Sodium Tincture Pressure Bottles Filters, Berkefeld „ Doulton's ,, Houston's „ Lazarus-Barlow's „ Pake's Gauge, Gas Recorders Regulator, Beard's Prisms, Erecting, Leitz's ,, for Spectroscopic work . . „ Hollow Prismatic Compasses Projection Apparatus, Leitz's ,, „ Zeiss' „ Nernst Lamp, Zeiss' Prospecting Picks Prospector's Furnaces, Portable ,, Rule and Scale of Hardness. . Pulfrich Refractometers Pulse Glass Pump Models Pumps, Air . . . . . . 37°7, 37°8 Compressing Double Barrel Geryk . . . . 37I7-37I9. Mercury . . 3577-3579: Rotary Tate's Blood Gases, Hill's Exhaust Filter, Arzberger & Zulkowsky's Brass Bunsen's Fischer's Glass . . . . 3686-3688 Korting's New form Starkey's Mercury, Adeney's Buckmaster & Gardner's Friedrich's Sprengel Vacuum Waller's Water Blast Punch, Leaf Punches Puncturing Apparatus, Laker's Purinometer, Dr. Walker-Halls Pyknometer, Bousfield's „ Hartley & Barrett's No. • 526-527 4511 5682 45°9 646 599 5695 5662 6243 2123-2124 1785-1787 2318-2319 4417-4419 2685-2702 A5&46 3754 • 572-575 3840-3841 3755-3756 2140-2143 . 696-703 . 680-681 708-709 711 710 3083-3084 4863-4865 3085-3087 1051 437° 2162 6438-6439 1077-1088 1156-1157 1148 6275 6222-6226 6161 4980-4982 3774 3776-3790 3712-3716 3720 3714-3716 3721, 3722 3585-3587 3728-3731 37°5-37°6 790 707 3686 3689-3694 3687 3698-3699 3695-3700 3692-3693 3700 3694 5087-5089 . • ^3588 3588 3589-3591 37I7-373I 792 3702-3703 4494 6323-6325 868 761 5297 5296 Pyknometer Tubes, Silica . . . . . . 2406 Pyrological Cabinet, Ross's . . . . ' Pyrometer Outlit , 5384-5418, 55>*-55'5. 5584-558? ,, Tubes, Silica . . . . . . 2409 Pyrometers, Accessories for .. 5419-5453.5486-5489 for Flues, etc. . . . . . . 5495 ,, Ovens, etc. . . . . 5496-5501 Platinum Resistance . . 5572-5602 Portable . . . . 5394-5403. 5464-5473. 55°* Radiation, Fery . . 56 13-5605 Recording 5404-5411, 5474-5485, 55°4-55°7 „ Calendar's . . 5574-5583 Spiral, Fery . . . . . . 5606 Wall Type . . 5384-5393- 5454'5463. 55°3 Water, Siemen's . . . . 5383, 35383 Quadrupod Stands . . . . . . 4290-4291 Quartz Apparatus, Transparent . . 2384-.\24o6 ,, Mortar ' . . . . . . . . 6298 „ Spectrograph . . . . . . . . 5789 Rabe's Water Turbines . . . . . . 4336 Rack, Test Tube, for Wasserman's Test . . . . 414-110 ,, Turning out . . . . . . . . 6367 Radial Burners, Fletcher's . . . . 3525, 3529-3531 Radiation Pyrometer, Fery . . . . _• 5603-5605 Rain Gauges, British Association Pattern 6106-6107 Glaisher's . . . . 6102-6103 Howard's .. .. 6100-6101 Self -Recording .. .. 6115-6116 Symond's . . . . 6104-6105 Symond's Snowdon . . 6108-6109 Wilson's .. .. 6110-6114 Ram, Model of . . . . 379O Ramsay's Divider .. .. .. .. 3118 ,, Furnace . . . . . . 2815-2816 Range Finder . . . . . . . . 6440 Ranvier's Microscope Slides .. .. .. 144° Raplin Ice-Making Machine . . . . . . 3704 Razor Hones . . . . . . '597 Strops.. .. 1599-1600 Razors, Microtome . . . . . . . . 1598 Reading Lens . . . . . . . . 567 „ Table Telescopes . . . . 3056-3066 Reagent Bottles . . . . . . 2054-2077 „ Labels, in book form . . . . 3436-3437 „ „ in boxes . . . . . . 3439 Reagents .. .. .. .. pages 1196-1246 Receivers, Bredt's . . . . . . 2300, 2301 for Distillates . . . . . . 2297 „ ,, Lothar Meyer's .. 2299 „ Retorts .. .. 3806-3811 ,, with ground in tubes . . . . 3815 " Record " Hypodermic Syringes . . 479 Recorders, Bi-meter CO2 . . . . . . 4771 CO, .. .. .. 4848-4857 Combustion, Sijnmance-Abady . . 4847 Heat. Watkins . . . . . . 5494 Pressure . . . . . . 4863-4865 Recording Drums . . . . . . 4495-4497 Levers . . . . . . 4498, .-^4498, 4502 Pyrometers ,, Callendar's Transpirometer Rectangular Specimen Jars Reduction Tubes Redwood's Ebonite Indicator . . 5404-5411, 5474-5485 5574-5583 3422-3424 2201-2202 5062 1273 BAIRD ^TXTLOCK (LONDON) LTD. INDEX. 4944-4966, Redwood's Gun Metal Weight . . Vapour and Gas Detectors Yiscometers „ for Oil Fuel Water Finder Ree's Microscope Cabinet Refills for Gas Lighters Reflecting Condensers, Leitz's . . ,, < ialvanameters „ Levels, Locke's Reflux Condenser Refractometer Scale, Leach & Lythgoe's Refractometers, Thornoe's „ Zeiss' Refrigerator Thermometers Registration Apparatus, Phelps' Regnault's Hygrometers „ Sp. Gr. Bottles Regulators, Beard's „ Gas Pollard's .. Reichel's Filters Reichert-Meissl Apparatus Reichert-Muencke, Gas Regulator Reichert-Wollny Apparatus .Reichert's Dissecting Microscopes Eyepieces, Compensating ,, Huyghenian ,, Projection ,, ,, Revolving ,, ,, Spectroscopic „ Gas Regulator ,, Mechanical Stage „ .Microscopes ,, Microtomes „ Nosepieces ,, Objectives, Achromatic ,, „ Apochromatic ,, ,, for Photo-Micrography, &c „ Spectroscopes Reinhardt's Desiccator Reinke's Germinating Apparatus Reiset's Apparatus Rennet Glass Reservoirs, Mercury Resistance Boxes Cells . . . . . . 5304. Coil ,, Frames „ Lamp „ Glass Basins „ „ Beakers „ „ Bottles „ ,, Flasks 2716, 2717, 2727, 2732 „ ,, Retorts „ Pyrometers Respiration Apparatus (Plants) Respirator Respirometers Rests, Scalpel Retort Clamps Rings .. .. .. 3895, Stands Stands with Twin Rods Retorts. Copper Fireclay Iron, for Mercury Distillation . . Glass, Bohemian ,, Jena . . ,, Resistance with Receiver . No. 5061 5055-5063 5009-5013 5007 5°55 657 3550 1052-1063 5382 6425-6426 4936 4992 4967 4968-4987 4176-4177 4584 6141-6142 3857 3°85-3°87 • 427-437 3873 . 690-691 4937 429 4935 1249-1251 1255 1252 1256 1259-1260 . 1258 428 1244-1245 1208-1263 1261-1263 1253 1254 1257 5740-574i 2433 5700 4689 4920 3592 5318-5325 53IO-5312 5379 5369-5370 5346 1955 1971, 1975 2070 , 2739-2741 3797 5572-5602 4561-4570 3°93 4507-4508 1519, 1520 2216 3897, 3906 3892-3905 5289 3799, 3800 3804-3805 3802, 3803 3791-3793 3794-3796 3797 3806 Retorts, Sheet Iron, for Oxygen Silica Revenue Still, Indian pattern . . ,, ,, Thorpe's Reverberatory Gas Furnaces Reversible Aspirators Reynolds' Drying Ovens Rhenish Filter Paper . . Rheostats, Dial Richardson's Gas Washing Bottles Richmond's Slide Scale Rideal- Walker's Stand Rider Weights for Sp. Gr. Balances Riders, Balance Ring Burners Rings, Aluminium Copper, in sets Cork .. Filter, Porcelain Gas Glass India-rubber, for Filter Flasks Nickel, with boss Porcelain for Baths Retort Ripper's Weighing Burette Roasting Dishes Robertson's Canute ,, Xitro-glycerine Apparatus Robinson's Hot Air Motors ,, Anemometers Rocking Apparatus, Dr. Bour's . . „ Microtomes, Cambridge Rod Moulds Rods, Demonstration for making Platinum Loops Glass Silica Specific Gravity Stirring Rogers' Sphygmomanometer Rohrbeck's CO2 Apparatus Root Manometer ,, Pressure Apparatus Root's Blowers Roscoe & Lunt's Flasks Rosenhain's Calorimeter Rose's CO2 Apparatus ,, Crucible, Porcelain ,, Fusel Oil Apparatus Roses for Bunsen Burners Ross's Mortar ,, Pyrological Cabinet Rotary Haemoglobinometer, Hall's ,, Microtome, Minot's ,, Pressure and Vacuum Pumps Rotator, Paterson's Roth's Melting Point Apparatus Rothe's Pipette Round Files Roux Gas Regulators Roux's Culture Flasks. . Roux's Hypodermic Syringes „ Potato Tubes Royal Berlin Porcelain Capsules ,, ,, ,, Crucibles Rubber Stamps Tape Ruhemann's Urinometer Rules, Boxwood Calculating, Barnard's . . No. 3801 2395 2267 2258-2266 2900-2903 3733-3736 2469-2471 2648-2681 5328-5339 4379 4908 728^728 1763 1868 • • 457-458 2510 3949 2614-2615 3491, 3492 1450 2721 2^66 2536 3895. 3897. 39°6 3134 6329 484 3615-3623 6054-6055 597 1568, 1588 6316 3224 1506 3104 2400, 2408 3871 3951 814 2169-2170 4514 . 4544-4S48 2033-2037 553 5637-5043 2173 2329-2331 3017-3019 3479-3480 .. 66152 . . B6i55 809 1644-1649 3728-3731 4834 4515 47°9 2576-2577, 6208, 6209 •• 433-434 .. .. 473-478 .. 526-527 2326 .. 3334 3218-3227, 3250 CROSS STREET • HATTQTsf GARDEN, E-C 1274 I BAIRD &TATLOCK (LONDON) LTD. INDEX Rules, Calculating, Faber's „ ,, Fuller's „ Steel Rumpler's Filtering Cups Rupert's Drops Ruprecht's Balance Saccharometers „ Balling's „ Brix's „ liinhorn's „ Lohnstein'-s Sach's Double Bell Jars Safety Funnels Sahli's Haemometer Salamander Crucibles . . ,, Crucible Jackets Salinometers, Brass Glass Salter's Cement Testing Machine Salvarsan Apparatus Sample Balances Boxes, Tin „ Wood Cases for water „ „ Army Pattern 3208-3211, 3213, 3214 3216-3217 . . 3228-3232, 3237 2681 3816 1680-1682 33°3-33°6, 3336-3337. 3343-3352 3360 3361 780 774 1999 2798-2802 ASo? 6173-6176 „ ,, Dr. Houston's „ ,, Dr. Pake's Tubes Samplers, Clover Com Steel Water Sampling Shovels Troughs Tubes, Gas Sand Baths . . „ Blasted Label Bottles ,, Time Glasses Sankey's Machine for Testing Metals " Sarco " Calonmeter Sarnstrom's Flask Sartorius Balances „ Specific Gravity Balances ,, . ,, Weights Saucers, Porous ,, Stoneware Sausage Skin Dialysers Savage's Cooling Apparatus Saw, Charcoal . . . . ... „ Hand and Power Scale Pans, Horn Scales, Boxwood, Horizontal Vertical Cardboard, Horizontal „ Vertical Dispensing .. .. I774'I775: for Measuring Buttons for Weighing Samples Haemoglobinometer, Tallquist's . . Hand Mirror Glass of Hardness and Density Rule . . Opal „ . . Plain „ . . Prescription, Becker's . . ,, various .. 1774-1775 Refractometer, Leach & Lythgoe's Standard B3352, 03352 3359 5190-5196 487 1788 6331 6330 •• 733-735 732 731 73° 2087-2092 5689-5690 5691 6334 5082 6333 6332 3045. 3°5°. 3°5i 2071-2072 2540 S6?? 5646 4699 1722-1732 1759-1760 1801-1803 4209 585 713 658 2047 3680 1877 3218-3227 3239 3233-3236 3240-3242 1785-1787 6250 1788 801 1774 3243 6161 6244 3245 1765-1766 1785-1787 4992 3206-3207 Scalpel Rests.. .. .. .. 1519-1520 ,, Trays, Glass . . . . . . . . 3408 Scalpels, Various . . . . 152 1 Schanze's Microtomes . . . . . . 160; Scheibler's Basin, Nickel . . . . . . 1951 ,, < ulcimeter . . . . . . 5210 „ Desiccators .. .. 242(1 Schirf s Gas Absorption Apparatus . . . . 4380 „ Nitrometer . . . . . . . . 3597 Schimmel's Oil Flask . . . . . . I Schimmelbusch's Autoclaves . . . . . . 342 ,, Steam Sterilisers . . . . 336-337 Schleicher & Schull's Extraction Thimbles .. 2556 Filter Paper . . 2648-2681 Schmidt & Haensch Spectroscopes 5735-5744. 579°-57W Schonjahn's Seed Germinating Apparatus . . 5686 Schopper's Apparatus . . . . . . . . 5244 Schrodter CO, Apparatus .. .. 2166,2167 Schultze Elutriating Apparatus. . .. .. 5705 Schulze Moist Cliambers . . . . . . '452 Schumann's Cement Testing Apparatus . . 5218-5219 Schuster's Alkalimeters .. .. 2107-2108 „ Drop Bottles .. .. ..611-012 Schwarz's Apparatus . . . . . . . . 3598 Science Diagrams . . . . . . 6004-6008 Lanterns . . . . . . 3844-3847 Scientific Books . . pages 1173-1186 Scissors, Various . . . . 1527-1530, 2599, 3839 Scoops, Aluminium . . 3838 Amalgam . . . . . . . . 6335 Copper . . . . 6337 for Filling Crucibles . . . . . . 6336 3836. Horn Vulcanite Scorifier Tongs Scorifiers, Clay Scotometer, Haycraft's Scrapers ,, Horn Screen, Laboratory, Sturtevant. . ,, Thermometer, Stephenson's „ Lamp „ Light ,, Optical Projection Screwdrivers Screw Micrometer Eyepiece, Leitz's Sealer for Clamping Lead Seals . . Seals, Lead Sebatier's Ink for Writing on Glass Seck's Mills Section Lifters Sectional Pads „ Paper Sedgwick-Tucker Aerobioscope . . Sediment Vessel, Wynter Blyth's Seed Collections „ Germinating Apparatus .. „ Testing Apparatus, Stainer's „ „ „ Weinzierl's „ „ Incubator „ Seger Cones Selenite and Mica Films, Leitz's Seli-Recording Barometers „ Hygrometer „ Rain Gauge „ Thermometer Selvyt Cloths Senier's Apparatus for Nitric Oxide Separators ,, Broegger Harada's for Minerals 6339. 6338 6376 6343 875 6340-6341,6344-6345 3837 6273 6150- 3553 4505-4506 1185-1191 2597 1027 6347 6346 3364 . . 3672, 3673, 3676 1488-1491 2636-2638 2622-2639- 525 5°79 5732 5686-5700 57°' 5677 5678-5679 5492 1048 BI937-DI937 6119. 6110-6116 6120 4335 5962 2789-2793 5710 5068- 1275 BAIRD &TMXOCK (LONDON) LTD. INDEX. No. Separators, Nobbe's . . . . 567° „ Ore, Electro-Magnetic .. .. 6321 Thoulet's .. .. .. •• 5711 NVcinzierl's.. .. .. .. 5680 Serpent Tubes . . . . . . 531 Serum Bottle Caps, India-rubber . . 5O1 Bottles .. .. .. 2112-2115 .. Flasks.. .. 2114-2115 Inspissators, various . . . . • • 377-382 „ Pipettes .. .. •• 3183 Syringes . . . . . . 482 Sets, Blowpipe . . . . . . A6l55-6i6o „ Dissecting . . . . I532'I544 Setting Boards . . . . . . • • 667 „ Houses . . . . . . • - 668 Sextant, Pocket . . . . • • 6422 Shaking Apparatus for Gerber's Tubes . . 489 1 „ Leather Testing . . 5228, 5236-5239 „ Wagner's . . . . 5720-5727 Case to hold Gerber's Tubes . . 4895 Machines . . . . . . 3956-3967 Dunstan & Dymond's . . 3955 Shattock's Glass Jars . . . . . . . . 655 Shears for Cutting Metal . . 2591, 6348-6349 Sheeting, India-rubber . . . . . . 6245 Sheets, Cork . . . . . . . • • . 660 Shelf Clamp, Carmody's . . . . . . 2225 „ Fittings . . . . . . . . 270 Shells, Diffusion . . . . . . 722, 2678 Shelves, Beehive . . . . . . 375°-375i Shives .. 2309, 2312 Shovels for Furnace . . . . . . • . 6342 „ Miner's . . . . . . 6274, A6274 Sampling . . . . . . . . 6332 Show Bottles .. .. 2154-2155 Siau's Constant Temperature Drying Oven . . 2500 Siedentopf Paraboloid Condenser . . 1182-1184 Siemen's Water Pyrometer . . . . 5383-55383 Sieves for Basic Slag . . . . . . . . 5714 ,, Beetroot Seeds . . . . 5665-5666 „ Clover, etc. . . . . . . 5667 „ Cordite Test . . . . . . 3630 „ Soil Testing . . . . 5715-5719 Standard . . . . . . 6354-6356 Tin Rims . . . . . . 6351-6353 Weinzierl's . . . . . . . . 5668 Wood Rims . . . . . . . . 6350 Sike's Hydrometers, Brass . . . . 3338-3342 „ „ Glass . . . . 3271-3272 „ in sets . . 3273-3275 Silica Apparatus, Opaque . . 2407-2426 ,, ,, Transparent . . . . 2384-A2406 „ Combustion Tubes .. .. 3101-3103 Silver Basins . . . . . . . . 1 964 Flask . . . . . . . . . . 2256 Silvered Pins, Entomological . . . . . . 66 1 Simmance Pentane Standard Lamps . . 4826-4828 Simmance & Abady's Boiler Tester . . . . 4725 Calorimeters . . 5607-5609 ,, Recording 5612-5616 Combustion Recorder . . 4847 CO8 Recorders . . 4848-4857 Corrosive Gas Analysers 4858-4859 Gravitometers . . 4860-4862 Laboratory Meters 4774-4800 Orsat's Apparatus 4726-4730 Ventilating Hygrometer . . 4833 Simplex Ore Crushers . . . . . . 6192-6193 Sinks, Laboratory .. .. .. 119,135-174 Six's Max. and Min. Thermometers, 4160-4161, 4165, 6144-6145 Sketching Board . . . . . . 6442-6443 NCI. Skimmer for Crucibles. . 6357-6358 Skins, Chamois . . . . . . 6171 Slide Benches .. .. .. • • 49 Boxes . . 1462-1467 Cabinets .. 1461 Clips . . . . . . . . 595-596 Heaters . . . . 579-582 Jar . . . . . . 607 Meter Bridges . . 534°-5343 ,, ,, Ostwald's . . . . . . 5342 Rocker, Dr. Bour's . . . . . . 597 Rules, Barnard's . . . . . . 3215 Faber's .. .. 3208-3211,3213,3214 ,, Fuller's . . . . • . . 3216-3217 Scale, Richmond's . . . . . . 4908 Stand Trays .. .. .. 1468-1471 Slides, Lantern, British Trees . . . . . . 4403 for Haemodynamometei . . . . . . 813 Microscope .. .. .. 1423-1449 Sliding Microtomes, Cambridge .. I577-'5S5 „ Jung's . . . . 1602-1605 ,, Schanze's . . . . 1607-1609 Objective Changer, Zeiss' .. 1132-1135 Slipper, Porcelain, Cassall's .. .. .. 4917 Slips of Glass, Blue . . . . . . 3881 Sodeau's Gas Analysis Apparatus .. 471^ Sodium Presses .. 3840-3841 ,, Spoon . . . . . . . . 3879 Soil Testing Apparatus, Benningsen's . . . . 5708 ,, ,, „ Broegger-Harada's . . 5710 „ ,, „ Knop's . . . . 5709 „ „ ,, Thoulet's .. .. 5711 ,, Washing Apparatus .. .. .. A 5 705 Soldering Bit ,, Burner . . . . . . . . 3843 Solmedia . . . . . . 539 Solution Jars, Glass . . . . . . 3414-3416 Soup Plates, Porous . . . . . . . . 4208 Soxhlet's & Henkel's Apparatus . . . . 4906 Apparatus for Milk Analysis . . 4909-4913 Autoclave . . . . . . . . 5681 Condenser . . . . . . . . 2248 Drying Oven . . . . . . 2502 Fat Extraction Apparatus . . 2548-2554 Filter Tube . . . . . . . . 2713 Kettle for Sterilising Milk . . . . 365 Lactometers . . . . 4931-4932 Soyka's Bottles . . . . . . 724-725 Spade, Platinum . . . . . . I522 Spanners, Adjustable . . . . . . 2603 ,, for Gas Cylinders . . . . . . 3079 Sparking Tubes " Sparsam " Burners . . . . . . . . 3488 Spatulas, Bone German Silver . . . . . . 3824 Glass . . . . . . . . 3829 „ Tongue . . . . . . 3421 Horn . . . . . . 3820-3823, 3877 „ Folding . . . . . . 3825 Nickel . . . . . . 3831-3833 with Spoon End . . . . 3382 Platinum . . . . . . 2357-2359 Porcelain . . . . . . 3834-3835 Steel .. .. .. 3818-3819 Steel, Folding . . . . . . 3826 Vulcanite . . . . . . . . 3827 Spec fie Gravity Apparatus . . . . . . 3865 Balance, Becker's .. i76r ,, „ for Ores, etc. .. .. i764 Mohr's .. .. 1738 CROSS STREET • HATT^ GARDE1ST, E- C BAIRD &TXTLOCK (LONDON) LTD. INDEX. Specific Gravity Balance, Sartorius Westphal's Beads Bottles Chancel's Drilled Stoppers for Gases No. 1759-1760 1757 3800-3864 3307-3308, 3848-3857 3854 3848 3854 Solids and Liquids . . 3866 „ Syrup Regnault's Standard Wanklyn's Warden's with Counterpoise Thermometer Bulbs Cubes Hydrometers 3855 3857 3850 3852 3851 3849 3853, 3856 3867 387o 3263-3264, 3315-3325 in sets 3266-3270, 3310-3322 Pipette, Lunge & Rey's . . 3868 Rods . . . . . . . . 3871 Stools . . . . . . 1878 Tubes . . . . . . 3859 „ Nicol's . . . . . . 3872 Specimen Bottles . . 617-619, 2154-2155, 3365-3368 Inverted Stoppers .. 2151-2152 Mushroom Shape . . . . 2153 Stoppered .. .. .. 2111 Cylinders . . . . . . . . 2138 Jar Covers .. .. 3117, 3373-3376, 3425 Jars . . . . . . 3366-3428 Flat Stoppered Ground Flange at Top . . 3372 Oval .. .. . . Rectangular with Cover ,, Vulcanite Strip Specimens, Bacteriological Medical of British Forest Trees ,, Fruits and Seeds . . ,, the Elements „ Wood Pathological Surgical Spectrograph, Quartz Ultra Violet Glass Spectrometer, Student's Spectroscope Stands Spectroscopes, Beck-Thorp 3370-3371 3379. 338o 3378 3422-3424 3382 538 576 4402 4404 5990-5991 4413 578 577 5789 5787-5788 5747-5762 4367, 5801 4339, 5763-5765 Browning's, 5733, 5734, 5738^5739, 5770-5773 Hoffmann's . . . . 5794-5799 Hilger's 5745, 5774-5789, 5802-5807 Kirchhoff & Bunsen's Reichert's Schmidt & Haensch, Spectrum Analysis Bottles ,, Tubes Tubes Sphygmomanometer, Rogers' Spills, Cedarwood Spiral Glass, for use with Will's Apparatus ,, Pyrometer, Fery Spirit Blowpipe Bunsen Burner Hydrometer Lamp and Bunsen Burner combined Lamps, Berzelius Brass . . . . . . . . 3459 ,, Dornbush's . . . . . . 3450 Lang's .. .. .. 3447-3448 5766-5769, 5790-5791 5740-5741 5735-5744, 5790-5799 4357 4356 4358-436o 814 2048 3625 5606 2016 3453-3456 3335 3470-3473 3449 Ha Spirit Lamps, Luhme's . . . . 3451-3452 with Brass Wick Holder . . . . ' 3443 „ „ Porcelain Wick Holders ,, ,, Side Tubulure . . . . 3445 Levels, Circular . . . . 495, 496, 3255, 6389 Straight.. .. .. 3254,6385-6387 Spiritine Sponges, Gauze Spoons, Capsule „ Deflagrating . . „ for Sampling Bullion . . Glass ,. Horn „ with Spatula End ,, Ignition, Silica „ Iron Lymph, Volkmann's „ Platinum „ ,, in Glass Handles ,, Sodium * Sporulating Blocks „ Dishes, Glass Sprayer, Formalin Spreader, Film Sprengel Pumps Tubes Spring Balance, Jolly's „ Balances ,, Catches ,, Clips, Various (Forceps). . .. Tapes, Steel Sputum Bottles „ Diagnosis Outfits Squares, Counting „ of Indiarubber Stage, Dissecting, Leitz's „ Mechanical, Leitz's „ Swift's Zeiss' „ Micrometer, Bausch & Lomb's Stainer's Seed Testing Apparatus Staining Boxes, Glass . . ,, Clip for Slides „ Pots, Porcelain Stands, of Teak Troughs, Edington's . . Glass „ ,, Porcelain Stammer's Calorimeter Stamps, Rubber Standard Barometers Burettes Burners, Fletcher's . . Cadmium Cell Candles Cylinders, graduated . . Flasks, graduated Oil for Oleorefractometer Pipettes Scale (Length) Sieves „ for Basic Slag . . Solutions Thermometers Yard Measure Stands, Burette „ Carboy Carnegie's ,, Condenser „ Copper, for Needles for Test Tubes.. 1432 755 3878 3025-3027 6359 3875 3876 3877 2405 3874 756 • • 2354, 2355, 2360 730 3879 . . 649-650 648 741 1517-1518 3589-3591 3869 '773 1777-1784 . . 290-292 1485-1505 3246-3249 • • 521-522 .. 519-524 •• 555-557 6246 1013-1014 1023-1026 1384, 1385, 1388, 1391 1126-1128 1345 5701 2161, 2163-2164 .. 595-596 599 . . 602-610 600 . . 589-596, 598, 620 .. 583-584 5028-5030 5676 1926-1932, 6091-6097 3122-3125 3520-3524 5263-5264 4831,5225 3I69-3I70 3152-3153 4990 3177-3178 3206-3207 6354-6356 57M . . pages 1234-1237 .. 4084-4099,4108 3225 3930-3934 3953 3946 3938-3939 506 497 BAIRD &TXTLOCK (LONDON) LTD. INDEX. 3882- Stands, Eudiometer Filter for Ammonia Cylinder . . ,. Drying Slides .. Kiloart's Models „ Gas Cylinders „ Haldane's Apparatus „ Lenses ,. .Milk Tubes „ Nessler Tubes ,, Parting Flasks „ Resting Instruments „ Rotating Electrodes „ Slides „ Spectroscope Tubes . . ,, Water Decomposing Apparatus Funnel . . . . 3882 Hoffmann's Levelling Pipette Quadruped Retort Rideal-Walker's Spectroscope Staining, Teak . . < Teak, with Two Inkwells, etc. . . Test Tube „ Dr. Houston's ,, for Wassermann's Test Tripod, Glass . . „ Iron Universal, various Ureometer Urine Testing with H Tube Stanger & Blount's Cement Flask Star Burners for Spirit Burner . . „ Support for Bunsen Burners Starkey's Filter Pump ,, Serpent Tubes Starters for'Motors Stead's Gas Analysis Apparatus „ Mercury Gasometer Steam Digesters Drying Oven Funnels Jacketed Pans, Copper Sterilisers, Schimmelbusch's ,, various Steel Cylinders for Oxygen Drawing Scale Needles for Syringes . , (Microscope) Punches Rules Sampler Spring Tapes Spatulas „ Folding Thermometer, Mercury Stencil Brushes „ Ink .. Stencil Plates Stephenson's Thermometer Screen Sterile Culture Media Sterilisers, Electric ,, for Bandages ., Hot Air, various „ Steam ,, „ Schimmelbusch's Sterilising Apparatus for Gelatine No. 3M7 3885, 3887-3890 4759 . 579-582 3558 3088-3091 794 4430 3201, 3203 6327, 6328 1521 2383 .92 4367 3941-3942 3885, 3887-3890 493 3891 4290-4291 3892-3905 728-A728 4367, 5801 . . 602-610 616 3919-3929 5080 .. 414-416 4289 4286-4288, 4292 . 762-763 5262 5215 3456 3482 3694 53i 3988-4000 4713-4714 3°33 333-A335 2477 2814 2290 • 336-337 • 343-353 3067 3238 478, 480 1516 6325 3228-3232, 3237 6334 3246-3249 3818-3819 3826 5493 6365 6366 6360-6364 6150 • • 539, 54° •• 359-363 •• 355-358 •• 367-376 •• 343-353 •• 336-337 449 477, Sterilising Baskets „ Boxes ,, ,, for Bandages . . ,, ,, ,, lodoform Gauze „ „ „ Needles, etc. Stills and Condensers, Copper . . „ Bousfield's ,, Hartley's „ Revenue, Indian Pattern . . ,, Thorpe's Revenue Still Watcher, Mohr's Stirrers, Glass Stirring Apparatus „ „ Dupre's ,, „ Witt's ,, Rods Stoke's Colorimeter „ Tubes Stoneware Acid Jugs . . „ Beehive Shelves ,, Bottles for Mercury . . ,, „ with Stopcock „ Brain Jars . . ,, Dishes for Staining Slides ,, Funnels ,, Jars, Airtight Covers ,, ,, Shut-over Lids ,, Lamp Screens , . ,, Photographic Dishes ,, Pneumatic Troughs . . Pots „ Saucers for Staining Sections „ Stopcocks . . ., Trays „ „ for Holding Bottles Stools, Laboratory ,, Specific Gravity Stopcocks, Brass for Air Pumps Glass Capillary Tubes for Aspirator Bottles „ Burettes . . Greiner & Friedrich's Three-way with Branches ,, Mercury Cup Nickel-plated, for Aspirator Stoneware Vulcanite Stoppers for Kjeldahl's Flasks . . ,, India-rubber Stop Watches Storch's Condenser Store Boxes Stoves, Drying „ Oil ,, Petroleum Strong & Seligman's Clinical Case Strops, Razor Students' Balances ,, Barometers Sturtevant Crusher „ Grinders . . ,, Screen Stutzer's Nitrogen Apparatus . . Suberit Mats . . ,, Rings.. „ Sheets Sublimation Apparatus, Bruhl's No. 438, 439, 442 44°, 443-448 629 . . 626-627 628 2269-2278 5286-5287 5288 2267 2258-2266 2304 5295 4008 4009-4010, 5292-5293 3954 3951 3202 4918-4919 2136 375° 2IOI 2135 3427 586 2803 2125 2126 3553 3737- 3739 3747-3748 5662 585 4°34-4°3| 3052 4277-4279 •• 13^-134 1878 4036-4040 3723 4011-4026 4013-4014 4015 4028-4029 4017-4023 4016, 4020-4025 4024-4026 4019 Bottles . . 4027 4°34-4»35 4030-4033 2736 2307-2308 5019-5020 2245 669 2452^453 3461-3462 3457-3458 799 1599-1600 1660-1676, 1684-1686 1933-1934' 6098-6099 6270 6271-6272 6273 3643 395° 3949 660 3654 CROSS STREET • HATTCnST GARDETST, E-C BAIRD &.TATLOCK (LONDON) LTD. INDEX. Suction Cups " Sudan " Petroleum Lamp Sugar Mill ,, Sample Bottles . . „ Thermometers Sugaring Nets Sulhorst Balance for Weighing Corn Sulphur Determination Apparatus Sulphuretted Hydrogen Apparatus Perkins' Sulphuric Acid Apparatus Sulphurous Acid (Anhydrous SOJ " Sunrise " Petroleum Lamp Sunshine Recorder, Campbell Stoke's Supports, Adjustable, with Bell Jar „ or Table for Retort Stands „ Porcelain, for Charcoal Pastilles „ „ Scalpels Table Surgical Bowls, Glass . . ,, Specimens Surveying and Mining Aneroids Sutherland's Flask Swedish Filter Papers Switches, Key ,, Lever Swift's Camera Lucida ,, Condenser Diagnosis Outfit No. 2677 6169 3666 2110 4185-4186 665 5673 4694-4698, 4749-4757 A4O4O Babo's Coram's Dittmar's Friswell's Kipp's Koninck's 4045-4046 4048 4043 4047 4044 4042 4041 5963 3071-3072 6168 6117 4513 2224, 3907 2045 1520 3935-3937 3409-3411 577 „ Mechanical Stage ,, Microscope Lamps „ Microscopes ,, Microtome ,, Nosepieces ,, Objectives, Achromatic . . ,, ,, Apochromatic ,, Oculars, Compensating . . ,, „ Huyghenian ,, Polarising Apparatus Symond's Rain Gauge ,, Snowdon Rain Gauge Synthometer, Photo, Ganong's Syphon Mercury Gauges Syphons Syringe Needles „ Pistons Washers Syringes, Aseptic Serum Brass, Condensing ,, Exhausting ,, ,, and Condensing Glass Hypodermic, various Injection Table Spectroscopes, Hilger's ,, Supports „ Telescopes, Reading Tables, Blow Pipe „ Drawing, Bernhard's ,, Levelling „ Plane „ or Supports for Retort Stands „ Vaccine 3168 2641-82644 5362-5365, A5368 5366-5368 1405-1407 1404 1392 1384-1385, 1388, 1391 . . 466-468 I373-I4II 1567 1398 1400 1399 1401-1402 1403 1408-1411 6104-6105 6108-6109 4504 2283-2285 4049-4052 477, 478, 480 476 475 482 3710 37°9 37" 4°53 .. 471-479 .. 481-483 5774-5779 3935-3937 3056-3066 2038 1141 . . • 6388 6384 2224, 3907 759 Mo. Taeuber's Gas Drying Apparatus .. .. 3193 Tallquist's Hiemoglobinometer Scale . . . . Sot Tape, Asbestos . . . . . . 3548-3349 „ India-rubber .. .. .. .. 4512 Tapes, Steel, Spring . . . . . . 3246-3249 Taplay's Combustion Gas Analyser . . . . 4731 Taps, Gas . . . . . . . . . . 249-269 „ Water . . . . . . . . . . 208-248 Tar Determination Apparatus . . . . . . 4691 Tate's Air Pumps . . . . . . 37°5-37°6 Teak Stands, for Stains . . . . . . 602-610 „ ,, with two Inkwells, etc. . . . . 616 Teats, India-rubber . . . . . . . . 615 Technical Balances . . . . . . 1678, 1679 Teclu Burners . . . . . . 35°°-35°l Telescopes, Reading . . . . . . 3056-3066 Telescopic Bunsens . . . . . . 3487, .-^3487 Nets .. .. .. .. 664 Temperature Charts . . . . . . . . 4137 „ Indicator for Flues, etc. . . . . 5495 „ „ „ Ovens, etc. . . 5496-5501 ,T Whipple's .. 5572-5573 Tennant's Nitrometers .. .. 3611-3612 Test Glasses, Conical . . . . . . . . 4055 ,, Cylindrical . . . . . . 4054 Mixers, Graduated .. .. 3169-3176 Needles, Gold . . . . . . . . 6368 Tube Baskets] . . . . . . . . 4068 Metal . . 438, 439, 442 Bath .. .. .. .. 2539 Brushes . . . . . . 4069-4071 Caps, India-rubber . . . . . . 498-500 Cleaners . . . . . . . . 4073 Holders, Brass . . . . . . 4082 „ Universal . . . . . . 4083 „ Wood . . . . . . 4081 Racks for Wassermann's Test .. 4i4--4i6 Porcelain .. .. .. 3924 Stands . . . . . . 3919-3929 Copper . . 497 ,, Dr. Houston's . . 5080 Tubes . . . . . . . . . 4056-4067 for Heat Test . . . . . . 3629 Graduated . . . . 4061-4062 Jena . . . . . . ' 4065-4066 nested . . . . • . • . 4064 on Sole . . . . . . . . 4063 Pasteur's . . . . . . . . 535 Silica . . . . . . . . 2396 Testing Cabinets • . . . . . . . . 764-766 Tetanus Dish, Gabritschewsky's 652 Text Books on Tintometer . . . . 4261-4263 Theodolette . . . . . . . . 6437 Theodolite Accessories . . . . 6394-6397 Theodolites . . . . . . . . 6392-6393 „ Students' . . . . . . . . 6391 Thermo-Electric Pyrometers . . . . 5384-5602 Thermograph.. .. .. 4163,6120 „ and Barograph Combined . . . . 4164 Thenno-Hydrometers, Fletcher's . . . . 3326 Thermo Regulators, Novy's . . . . . . 431-432 „ Urinometers, Fletcher's . . 3332 Thermometer Magnifiers . . . . . . 53 '7 Plummet for Sp. G. Balances . . 1762 Screen, Stephenson's . . . . 6150 Tubing, Glass .. .. 3112-3113 Thermometers, Anschutz's . . 4139-4141 Bacon . . . . . . . - 4189 Bath . . . . . . . . 4'9° Beckmau's Boiling Point . . 4148 „ Freezing Point . . 4147 ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 1279 BAIRD &1ATLOCK (LONDON) LTD. INDEX No. 4130, 4197 4100-4107 4191-4194 4178 41 10-4125 Thermometers, Benzole „ Brass Cased Brewers' Brine Pipe Chemical ,, Double Scale . . Long .. .. 4127 Circular Dial .. 4179-4181 "Climax" .. .. 4138 Clinical 4i33-4'35 Dairy 4126, 4914 Demonstration Set 6129-6133 Dimenuon, Pocket . . 4188 English .. .. 4084-4114 for Beckman's Apparatus 2761-2772 ,, Cold Mixtures .. 4111-4113 .. High Temperatures, Nitrogen-filled 4109 Steam Sterilisers . . . . 347 ,, works' use Gas Main Hot Bed . Incubator Malt Kiln Mash Tun Maximum and Minimum Naphtha Oil and Varnish Oven Physical Refrigerator 4171 4170 4174-4175 469, 470, 4128, 4129 4167-4169, 4195-4196 4166 4162, 6143-6146 4131, 4199 4182-4184 4172-4173 4118, 4119 4176-4177 Six's Maximum and Minimum, 4160-4161,4165 Solar Radiation Standard, English Steel, Mercury . . Sugar Terrestrial Radiation Toluol Travelling Set . . Varnish and Oil Veterinary Wall Thermostat Bath for Shaker Tank Thermostats Dreyer's Lowry's Ostwald's Thimbles, Extraction, C. S. & S. Thirlmere Water Motors Thistle Funnels Thoma's Haemacytometer, Leitz's „ „ Reichert's Zeiss' ,, Microtome Knives Thompson's Calorimeter Thomson's Calorimeter Thornoe's Refractometer Thorpe's Revenue Still Thoulet's Separator Threadwell's Nitrogen Apparatus Thresh's Paper Squares Thurston's Oil Testers Tidy's Tubes Tiles, Black and White „ Furnace ,, Porcelain . . . . „ Porous Time Glasses, Sand Tin Bottles . . ,, Boxes for Samples ,, Dishes for Weighing Cream , Filter Cutters 6148, 6151 4084-4098, 4108 5493 4185-4186 6147 4198 4187 4182-4184 4136 4142-4146, 6121-6123 • • A 3956 5273 • • 4547. 5272-5284 532 5285 5272 2556 910 2798-2802 .. 854-857 .. 847-853 . . 843-846 1617, 1632-1635 5631-5636 5628-5629 4967 2258-2266 3644 5083 5045-5047 5085 A&3O 2873-2878 4201-4204 4207 254° 2149 633I 4896 2585-A2585 Tincture Presses Tinned Basins Tintometer Sets, Lovibond's . . Text Books ,, Veley's Titrating Apparatus Toluol Thermometers Tongs, Crucible, Iron ,, with Platinum Points Furnace Gun Metal ,, Mercury „ Nickel Tongue Spatulas, Glass Tool Cabinets Towels Towers, Calcium Chloride Tralle's Alcoholometers Transparent Silica Apparatus . . Transpiration Apparatus Transpirometer, Recording Trap Tubes . . Traps, Laboratory Trays, Ash, Porcelain Brass, for Cordite Cutter Cupel for Holding Bottles „ Microscope Slides „ Sloping Culture Media Tubes Glass, Dissecting „ for Instruments . . „ „ Scalpels Paper Porcelain Porous Silica Stoneware, Gas Vulcanite Triangles, Clowes & Coleman's . . Iron Nickel-Chrome wire . . Pipeclay Platinum Silica Triangular Desiccators Files Tripod for Asbestos Air Baths . . ,, Levelling Stand „ Stands, Classen's „ „ Geometric ,, ,, Glass . . ,, ,, Iron Trocar & Canute, Turnbull's Troughs, Catheter, Glass Clay ,, ,, for Blowpipe Work ,, Ear . . ,, for Holding Cultures . . .. Glass, Rectangular Mercury Pneumatic, Glass „ „ Round „ Stoneware Tin Porcelain, for Paraffin Embedding Sampling . ? Staining, Edington's 3755-3756 4210-4203 4261- j jii } 4264! 4566 4I(, 4265-4266, 4274- | j 7 62383^2383 6369-637 4267-427 427 4271-427 342 2594-259 433 2191-219 3287, 328 2384^240 - • 451°, 4550-455 3649-365 15 355 363 620 4277-427 . . 587, 1468-147 40 340 34° 340 261 5693-369 242 305 72 428 4280-428 . . A428 4283-428 . . 2366-2367, 4283 2401, 2410 1789-179 2578-2579, 6210, 6211 254 49 2547 4293-429 428 . . 4286-4288, 429 48 • • 3396, 3401-3404 2881-2882 2052 3418 537 623 3757-3759, 527O-5271 •• 3749-3752, 37.53 1957 3747-3748 3746 40.5 .. 600 Trowel, Botanical Truck, Laboratory T-Tubes, Brass Glass Porcelain 589-596. 59* .. 583-584 44l6 A 129 4338 CROSS STREET • HATTOTST GARDEN, E-C 1280 BAIRD &TXTLOCK. (LONDON) LTD. INDEX. T Tubes Glass „ Rubber Tube Bottles in Cases ,, Stoppered „ Unstoppered Brushes Cases, Wood Blocks Connections Furnaces, various Holders Rack, Porcelain Tubercle Bacilli Tubes, Absorption. No, 433° 4332 2148 2III, 2117 2086 4072 2090-2092 43II-43M 2866-2885, 2914-2917, 2992-3016 2223, 3918 3924 320 Adjustable 4366 Bunsen's .. .. 3r35-3i36 Pettenkoffer's . . . . 4680 • • 539. 54° 1908, 1912-1914 6070-6072 1924-1925, Agar-Agar Arsenic Barometer „ Bunsen's . . 1924-1925, 6066-6069 Blood Serum . . . . . . . . 540 Buchner's .. .. .. .. 528-529 Bulloch's . . . . . . . . 530 Calcium Chloride, various .. 2177-2190 Carbon . . . . . . 3137-3138 Catheter . . 3397 Combustion, Glass . . . . . . 4309 Hill's . . . . 2188 „ Iron . . . . 43o8-A43o8 ,, Porcelain . . ,, Quartz Condensation Cream Culture Media Diffusion Distillation, with Trap . . Drying, Harcourt's Electrometer Filter, Chamberland's . . ,, Doulton's ,, Kitasato's Filtering, Soxhlet's ,, Stoppered for Estimation of Curd Water ,, Leibig's Condensers . . ',, Vapour Density Apparatus Fractional Distillation ,, ,, Glynsky's „ „ Le Bel-Henninger's 4326 „ „ Young's . . 4323-4325 Gas Absorption, Winkler's . . . . 4688 ,, Correction .. .. .. 4723 ,, Exploding . . . . 3022-3023 ,, Measuring .. .. 3148-3150 „ Sampling . . 3045, 3050, 3051 Gelatine . . . . . . . . 540 Gerber's . . . . . . 4886-4890 Gottlieb's . . . . . . . . 4892 Gutta-percha . . . . . . . . 5211 India-rubber . . . . . . . . 4301 Lymph . . . . . . . . 748 Metal, Collapsible . . . . . . 754 Muter's .. .. .. 3251-3252 Nesslerising . . . . . . 3196-3204 Nitrometer, Crum's . . . . . . 3599 on Stand for Comparing Colour of Water 5084 Osmometer . . . . • . . . . 784 Oxygen .. .. .. .. 4310 Ozone .. .. .. .. 4315 Palladium . . 4685-4686 Polariscope . . . . . . 5865-5871 Potato, Roux's . . . . . . 526-527 3101-3103 4319-4320 4921-A492I • • 539, 54° 2445 3649-3651 2194 5254-5255. 5260-5261 . . 683-684 . . 675-681 682 2713 2714 4929 2229-2230 4362 432I-A432I 4327 Tubes, Reduction .. Sample ,, Serpent ,, Silica, Opaque Sparking Specific Gravity Nicol's Spectrum Sprengel Stake's T Brass T Glass T Rubber Test Tidy's Typhoid Vacuum, for Ultra Violet Work „ Hehner's Ward's Widal's Wright's^ Blood Coagulation Y Form * . . . . 2199-2200 Tub ng, Flexible Metallic Glass Bohemian Combustion Coloured for Sealed Tubes Jena, Combustion ,, Composite Manometer Thermometer India-rubber Silica, Transparent Tundish Turbines, Water, Rabe's Turk's Counting Chamber Turnbull's Trocar & Canute Turning out Rack Turntables Twaddell's Hydrometers, Brass Glass „ ,, Glass, in sets " Twin-Albion " Petroleum Lamp Twine Typhoid Sample Case Tubes, Widal's Tyrer's Arsenic Apparatus u Ubbelohde's Melting Point Apparatus Ultra Violet Glass Spectrographs Ultzmann's Uro-Saccharimeter . . Universal Bridge, Kohlrausch's Clover Sieves Holders „ for Thermostats Mixing Machines Projection Apparatus, Leitz's Respirators Stands, various Uralite Urea Apparatus, Dupre's ,, ,, Gerrard's Ure's Eudiometer „ Potash Bulbs Ureometer Stands Ureometers, Doremus' Urine Estimation, Allen's Apparatus ,, Glasses „ Test Cabinets 2201-2202 2087-2092 53' 1407 4369 3859 3872 4339. 4356-4360 3869 4918-4919 4338 433° 433* 4056-4067 5085 •• 533-534 4368 5021, 5022 1447 •• 533-534 786 433'- 4V17 4302-4305 3105, 3107 3108-3109 3116 3110 3111 3"2. 3"3 4297-4300 2397-2399 6261 4336 486 . 6367 M57-AI457 3260 3256-3286 3265, 3279-3282 6170 6377 518 • • 533-534 1906 2775-2778 5787-5788 •• 777-779 5344-5345 5667 4083 5283 3055-3657 1077-1088 3093 3940-3946 3547 767 768 3'44 3771 770-773 783 775-776 764-766 iCHEMICAL, AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. BAIRD &TATLOCK. (LONDON) LTD. INDEX. Vrine Test Stands Urinometers Ruhemann's • ',', Vogel's . . Uro-Saccharimeter, Ultzmann's U Tubes, various forms No. . . 762-763 3329-3334 3334 :• 333° . . 777-779 2177-2186 Vaccine Bulbs or Ampoules Expeller, India-rubber Shaking Machines . . • • • • 9°5-9°7 „ Table 759 Vaccines, Baths for Sterilising . . • • • • 4°°-4o1 Vacuum Distillation Apparatus 2291-2295 „ Drying Ovens .. . • 5229-5232 Gauges, Bourdon's . . • • 3701 McLeod's .. .. •• 3580 Pumps, "Geryk" .. •• 37*7-3724 „ Rotary .. .. 3728-373* „ Stopcock for Air Pumps . . 3723 Tubes for Ultra Violet Work . . • . 43°8 „ Hehner's .. 5021-5022 Vessels, Dewar's . . • • 434°'4344 Vanning Shovels .. .. 6274-^6274 Vaporimeter, Archbutt's .. •• 5°i8 Vapour Density Apparatus, Hoffmann's . . 4363'43D4 „ „ Hoffmann's Guy Lussac 4365 „ „ Victor Meyer's . . 4361 „ Bulbs, Duma's . . . - 4346 Detector . • • • • 5°°3 Varnish Thermometers 4182-4184 Veith's Lactometer . . . 493° Veley's Tintometer . . . . . • • 4264 Ventilating Hygrometer . . . . . 4833 Vertical Camera, Zeiss' . .. 1175-1181 Illuminator, Zeiss' . .. .. H39 Vessels, Containing, for Sterilisers . . 338-34°' 35°-35i Glass, Douche .. .. .'. .. 34J7 „ for holding Lymph . . . . 750-753 „ with Rod and Cap, Wynter Blyth's . . 5079 Veterinary Thermometers .. .. .. 413° Vials, Bologna .. .. .. •• 38l7 Vicat's Needles .. .. .. 5188-5189 Vices . . . . 2604-2613, 6378-6380 Victor Meyer's Crucible Drying Bath . . . . 2538 „ „ Vapour Density Apparatus 4361 Viscometer, Clinical . . . . . . . . 871-874 ,. Coleman-Archbutt's . . . . 5017 Engler's .. .. .. 5014-5015 „ Kunkler's . . . . . . 5016 Redwood's .. ... 5009-5013 „ „ for Oil Fuel . . . . 5°°7 Viscosity Apparatus . . . . . . . . 4345 „ „ for Glue . . . . . . 5023 Vogel's Diaphanoscope . . . . . . 5663 „ Urinometers . . . . . . . . 333° Volhard's Nitrogen Bulbs . . . . . . 3595 Volkmann's Lymph Spoons . . . . . . 756 Voltmeter and Ammeter Combined . . 5380-5381 Voltmeters . . . . . . 5350, 5357-5361 Volumetric Analysis of Gases . . . . 5909-5969 Vulcanite Gratings for Sinks . . . . . . 145 „ Scoops . . . . . . . . 6338 „ Spatulas . . . . . . . . 3827 „ Stopcocks . . . . . . 4°3°-4°33 Trays .. .. .. .. 727 w Wagner's Shaking Apparatus . . . . 572°-5727 Walker & Lumsden's Boiling Point Apparatus . . 2781 Walker-Hall's Purinometer Wall Thermometers . . „ Type Pyrometers Waller's Apparatus Walpole's Colorimeter „ Gas Drying Apparatus Wand Telescopic Nets. . Wanklyn's Specific Gravity Bottles Ward's Tubes Warden's Specific Gravity Bottles Warm Stage for Microscope Wash bottles Washers for Autoclaves „ ,, Hypodermic Syringes Washing Flasks „ Pans Wassermann's Test, Apparatus for Watch Glasses Flat Bottom Green Glass Paired Porcelain Solid .. Tared with' handles Watches, Stop ' . . Water Analysis Apparatus, Bischof's ,, Apparatus, Bunsen's „ „ for Testing Hardness . . „ „ Hoffmann's . . „ Baths, Dr. Houston's Pattern Enamelled Iron for Fat Extraction Apparatus Nickel .. Mashing various Blast Pumps Distillation Apparatus Heaters, Fletcher's Motors, Thirlmere Pyrometers, Siemen's . . Sample Bottles Cases .. ,, ,, Army Pattern ,, ,, Dr. Houston's „ „ Dr. Pake's Sampler Taps Turbines, Rabe's Watkin's Heat Recorders Switch Watson's Microscopes, B. & T. Models . . Wave-Length Spectroscope Weatherhead Combined Mortar and Pulveriser Wedgwood Mortars and Pestles Weed Seeds, Collections Weighing Basins Bottles „ Burette, Ripper's ,, Cups Paper Weight Thermometers, Silica Weighted Needle for Testing Cement Weights, Analytical, etc. .. No. 761 4142-4146, 6121-6123. 5384-5393. 5454-54°3 792 5025-5027 2196 . . . . 664 -. , '.. 3852 1447 3851 M55 2723-2725 327 475 2723-2725 6230-6237 . . 409-424 4347-4355 723. 4350 4349 4354-4355 435' 645 . . 1867, 4352-4353 4348 5019-5020 5070-5075 5967 5064 5918-5925 402 2513-2514 2550-2575 2535 2492-2494 2490-2539 3702-3703 2268-2278, 5076 3534-3537 910 5383-85383 5066 •• 733-735 732 731 730 5082 . . 208-248 4336 5494 891 I356-I371 5802-5807 6191 3569 5732 2123-2124 2118-2122 3'34 2123-2124 4383 2404 1791-1876 Becker's .. .. 1819-1829,1843,1866 Bunge's . . • . . . . 01803-1^.1803 Oertling's .. ..1808-1818,1831-1842,1865 Rider .. .. .. .. 1868 Rider, for Sp. Gr. Balances .. .. i?63 Sartorius .. .. .. 1801-1803 Weinzierl's Seed Testing Apparatus . . . . 5677 CROSS STREET • HATTON GARDETST, E-C 1282 BAIRD & TATI'CK (LOM)ON) LTD. INDEX. Weinzierl's Seed Testing Incubator „ Separator . . „ Sieves Weiss' Apparatus for Viscosity of Glue Westfield Granometer " Westminster " Centrifuges „ Shakers Westphal's Sp. Gr. Balance Wheatstone Bridge .. „ Boxes Wheel Bridges, Kohlrausch's Wheels, Driving ,, Set of, for Varying Speeds Whipple Temperature Indicators Wicks for Petroleum Oil Stoves Widal's Tubes Wild's (Roland), Calorimeters . . Will & Varrentrap's Nitrogen Bulbs Wills' Gas Measuring Burette Williams' Microtome . . Wilson's Chromometer ,, Rain Gauge . . Wine Flasks Winkler's Gas Absorption Apparatus Tubes Wire Cloth Wire Gauze, Iron ,. „ Iron, Asbestos Centre .. .. Nickel „ Nickel Triangles „ Weaving for Standard Sieves Witt's Filtering Apparatus ., Stirring Apparatus Wolfhugel's Counting Apparatus Wolpert's Air Tester Wood Block Cases Blocks .. for carrying Anthrax Specim ns Boxes for Samples Handles for Files Models of Crystals Specimens of Woodhead's Apparatus for Sterilising Pla um „ Flasks WoulfF s Bottles Wrench, Adjustable Wright's Blood Coagulation Tubes 8o 68 '23 '74 907 757 343 5318-531325 53327 5291291 55573 .. H62 .. -534 5(5627 .. 3593 .. 3624 .. 1566 542 .. 4385 .. 4384 ,3-4285 .. 6356 . . 2683 . 3954 554 4684 JO-2092 - 3948 507 - 633° . 2582 22-2324 . 4413 Spos 729 552 - 27-2131 2603 786 6-6116 2: 2748 . . 4688 .. 4687 6-6383 ^-4387 Yard Measure, Copy of Standard Yeast Flasks, various ,, Testing Apparatus Young's Fractional Distillation Tubes V Levels, improved Y Tubes Brass „ „ Glass Zeiss, Abb6 Apertometer ,, Drawing Apparatus ,, Stereoscopic Ocular „ Test Plate Achromatic Objectives Apochroma,tic ,, Bernhard's Drawing Table Binocular Magnifier Camera with Microscope . . Cardioid Condenser Condensers Dissecting Microscope Epidiascope Inverted Gas Lamp Mechanical Stage Mercury Lamps Microscopes and Accessories Nernst Lamps Nosepieces Ocular Micrometers Oculars, Compensating . . „ Huyghenian Optical Projection Screens Paraboloid Condenser ,, ,, Siedentopf Photo Micrographic Apparatus Projection Apparatus Refractometers Sliding Objective Changers Vertical Illuminator Zinc and Copper Electrodes Case for Root Development Killing Box Zimmer's Strop No. 3225 •• 503-505 4391-4401 4323-4325 6400-6403 4337 2199-2200, 4331 1122-1123 II II-III2 1125 II24 1108 1107 1141 1152 H55. "58 1175-1181 1144 1136-1140 "59-H73 page 240 1174 "45 1126-1128 1150-1151 1089-1191 1147-1149 1129-1131 1113-1121 I 1 10 1109 1185-1191 "43 1182-1184 1142 1156-1157 4944-4966, 4968-4987 1132-1135 "39 A5256 4582 666 1600 4N* I 3 University of Toronto ft w coi §* Library 1 * O 1 X 0 jyr H 0 J -H O\VER DO NOT / Q ® u II TJ -P c3 o X o ca REMOVE / 4 0 M | THE m -P eu t*. 10 * 'a) '' CARD §>J 0 0 -H to o a CD r-l; 0) w -p ,a FROM a) o E-. «H THIS at -^ to POCKET ft r-T • •r-t CO aJ (C 3 CO 0 4J *iH; cd w 0 Q Acme Library Card I'ocket £ — Unuer Pau "Kef. Ind« tFU«" 3 ** •< H Made by LIBRARY BUREAU